Commit Graph

501 Commits

Author SHA1 Message Date
Christian Brauner
abf08576af
fs: port vfs_*() helpers to struct mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-18 17:51:45 +01:00
Jeff Layton
5970e15dbc filelock: move file locking definitions to separate header file
The file locking definitions have lived in fs.h since the dawn of time,
but they are only used by a small subset of the source files that
include it.

Move the file locking definitions to a new header file, and add the
appropriate #include directives to the source files that need them. By
doing this we trim down fs.h a bit and limit the amount of rebuilding
that has to be done when we make changes to the file locking APIs.

Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: Steve French <stfrench@microsoft.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
2023-01-11 06:52:32 -05:00
Linus Torvalds
e1212e9b6f fs.vfsuid.conversion.v6.2
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Merge tag 'fs.vfsuid.conversion.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

Pull vfsuid updates from Christian Brauner:
 "Last cycle we introduced the vfs{g,u}id_t types and associated helpers
  to gain type safety when dealing with idmapped mounts. That initial
  work already converted a lot of places over but there were still some
  left,

  This converts all remaining places that still make use of non-type
  safe idmapping helpers to rely on the new type safe vfs{g,u}id based
  helpers.

  Afterwards it removes all the old non-type safe helpers"

* tag 'fs.vfsuid.conversion.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping:
  fs: remove unused idmapping helpers
  ovl: port to vfs{g,u}id_t and associated helpers
  fuse: port to vfs{g,u}id_t and associated helpers
  ima: use type safe idmapping helpers
  apparmor: use type safe idmapping helpers
  caps: use type safe idmapping helpers
  fs: use type safe idmapping helpers
  mnt_idmapping: add missing helpers
2022-12-12 19:20:05 -08:00
Linus Torvalds
cf619f8919 fs.ovl.setgid.v6.2
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Merge tag 'fs.ovl.setgid.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

Pull setgid inheritance updates from Christian Brauner:
 "This contains the work to make setgid inheritance consistent between
  modifying a file and when changing ownership or mode as this has been
  a repeated source of very subtle bugs. The gist is that we perform the
  same permission checks in the write path as we do in the ownership and
  mode changing paths after this series where we're currently doing
  different things.

  We've already made setgid inheritance a lot more consistent and
  reliable in the last releases by moving setgid stripping from the
  individual filesystems up into the vfs. This aims to make the logic
  even more consistent and easier to understand and also to fix
  long-standing overlayfs setgid inheritance bugs. Miklos was nice
  enough to just let me carry the trivial overlayfs patches from Amir
  too.

  Below is a more detailed explanation how the current difference in
  setgid handling lead to very subtle bugs exemplified via overlayfs
  which is a victim of the current rules. I hope this explains why I
  think taking the regression risk here is worth it.

  A long while ago I found a few setgid inheritance bugs in overlayfs in
  the write path in certain conditions. Amir recently picked this back
  up in [1] and I jumped on board to fix this more generally.

  On the surface all that overlayfs would need to fix setgid inheritance
  would be to call file_remove_privs() or file_modified() but actually
  that isn't enough because the setgid inheritance api is wildly
  inconsistent in that area.

  Before this pr setgid stripping in file_remove_privs()'s old
  should_remove_suid() helper was inconsistent with other parts of the
  vfs. Specifically, it only raises ATTR_KILL_SGID if the inode is
  S_ISGID and S_IXGRP but not if the inode isn't in the caller's groups
  and the caller isn't privileged over the inode although we require
  this already in setattr_prepare() and setattr_copy() and so all
  filesystem implement this requirement implicitly because they have to
  use setattr_{prepare,copy}() anyway.

  But the inconsistency shows up in setgid stripping bugs for overlayfs
  in xfstests (e.g., generic/673, generic/683, generic/685, generic/686,
  generic/687). For example, we test whether suid and setgid stripping
  works correctly when performing various write-like operations as an
  unprivileged user (fallocate, reflink, write, etc.):

      echo "Test 1 - qa_user, non-exec file $verb"
      setup_testfile
      chmod a+rws $junk_file
      commit_and_check "$qa_user" "$verb" 64k 64k

  The test basically creates a file with 6666 permissions. While the
  file has the S_ISUID and S_ISGID bits set it does not have the S_IXGRP
  set.

  On a regular filesystem like xfs what will happen is:

      sys_fallocate()
      -> vfs_fallocate()
         -> xfs_file_fallocate()
            -> file_modified()
               -> __file_remove_privs()
                  -> dentry_needs_remove_privs()
                     -> should_remove_suid()
                  -> __remove_privs()
                     newattrs.ia_valid = ATTR_FORCE | kill;
                     -> notify_change()
                        -> setattr_copy()

  In should_remove_suid() we can see that ATTR_KILL_SUID is raised
  unconditionally because the file in the test has S_ISUID set.

  But we also see that ATTR_KILL_SGID won't be set because while the
  file is S_ISGID it is not S_IXGRP (see above) which is a condition for
  ATTR_KILL_SGID being raised.

  So by the time we call notify_change() we have attr->ia_valid set to
  ATTR_KILL_SUID | ATTR_FORCE.

  Now notify_change() sees that ATTR_KILL_SUID is set and does:

      ia_valid      = attr->ia_valid |= ATTR_MODE
      attr->ia_mode = (inode->i_mode & ~S_ISUID);

  which means that when we call setattr_copy() later we will definitely
  update inode->i_mode. Note that attr->ia_mode still contains S_ISGID.

  Now we call into the filesystem's ->setattr() inode operation which
  will end up calling setattr_copy(). Since ATTR_MODE is set we will
  hit:

      if (ia_valid & ATTR_MODE) {
              umode_t mode = attr->ia_mode;
              vfsgid_t vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
              if (!vfsgid_in_group_p(vfsgid) &&
                  !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
                      mode &= ~S_ISGID;
              inode->i_mode = mode;
      }

  and since the caller in the test is neither capable nor in the group
  of the inode the S_ISGID bit is stripped.

  But assume the file isn't suid then ATTR_KILL_SUID won't be raised
  which has the consequence that neither the setgid nor the suid bits
  are stripped even though it should be stripped because the inode isn't
  in the caller's groups and the caller isn't privileged over the inode.

  If overlayfs is in the mix things become a bit more complicated and
  the bug shows up more clearly.

  When e.g., ovl_setattr() is hit from ovl_fallocate()'s call to
  file_remove_privs() then ATTR_KILL_SUID and ATTR_KILL_SGID might be
  raised but because the check in notify_change() is questioning the
  ATTR_KILL_SGID flag again by requiring S_IXGRP for it to be stripped
  the S_ISGID bit isn't removed even though it should be stripped:

      sys_fallocate()
      -> vfs_fallocate()
         -> ovl_fallocate()
            -> file_remove_privs()
               -> dentry_needs_remove_privs()
                  -> should_remove_suid()
               -> __remove_privs()
                  newattrs.ia_valid = ATTR_FORCE | kill;
                  -> notify_change()
                     -> ovl_setattr()
                        /* TAKE ON MOUNTER'S CREDS */
                        -> ovl_do_notify_change()
                           -> notify_change()
                        /* GIVE UP MOUNTER'S CREDS */
           /* TAKE ON MOUNTER'S CREDS */
           -> vfs_fallocate()
              -> xfs_file_fallocate()
                 -> file_modified()
                    -> __file_remove_privs()
                       -> dentry_needs_remove_privs()
                          -> should_remove_suid()
                       -> __remove_privs()
                          newattrs.ia_valid = attr_force | kill;
                          -> notify_change()

  The fix for all of this is to make file_remove_privs()'s
  should_remove_suid() helper perform the same checks as we already
  require in setattr_prepare() and setattr_copy() and have
  notify_change() not pointlessly requiring S_IXGRP again. It doesn't
  make any sense in the first place because the caller must calculate
  the flags via should_remove_suid() anyway which would raise
  ATTR_KILL_SGID

  Note that some xfstests will now fail as these patches will cause the
  setgid bit to be lost in certain conditions for unprivileged users
  modifying a setgid file when they would've been kept otherwise. I
  think this risk is worth taking and I explained and mentioned this
  multiple times on the list [2].

  Enforcing the rules consistently across write operations and
  chmod/chown will lead to losing the setgid bit in cases were it
  might've been retained before.

  While I've mentioned this a few times but it's worth repeating just to
  make sure that this is understood. For the sake of maintainability,
  consistency, and security this is a risk worth taking.

  If we really see regressions for workloads the fix is to have special
  setgid handling in the write path again with different semantics from
  chmod/chown and possibly additional duct tape for overlayfs. I'll
  update the relevant xfstests with if you should decide to merge this
  second setgid cleanup.

  Before that people should be aware that there might be failures for
  fstests where unprivileged users modify a setgid file"

Link: https://lore.kernel.org/linux-fsdevel/20221003123040.900827-1-amir73il@gmail.com [1]
Link: https://lore.kernel.org/linux-fsdevel/20221122142010.zchf2jz2oymx55qi@wittgenstein [2]

* tag 'fs.ovl.setgid.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping:
  fs: use consistent setgid checks in is_sxid()
  ovl: remove privs in ovl_fallocate()
  ovl: remove privs in ovl_copyfile()
  attr: use consistent sgid stripping checks
  attr: add setattr_should_drop_sgid()
  fs: move should_remove_suid()
  attr: add in_group_or_capable()
2022-12-12 19:03:10 -08:00
Christian Brauner
a2bd096fb2
fs: use type safe idmapping helpers
We already ported most parts and filesystems over for v6.0 to the new
vfs{g,u}id_t type and associated helpers for v6.0. Convert the remaining
places so we can remove all the old helpers.
This is a non-functional change.

Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-10-26 10:02:34 +02:00
Jeff Layton
3aca47127a fs: drop useless condition from inode_needs_update_time
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-10-23 18:09:54 -04:00
Christian Brauner
ed5a7047d2
attr: use consistent sgid stripping checks
Currently setgid stripping in file_remove_privs()'s should_remove_suid()
helper is inconsistent with other parts of the vfs. Specifically, it only
raises ATTR_KILL_SGID if the inode is S_ISGID and S_IXGRP but not if the
inode isn't in the caller's groups and the caller isn't privileged over the
inode although we require this already in setattr_prepare() and
setattr_copy() and so all filesystem implement this requirement implicitly
because they have to use setattr_{prepare,copy}() anyway.

But the inconsistency shows up in setgid stripping bugs for overlayfs in
xfstests (e.g., generic/673, generic/683, generic/685, generic/686,
generic/687). For example, we test whether suid and setgid stripping works
correctly when performing various write-like operations as an unprivileged
user (fallocate, reflink, write, etc.):

echo "Test 1 - qa_user, non-exec file $verb"
setup_testfile
chmod a+rws $junk_file
commit_and_check "$qa_user" "$verb" 64k 64k

The test basically creates a file with 6666 permissions. While the file has
the S_ISUID and S_ISGID bits set it does not have the S_IXGRP set. On a
regular filesystem like xfs what will happen is:

sys_fallocate()
-> vfs_fallocate()
   -> xfs_file_fallocate()
      -> file_modified()
         -> __file_remove_privs()
            -> dentry_needs_remove_privs()
               -> should_remove_suid()
            -> __remove_privs()
               newattrs.ia_valid = ATTR_FORCE | kill;
               -> notify_change()
                  -> setattr_copy()

In should_remove_suid() we can see that ATTR_KILL_SUID is raised
unconditionally because the file in the test has S_ISUID set.

But we also see that ATTR_KILL_SGID won't be set because while the file
is S_ISGID it is not S_IXGRP (see above) which is a condition for
ATTR_KILL_SGID being raised.

So by the time we call notify_change() we have attr->ia_valid set to
ATTR_KILL_SUID | ATTR_FORCE. Now notify_change() sees that
ATTR_KILL_SUID is set and does:

ia_valid = attr->ia_valid |= ATTR_MODE
attr->ia_mode = (inode->i_mode & ~S_ISUID);

which means that when we call setattr_copy() later we will definitely
update inode->i_mode. Note that attr->ia_mode still contains S_ISGID.

Now we call into the filesystem's ->setattr() inode operation which will
end up calling setattr_copy(). Since ATTR_MODE is set we will hit:

if (ia_valid & ATTR_MODE) {
        umode_t mode = attr->ia_mode;
        vfsgid_t vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
        if (!vfsgid_in_group_p(vfsgid) &&
            !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
                mode &= ~S_ISGID;
        inode->i_mode = mode;
}

and since the caller in the test is neither capable nor in the group of the
inode the S_ISGID bit is stripped.

But assume the file isn't suid then ATTR_KILL_SUID won't be raised which
has the consequence that neither the setgid nor the suid bits are stripped
even though it should be stripped because the inode isn't in the caller's
groups and the caller isn't privileged over the inode.

If overlayfs is in the mix things become a bit more complicated and the bug
shows up more clearly. When e.g., ovl_setattr() is hit from
ovl_fallocate()'s call to file_remove_privs() then ATTR_KILL_SUID and
ATTR_KILL_SGID might be raised but because the check in notify_change() is
questioning the ATTR_KILL_SGID flag again by requiring S_IXGRP for it to be
stripped the S_ISGID bit isn't removed even though it should be stripped:

sys_fallocate()
-> vfs_fallocate()
   -> ovl_fallocate()
      -> file_remove_privs()
         -> dentry_needs_remove_privs()
            -> should_remove_suid()
         -> __remove_privs()
            newattrs.ia_valid = ATTR_FORCE | kill;
            -> notify_change()
               -> ovl_setattr()
                  // TAKE ON MOUNTER'S CREDS
                  -> ovl_do_notify_change()
                     -> notify_change()
                  // GIVE UP MOUNTER'S CREDS
     // TAKE ON MOUNTER'S CREDS
     -> vfs_fallocate()
        -> xfs_file_fallocate()
           -> file_modified()
              -> __file_remove_privs()
                 -> dentry_needs_remove_privs()
                    -> should_remove_suid()
                 -> __remove_privs()
                    newattrs.ia_valid = attr_force | kill;
                    -> notify_change()

The fix for all of this is to make file_remove_privs()'s
should_remove_suid() helper to perform the same checks as we already
require in setattr_prepare() and setattr_copy() and have notify_change()
not pointlessly requiring S_IXGRP again. It doesn't make any sense in the
first place because the caller must calculate the flags via
should_remove_suid() anyway which would raise ATTR_KILL_SGID.

While we're at it we move should_remove_suid() from inode.c to attr.c
where it belongs with the rest of the iattr helpers. Especially since it
returns ATTR_KILL_S{G,U}ID flags. We also rename it to
setattr_should_drop_suidgid() to better reflect that it indicates both
setuid and setgid bit removal and also that it returns attr flags.

Running xfstests with this doesn't report any regressions. We should really
try and use consistent checks.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-10-18 10:09:47 +02:00
Christian Brauner
e243e3f94c
fs: move should_remove_suid()
Move the helper from inode.c to attr.c. This keeps the the core of the
set{g,u}id stripping logic in one place when we add follow-up changes.
It is the better place anyway, since should_remove_suid() returns
ATTR_KILL_S{G,U}ID flags.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-10-18 10:09:46 +02:00
Christian Brauner
11c2a8700c
attr: add in_group_or_capable()
In setattr_{copy,prepare}() we need to perform the same permission
checks to determine whether we need to drop the setgid bit or not.
Instead of open-coding it twice add a simple helper the encapsulates the
logic. We will reuse this helpers to make dropping the setgid bit during
write operations more consistent in a follow up patch.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-10-18 10:09:43 +02:00
Linus Torvalds
46811b5cb3 saner inode_init_always()
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Merge tag 'pull-inode' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs inode update from Al Viro:
 "Saner inode_init_always(), also fixing a nilfs problem"

* tag 'pull-inode' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: fix UAF/GPF bug in nilfs_mdt_destroy
2022-10-06 16:49:00 -07:00
Dongliang Mu
2e488f1375 fs: fix UAF/GPF bug in nilfs_mdt_destroy
In alloc_inode, inode_init_always() could return -ENOMEM if
security_inode_alloc() fails, which causes inode->i_private
uninitialized. Then nilfs_is_metadata_file_inode() returns
true and nilfs_free_inode() wrongly calls nilfs_mdt_destroy(),
which frees the uninitialized inode->i_private
and leads to crashes(e.g., UAF/GPF).

Fix this by moving security_inode_alloc just prior to
this_cpu_inc(nr_inodes)

Link: https://lkml.kernel.org/r/CAFcO6XOcf1Jj2SeGt=jJV59wmhESeSKpfR0omdFRq+J9nD1vfQ@mail.gmail.com
Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Reported-by: Hao Sun <sunhao.th@gmail.com>
Reported-by: Jiacheng Xu <stitch@zju.edu.cn>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-09-01 17:30:24 -04:00
Stefan Roesch
41191cf6bf
fs: __file_remove_privs(): restore call to inode_has_no_xattr()
This restores the call to inode_has_no_xattr() in the function
__file_remove_privs(). In case the dentry_meeds_remove_privs() returned
0, the function inode_has_no_xattr() was not called.

Signed-off-by: Stefan Roesch <shr@fb.com>
Fixes: faf99b5635 ("fs: add __remove_file_privs() with flags parameter")
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Link: https://lore.kernel.org/r/20220816153158.1925040-1-shr@fb.com
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-08-18 09:39:33 +02:00
Linus Torvalds
786da5da56 We have a good pile of various fixes and cleanups from Xiubo, Jeff,
Luis and others, almost exclusively in the filesystem.  Several patches
 touch files outside of our normal purview to set the stage for bringing
 in Jeff's long awaited ceph+fscrypt series in the near future.  All of
 them have appropriate acks and sat in linux-next for a while.
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Merge tag 'ceph-for-5.20-rc1' of https://github.com/ceph/ceph-client

Pull ceph updates from Ilya Dryomov:
 "We have a good pile of various fixes and cleanups from Xiubo, Jeff,
  Luis and others, almost exclusively in the filesystem.

  Several patches touch files outside of our normal purview to set the
  stage for bringing in Jeff's long awaited ceph+fscrypt series in the
  near future. All of them have appropriate acks and sat in linux-next
  for a while"

* tag 'ceph-for-5.20-rc1' of https://github.com/ceph/ceph-client: (27 commits)
  libceph: clean up ceph_osdc_start_request prototype
  libceph: fix ceph_pagelist_reserve() comment typo
  ceph: remove useless check for the folio
  ceph: don't truncate file in atomic_open
  ceph: make f_bsize always equal to f_frsize
  ceph: flush the dirty caps immediatelly when quota is approaching
  libceph: print fsid and epoch with osd id
  libceph: check pointer before assigned to "c->rules[]"
  ceph: don't get the inline data for new creating files
  ceph: update the auth cap when the async create req is forwarded
  ceph: make change_auth_cap_ses a global symbol
  ceph: fix incorrect old_size length in ceph_mds_request_args
  ceph: switch back to testing for NULL folio->private in ceph_dirty_folio
  ceph: call netfs_subreq_terminated with was_async == false
  ceph: convert to generic_file_llseek
  ceph: fix the incorrect comment for the ceph_mds_caps struct
  ceph: don't leak snap_rwsem in handle_cap_grant
  ceph: prevent a client from exceeding the MDS maximum xattr size
  ceph: choose auth MDS for getxattr with the Xs caps
  ceph: add session already open notify support
  ...
2022-08-11 12:41:07 -07:00
Linus Torvalds
426b4ca2d6 fs.setgid.v6.0
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Merge tag 'fs.setgid.v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull setgid updates from Christian Brauner:
 "This contains the work to move setgid stripping out of individual
  filesystems and into the VFS itself.

  Creating files that have both the S_IXGRP and S_ISGID bit raised in
  directories that themselves have the S_ISGID bit set requires
  additional privileges to avoid security issues.

  When a filesystem creates a new inode it needs to take care that the
  caller is either in the group of the newly created inode or they have
  CAP_FSETID in their current user namespace and are privileged over the
  parent directory of the new inode. If any of these two conditions is
  true then the S_ISGID bit can be raised for an S_IXGRP file and if not
  it needs to be stripped.

  However, there are several key issues with the current implementation:

   - S_ISGID stripping logic is entangled with umask stripping.

     For example, if the umask removes the S_IXGRP bit from the file
     about to be created then the S_ISGID bit will be kept.

     The inode_init_owner() helper is responsible for S_ISGID stripping
     and is called before posix_acl_create(). So we can end up with two
     different orderings:

     1. FS without POSIX ACL support

        First strip umask then strip S_ISGID in inode_init_owner().

        In other words, if a filesystem doesn't support or enable POSIX
        ACLs then umask stripping is done directly in the vfs before
        calling into the filesystem:

     2. FS with POSIX ACL support

        First strip S_ISGID in inode_init_owner() then strip umask in
        posix_acl_create().

        In other words, if the filesystem does support POSIX ACLs then
        unmask stripping may be done in the filesystem itself when
        calling posix_acl_create().

     Note that technically filesystems are free to impose their own
     ordering between posix_acl_create() and inode_init_owner() meaning
     that there's additional ordering issues that influence S_ISGID
     inheritance.

     (Note that the commit message of commit 1639a49ccd ("fs: move
     S_ISGID stripping into the vfs_*() helpers") gets the ordering
     between inode_init_owner() and posix_acl_create() the wrong way
     around. I realized this too late.)

   - Filesystems that don't rely on inode_init_owner() don't get S_ISGID
     stripping logic.

     While that may be intentional (e.g. network filesystems might just
     defer setgid stripping to a server) it is often just a security
     issue.

     Note that mandating the use of inode_init_owner() was proposed as
     an alternative solution but that wouldn't fix the ordering issues
     and there are examples such as afs where the use of
     inode_init_owner() isn't possible.

     In any case, we should also try the cleaner and generalized
     solution first before resorting to this approach.

   - We still have S_ISGID inheritance bugs years after the initial
     round of S_ISGID inheritance fixes:

       e014f37db1 ("xfs: use setattr_copy to set vfs inode attributes")
       01ea173e10 ("xfs: fix up non-directory creation in SGID directories")
       fd84bfdddd ("ceph: fix up non-directory creation in SGID directories")

  All of this led us to conclude that the current state is too messy.
  While we won't be able to make it completely clean as
  posix_acl_create() is still a filesystem specific call we can improve
  the S_SIGD stripping situation quite a bit by hoisting it out of
  inode_init_owner() and into the respective vfs creation operations.

  The obvious advantage is that we don't need to rely on individual
  filesystems getting S_ISGID stripping right and instead can
  standardize the ordering between S_ISGID and umask stripping directly
  in the VFS.

  A few short implementation notes:

   - The stripping logic needs to happen in vfs_*() helpers for the sake
     of stacking filesystems such as overlayfs that rely on these
     helpers taking care of S_ISGID stripping.

   - Security hooks have never seen the mode as it is ultimately seen by
     the filesystem because of the ordering issue we mentioned. Nothing
     is changed for them. We simply continue to strip the umask before
     passing the mode down to the security hooks.

   - The following filesystems use inode_init_owner() and thus relied on
     S_ISGID stripping: spufs, 9p, bfs, btrfs, ext2, ext4, f2fs,
     hfsplus, hugetlbfs, jfs, minix, nilfs2, ntfs3, ocfs2, omfs,
     overlayfs, ramfs, reiserfs, sysv, ubifs, udf, ufs, xfs, zonefs,
     bpf, tmpfs.

     We've audited all callchains as best as we could. More details can
     be found in the commit message to 1639a49ccd ("fs: move S_ISGID
     stripping into the vfs_*() helpers")"

* tag 'fs.setgid.v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  ceph: rely on vfs for setgid stripping
  fs: move S_ISGID stripping into the vfs_*() helpers
  fs: Add missing umask strip in vfs_tmpfile
  fs: add mode_strip_sgid() helper
2022-08-09 09:52:28 -07:00
Linus Torvalds
f00654007f Folio changes for 6.0
- Fix an accounting bug that made NR_FILE_DIRTY grow without limit
    when running xfstests
 
  - Convert more of mpage to use folios
 
  - Remove add_to_page_cache() and add_to_page_cache_locked()
 
  - Convert find_get_pages_range() to filemap_get_folios()
 
  - Improvements to the read_cache_page() family of functions
 
  - Remove a few unnecessary checks of PageError
 
  - Some straightforward filesystem conversions to use folios
 
  - Split PageMovable users out from address_space_operations into their
    own movable_operations
 
  - Convert aops->migratepage to aops->migrate_folio
 
  - Remove nobh support (Christoph Hellwig)
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Merge tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache

Pull folio updates from Matthew Wilcox:

 - Fix an accounting bug that made NR_FILE_DIRTY grow without limit
   when running xfstests

 - Convert more of mpage to use folios

 - Remove add_to_page_cache() and add_to_page_cache_locked()

 - Convert find_get_pages_range() to filemap_get_folios()

 - Improvements to the read_cache_page() family of functions

 - Remove a few unnecessary checks of PageError

 - Some straightforward filesystem conversions to use folios

 - Split PageMovable users out from address_space_operations into
   their own movable_operations

 - Convert aops->migratepage to aops->migrate_folio

 - Remove nobh support (Christoph Hellwig)

* tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache: (78 commits)
  fs: remove the NULL get_block case in mpage_writepages
  fs: don't call ->writepage from __mpage_writepage
  fs: remove the nobh helpers
  jfs: stop using the nobh helper
  ext2: remove nobh support
  ntfs3: refactor ntfs_writepages
  mm/folio-compat: Remove migration compatibility functions
  fs: Remove aops->migratepage()
  secretmem: Convert to migrate_folio
  hugetlb: Convert to migrate_folio
  aio: Convert to migrate_folio
  f2fs: Convert to filemap_migrate_folio()
  ubifs: Convert to filemap_migrate_folio()
  btrfs: Convert btrfs_migratepage to migrate_folio
  mm/migrate: Add filemap_migrate_folio()
  mm/migrate: Convert migrate_page() to migrate_folio()
  nfs: Convert to migrate_folio
  btrfs: Convert btree_migratepage to migrate_folio
  mm/migrate: Convert expected_page_refs() to folio_expected_refs()
  mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio()
  ...
2022-08-03 10:35:43 -07:00
Jeff Layton
18cc912b8a fs: change test in inode_insert5 for adding to the sb list
inode_insert5 currently looks at I_CREATING to decide whether to insert
the inode into the sb list. This test is a bit ambiguous, as I_CREATING
state is not directly related to that list.

This test is also problematic for some upcoming ceph changes to add
fscrypt support. We need to be able to allocate an inode using new_inode
and insert it into the hash later iff we end up using it, and doing that
now means that we double add it and corrupt the list.

What we really want to know in this test is whether the inode is already
in its superblock list, and then add it if it isn't. Have it test for
list_empty instead and ensure that we always initialize the list by
doing it in inode_init_once. It's only ever removed from the list with
list_del_init, so that should be sufficient.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2022-08-03 00:54:11 +02:00
Stefan Roesch
66fa3cedf1 fs: Add async write file modification handling.
This adds a file_modified_async() function to return -EAGAIN if the
request either requires to remove privileges or needs to update the file
modification time. This is required for async buffered writes, so the
request gets handled in the io worker of io-uring.

Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220623175157.1715274-11-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:32 -06:00
Stefan Roesch
6a2aa5d85d fs: Split off inode_needs_update_time and __file_update_time
This splits off the functions inode_needs_update_time() and
__file_update_time() from the function file_update_time().

This is required to support async buffered writes.
No intended functional changes in this patch.

Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220623175157.1715274-10-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:31 -06:00
Stefan Roesch
faf99b5635 fs: add __remove_file_privs() with flags parameter
This adds the function __remove_file_privs, which allows the caller to
pass the kiocb flags parameter.

No intended functional changes in this patch.

Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220623175157.1715274-9-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:31 -06:00
Yang Xu
1639a49ccd
fs: move S_ISGID stripping into the vfs_*() helpers
Move setgid handling out of individual filesystems and into the VFS
itself to stop the proliferation of setgid inheritance bugs.

Creating files that have both the S_IXGRP and S_ISGID bit raised in
directories that themselves have the S_ISGID bit set requires additional
privileges to avoid security issues.

When a filesystem creates a new inode it needs to take care that the
caller is either in the group of the newly created inode or they have
CAP_FSETID in their current user namespace and are privileged over the
parent directory of the new inode. If any of these two conditions is
true then the S_ISGID bit can be raised for an S_IXGRP file and if not
it needs to be stripped.

However, there are several key issues with the current implementation:

* S_ISGID stripping logic is entangled with umask stripping.

  If a filesystem doesn't support or enable POSIX ACLs then umask
  stripping is done directly in the vfs before calling into the
  filesystem.
  If the filesystem does support POSIX ACLs then unmask stripping may be
  done in the filesystem itself when calling posix_acl_create().

  Since umask stripping has an effect on S_ISGID inheritance, e.g., by
  stripping the S_IXGRP bit from the file to be created and all relevant
  filesystems have to call posix_acl_create() before inode_init_owner()
  where we currently take care of S_ISGID handling S_ISGID handling is
  order dependent. IOW, whether or not you get a setgid bit depends on
  POSIX ACLs and umask and in what order they are called.

  Note that technically filesystems are free to impose their own
  ordering between posix_acl_create() and inode_init_owner() meaning
  that there's additional ordering issues that influence S_SIGID
  inheritance.

* Filesystems that don't rely on inode_init_owner() don't get S_ISGID
  stripping logic.

  While that may be intentional (e.g. network filesystems might just
  defer setgid stripping to a server) it is often just a security issue.

This is not just ugly it's unsustainably messy especially since we do
still have bugs in this area years after the initial round of setgid
bugfixes.

So the current state is quite messy and while we won't be able to make
it completely clean as posix_acl_create() is still a filesystem specific
call we can improve the S_SIGD stripping situation quite a bit by
hoisting it out of inode_init_owner() and into the vfs creation
operations. This means we alleviate the burden for filesystems to handle
S_ISGID stripping correctly and can standardize the ordering between
S_ISGID and umask stripping in the vfs.

We add a new helper vfs_prepare_mode() so S_ISGID handling is now done
in the VFS before umask handling. This has S_ISGID handling is
unaffected unaffected by whether umask stripping is done by the VFS
itself (if no POSIX ACLs are supported or enabled) or in the filesystem
in posix_acl_create() (if POSIX ACLs are supported).

The vfs_prepare_mode() helper is called directly in vfs_*() helpers that
create new filesystem objects. We need to move them into there to make
sure that filesystems like overlayfs hat have callchains like:

sys_mknod()
-> do_mknodat(mode)
   -> .mknod = ovl_mknod(mode)
      -> ovl_create(mode)
         -> vfs_mknod(mode)

get S_ISGID stripping done when calling into lower filesystems via
vfs_*() creation helpers. Moving vfs_prepare_mode() into e.g.
vfs_mknod() takes care of that. This is in any case semantically cleaner
because S_ISGID stripping is VFS security requirement.

Security hooks so far have seen the mode with the umask applied but
without S_ISGID handling done. The relevant hooks are called outside of
vfs_*() creation helpers so by calling vfs_prepare_mode() from vfs_*()
helpers the security hooks would now see the mode without umask
stripping applied. For now we fix this by passing the mode with umask
settings applied to not risk any regressions for LSM hooks. IOW, nothing
changes for LSM hooks. It is worth pointing out that security hooks
never saw the mode that is seen by the filesystem when actually creating
the file. They have always been completely misplaced for that to work.

The following filesystems use inode_init_owner() and thus relied on
S_ISGID stripping: spufs, 9p, bfs, btrfs, ext2, ext4, f2fs, hfsplus,
hugetlbfs, jfs, minix, nilfs2, ntfs3, ocfs2, omfs, overlayfs, ramfs,
reiserfs, sysv, ubifs, udf, ufs, xfs, zonefs, bpf, tmpfs.

All of the above filesystems end up calling inode_init_owner() when new
filesystem objects are created through the ->mkdir(), ->mknod(),
->create(), ->tmpfile(), ->rename() inode operations.

Since directories always inherit the S_ISGID bit with the exception of
xfs when irix_sgid_inherit mode is turned on S_ISGID stripping doesn't
apply. The ->symlink() and ->link() inode operations trivially inherit
the mode from the target and the ->rename() inode operation inherits the
mode from the source inode. All other creation inode operations will get
S_ISGID handling via vfs_prepare_mode() when called from their relevant
vfs_*() helpers.

In addition to this there are filesystems which allow the creation of
filesystem objects through ioctl()s or - in the case of spufs -
circumventing the vfs in other ways. If filesystem objects are created
through ioctl()s the vfs doesn't know about it and can't apply regular
permission checking including S_ISGID logic. Therfore, a filesystem
relying on S_ISGID stripping in inode_init_owner() in their ioctl()
callpath will be affected by moving this logic into the vfs. We audited
those filesystems:

* btrfs allows the creation of filesystem objects through various
  ioctls(). Snapshot creation literally takes a snapshot and so the mode
  is fully preserved and S_ISGID stripping doesn't apply.

  Creating a new subvolum relies on inode_init_owner() in
  btrfs_new_subvol_inode() but only creates directories and doesn't
  raise S_ISGID.

* ocfs2 has a peculiar implementation of reflinks. In contrast to e.g.
  xfs and btrfs FICLONE/FICLONERANGE ioctl() that is only concerned with
  the actual extents ocfs2 uses a separate ioctl() that also creates the
  target file.

  Iow, ocfs2 circumvents the vfs entirely here and did indeed rely on
  inode_init_owner() to strip the S_ISGID bit. This is the only place
  where a filesystem needs to call mode_strip_sgid() directly but this
  is self-inflicted pain.

* spufs doesn't go through the vfs at all and doesn't use ioctl()s
  either. Instead it has a dedicated system call spufs_create() which
  allows the creation of filesystem objects. But spufs only creates
  directories and doesn't allo S_SIGID bits, i.e. it specifically only
  allows 0777 bits.

* bpf uses vfs_mkobj() but also doesn't allow S_ISGID bits to be created.

The patch will have an effect on ext2 when the EXT2_MOUNT_GRPID mount
option is used, on ext4 when the EXT4_MOUNT_GRPID mount option is used,
and on xfs when the XFS_FEAT_GRPID mount option is used. When any of
these filesystems are mounted with their respective GRPID option then
newly created files inherit the parent directories group
unconditionally. In these cases non of the filesystems call
inode_init_owner() and thus did never strip the S_ISGID bit for newly
created files. Moving this logic into the VFS means that they now get
the S_ISGID bit stripped. This is a user visible change. If this leads
to regressions we will either need to figure out a better way or we need
to revert. However, given the various setgid bugs that we found just in
the last two years this is a regression risk we should take.

Associated with this change is a new set of fstests to enforce the
semantics for all new filesystems.

Link: https://lore.kernel.org/ceph-devel/20220427092201.wvsdjbnc7b4dttaw@wittgenstein [1]
Link: e014f37db1 ("xfs: use setattr_copy to set vfs inode attributes") [2]
Link: 01ea173e10 ("xfs: fix up non-directory creation in SGID directories") [3]
Link: fd84bfdddd ("ceph: fix up non-directory creation in SGID directories") [4]
Link: https://lore.kernel.org/r/1657779088-2242-3-git-send-email-xuyang2018.jy@fujitsu.com
Suggested-by: Dave Chinner <david@fromorbit.com>
Suggested-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-and-Tested-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
[<brauner@kernel.org>: rewrote commit message]
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-07-21 11:34:16 +02:00
Yang Xu
2b3416ceff
fs: add mode_strip_sgid() helper
Add a dedicated helper to handle the setgid bit when creating a new file
in a setgid directory. This is a preparatory patch for moving setgid
stripping into the vfs. The patch contains no functional changes.

Currently the setgid stripping logic is open-coded directly in
inode_init_owner() and the individual filesystems are responsible for
handling setgid inheritance. Since this has proven to be brittle as
evidenced by old issues we uncovered over the last months (see [1] to
[3] below) we will try to move this logic into the vfs.

Link: e014f37db1 ("xfs: use setattr_copy to set vfs inode attributes") [1]
Link: 01ea173e10 ("xfs: fix up non-directory creation in SGID directories") [2]
Link: fd84bfdddd ("ceph: fix up non-directory creation in SGID directories") [3]
Link: https://lore.kernel.org/r/1657779088-2242-1-git-send-email-xuyang2018.jy@fujitsu.com
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-and-Tested-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-07-19 15:13:02 +02:00
Matthew Wilcox (Oracle)
6ffcd825e7 mm: Remove __delete_from_page_cache()
This wrapper is no longer used.  Remove it and all references to it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-06-29 08:51:05 -04:00
Jchao Sun
10e1407310 writeback: Fix inode->i_io_list not be protected by inode->i_lock error
Commit b35250c081 ("writeback: Protect inode->i_io_list with
inode->i_lock") made inode->i_io_list not only protected by
wb->list_lock but also inode->i_lock, but inode_io_list_move_locked()
was missed. Add lock there and also update comment describing
things protected by inode->i_lock. This also fixes a race where
__mark_inode_dirty() could move inode under flush worker's hands
and thus sync(2) could miss writing some inodes.

Fixes: b35250c081 ("writeback: Protect inode->i_io_list with inode->i_lock")
Link: https://lore.kernel.org/r/20220524150540.12552-1-sunjunchao2870@gmail.com
CC: stable@vger.kernel.org
Signed-off-by: Jchao Sun <sunjunchao2870@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2022-06-06 09:54:30 +02:00
Muchun Song
8b9f3ac5b0 fs: introduce alloc_inode_sb() to allocate filesystems specific inode
The allocated inode cache is supposed to be added to its memcg list_lru
which should be allocated as well in advance.  That can be done by
kmem_cache_alloc_lru() which allocates object and list_lru.  The file
systems is main user of it.  So introduce alloc_inode_sb() to allocate
file system specific inodes and set up the inode reclaim context
properly.  The file system is supposed to use alloc_inode_sb() to
allocate inodes.

In later patches, we will convert all users to the new API.

Link: https://lkml.kernel.org/r/20220228122126.37293-4-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Alex Shi <alexs@kernel.org>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kari Argillander <kari.argillander@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:03 -07:00
Luis Chamberlain
1d67fe5850 fs: move inode sysctls to its own file
Patch series "sysctl: 4th set of kernel/sysctl cleanups".

This is slimming down the fs uses of kernel/sysctl.c to the point that
the next step is to just get rid of the fs base directory for it and
move that elsehwere, so that next patch series starts dealing with that
to demo how we can end up cleaning up a full base directory from
kernel/sysctl.c, one at a time.

This patch (of 9):

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

So move the inode sysctls to its own file.  Since we are no longer using
this outside of fs/ remove the extern declaration of its respective proc
helper.

We use early_initcall() as it is the earliest we can use.

[arnd@arndb.de: avoid unused-variable warning]
  Link: https://lkml.kernel.org/r/20211203190123.874239-1-arnd@kernel.org

Link: https://lkml.kernel.org/r/20211129205548.605569-1-mcgrof@kernel.org
Link: https://lkml.kernel.org/r/20211129205548.605569-2-mcgrof@kernel.org
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-22 08:33:35 +02:00
Matthew Wilcox (Oracle)
3e9d80a891 mm,fs: split dump_mapping() out from dump_page()
dump_mapping() is a big chunk of dump_page(), and it'd be handy to be
able to call it when we don't have a struct page.  Split it out and move
it to fs/inode.c.  Take the opportunity to simplify some of the debug
messages a little.

Link: https://lkml.kernel.org/r/20211121121056.2870061-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15 16:30:26 +02:00
Matthew Wilcox (Oracle)
ff36da69bc fs: Remove FS_THP_SUPPORT
Instead of setting a bit in the fs_flags to set a bit in the
address_space, set the bit in the address_space directly.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2021-11-17 10:36:35 -05:00
Linus Torvalds
59a2ceeef6 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
 "87 patches.

  Subsystems affected by this patch series: mm (pagecache and hugetlb),
  procfs, misc, MAINTAINERS, lib, checkpatch, binfmt, kallsyms, ramfs,
  init, codafs, nilfs2, hfs, crash_dump, signals, seq_file, fork,
  sysvfs, kcov, gdb, resource, selftests, and ipc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (87 commits)
  ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL
  ipc: check checkpoint_restore_ns_capable() to modify C/R proc files
  selftests/kselftest/runner/run_one(): allow running non-executable files
  virtio-mem: disallow mapping virtio-mem memory via /dev/mem
  kernel/resource: disallow access to exclusive system RAM regions
  kernel/resource: clean up and optimize iomem_is_exclusive()
  scripts/gdb: handle split debug for vmlinux
  kcov: replace local_irq_save() with a local_lock_t
  kcov: avoid enable+disable interrupts if !in_task()
  kcov: allocate per-CPU memory on the relevant node
  Documentation/kcov: define `ip' in the example
  Documentation/kcov: include types.h in the example
  sysv: use BUILD_BUG_ON instead of runtime check
  kernel/fork.c: unshare(): use swap() to make code cleaner
  seq_file: fix passing wrong private data
  seq_file: move seq_escape() to a header
  signal: remove duplicate include in signal.h
  crash_dump: remove duplicate include in crash_dump.h
  crash_dump: fix boolreturn.cocci warning
  hfs/hfsplus: use WARN_ON for sanity check
  ...
2021-11-09 10:11:53 -08:00
Johannes Weiner
51b8c1fe25 vfs: keep inodes with page cache off the inode shrinker LRU
Historically (pre-2.5), the inode shrinker used to reclaim only empty
inodes and skip over those that still contained page cache.  This caused
problems on highmem hosts: struct inode could put fill lowmem zones
before the cache was getting reclaimed in the highmem zones.

To address this, the inode shrinker started to strip page cache to
facilitate reclaiming lowmem.  However, this comes with its own set of
problems: the shrinkers may drop actively used page cache just because
the inodes are not currently open or dirty - think working with a large
git tree.  It further doesn't respect cgroup memory protection settings
and can cause priority inversions between containers.

Nowadays, the page cache also holds non-resident info for evicted cache
pages in order to detect refaults.  We've come to rely heavily on this
data inside reclaim for protecting the cache workingset and driving swap
behavior.  We also use it to quantify and report workload health through
psi.  The latter in turn is used for fleet health monitoring, as well as
driving automated memory sizing of workloads and containers, proactive
reclaim and memory offloading schemes.

The consequences of dropping page cache prematurely is that we're seeing
subtle and not-so-subtle failures in all of the above-mentioned
scenarios, with the workload generally entering unexpected thrashing
states while losing the ability to reliably detect it.

To fix this on non-highmem systems at least, going back to rotating
inodes on the LRU isn't feasible.  We've tried (commit a76cf1a474
("mm: don't reclaim inodes with many attached pages")) and failed
(commit 69056ee6a8 ("Revert "mm: don't reclaim inodes with many
attached pages"")).

The issue is mostly that shrinker pools attract pressure based on their
size, and when objects get skipped the shrinkers remember this as
deferred reclaim work.  This accumulates excessive pressure on the
remaining inodes, and we can quickly eat into heavily used ones, or
dirty ones that require IO to reclaim, when there potentially is plenty
of cold, clean cache around still.

Instead, this patch keeps populated inodes off the inode LRU in the
first place - just like an open file or dirty state would.  An otherwise
clean and unused inode then gets queued when the last cache entry
disappears.  This solves the problem without reintroducing the reclaim
issues, and generally is a bit more scalable than having to wade through
potentially hundreds of thousands of busy inodes.

Locking is a bit tricky because the locks protecting the inode state
(i_lock) and the inode LRU (lru_list.lock) don't nest inside the
irq-safe page cache lock (i_pages.xa_lock).  Page cache deletions are
serialized through i_lock, taken before the i_pages lock, to make sure
depopulated inodes are queued reliably.  Additions may race with
deletions, but we'll check again in the shrinker.  If additions race
with the shrinker itself, we're protected by the i_lock: if find_inode()
or iput() win, the shrinker will bail on the elevated i_count or
I_REFERENCED; if the shrinker wins and goes ahead with the inode, it
will set I_FREEING and inhibit further igets(), which will cause the
other side to create a new instance of the inode instead.

Link: https://lkml.kernel.org/r/20210614211904.14420-4-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 10:02:48 -08:00
Josef Bacik
e60feb445f fs: export an inode_update_time helper
If you already have an inode and need to update the time on the inode
there is no way to do this properly.  Export this helper to allow file
systems to update time on the inode so the appropriate handler is
called, either ->update_time or generic_update_time.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26 19:08:08 +02:00
Sebastian Andrzej Siewior
23ca067b32 mm: Fully initialize invalidate_lock, amend lock class later
The function __init_rwsem() is not part of the official API, it just a helper
function used by init_rwsem().
Changing the lock's class and name should be done by using
lockdep_set_class_and_name() after the has been fully initialized. The overhead
of the additional class struct and setting it twice is negligible and it works
across all locks.

Fully initialize the lock with init_rwsem() and then set the custom class and
name for the lock.

Fixes: 730633f0b7 ("mm: Protect operations adding pages to page cache with invalidate_lock")
Link: https://lore.kernel.org/r/20210901084403.g4fezi23cixemlhh@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-09-17 13:39:23 +02:00
Linus Torvalds
14726903c8 Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "173 patches.

  Subsystems affected by this series: ia64, ocfs2, block, and mm (debug,
  pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
  bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure,
  hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock,
  oom-kill, migration, ksm, percpu, vmstat, and madvise)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits)
  mm/madvise: add MADV_WILLNEED to process_madvise()
  mm/vmstat: remove unneeded return value
  mm/vmstat: simplify the array size calculation
  mm/vmstat: correct some wrong comments
  mm/percpu,c: remove obsolete comments of pcpu_chunk_populated()
  selftests: vm: add COW time test for KSM pages
  selftests: vm: add KSM merging time test
  mm: KSM: fix data type
  selftests: vm: add KSM merging across nodes test
  selftests: vm: add KSM zero page merging test
  selftests: vm: add KSM unmerge test
  selftests: vm: add KSM merge test
  mm/migrate: correct kernel-doc notation
  mm: wire up syscall process_mrelease
  mm: introduce process_mrelease system call
  memblock: make memblock_find_in_range method private
  mm/mempolicy.c: use in_task() in mempolicy_slab_node()
  mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies
  mm/mempolicy: advertise new MPOL_PREFERRED_MANY
  mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY
  ...
2021-09-03 10:08:28 -07:00
Johannes Weiner
7ae12c809f fs: inode: count invalidated shadow pages in pginodesteal
pginodesteal is supposed to capture the impact that inode reclaim has on
the page cache state.  Currently, it doesn't consider shadow pages that
get dropped this way, even though this can have a significant impact on
paging behavior, memory pressure calculations etc.

To improve visibility into these effects, make sure shadow pages get
counted when they get dropped through inode reclaim.

This changes the return value semantics of invalidate_mapping_pages()
semantics slightly, but the only two users are the inode shrinker itsel
and a usb driver that logs it for debugging purposes.

Link: https://lkml.kernel.org/r/20210614211904.14420-3-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:10 -07:00
Jan Kara
730633f0b7 mm: Protect operations adding pages to page cache with invalidate_lock
Currently, serializing operations such as page fault, read, or readahead
against hole punching is rather difficult. The basic race scheme is
like:

fallocate(FALLOC_FL_PUNCH_HOLE)			read / fault / ..
  truncate_inode_pages_range()
						  <create pages in page
						   cache here>
  <update fs block mapping and free blocks>

Now the problem is in this way read / page fault / readahead can
instantiate pages in page cache with potentially stale data (if blocks
get quickly reused). Avoiding this race is not simple - page locks do
not work because we want to make sure there are *no* pages in given
range. inode->i_rwsem does not work because page fault happens under
mmap_sem which ranks below inode->i_rwsem. Also using it for reads makes
the performance for mixed read-write workloads suffer.

So create a new rw_semaphore in the address_space - invalidate_lock -
that protects adding of pages to page cache for page faults / reads /
readahead.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-07-13 13:14:27 +02:00
Hugh Dickins
786b31121a mm: remove nrexceptional from inode: remove BUG_ON
clear_inode()'s BUG_ON(!mapping_empty(&inode->i_data)) is unsafe: we
know of two ways in which nodes can and do (on rare occasions) get left
behind.  Until those are fixed, do not BUG_ON() nor even WARN_ON().

Yes, this will then leak those nodes (or the next user of the struct
inode may use them); but this has been happening for years, and the new
BUG_ON(!mapping_empty) was only guilty of revealing that.  A proper fix
will follow, but no hurry.

Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2104292229380.16080@eggly.anvils
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05 11:27:20 -07:00
Matthew Wilcox (Oracle)
8bc3c481b3 mm: remove nrexceptional from inode
We no longer track anything in nrexceptional, so remove it, saving 8 bytes
per inode.

Link: https://lkml.kernel.org/r/20201026151849.24232-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05 11:27:20 -07:00
Linus Torvalds
34a456eb1f fs.idmapped.helpers.v5.13
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Merge tag 'fs.idmapped.helpers.v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull fs mapping helper updates from Christian Brauner:
 "This adds kernel-doc to all new idmapping helpers and improves their
  naming which was triggered by a discussion with some fs developers.
  Some of the names are based on suggestions by Vivek and Al.

  Also remove the open-coded permission checking in a few places with
  simple helpers. Overall this should lead to more clarity and make it
  easier to maintain"

* tag 'fs.idmapped.helpers.v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  fs: introduce two inode i_{u,g}id initialization helpers
  fs: introduce fsuidgid_has_mapping() helper
  fs: document and rename fsid helpers
  fs: document mapping helpers
2021-04-27 12:49:42 -07:00
Miklos Szeredi
51db776a43 vfs: remove unused ioctl helpers
Remove vfs_ioc_setflags_prepare(), vfs_ioc_fssetxattr_check() and
simple_fill_fsxattr(), which are no longer used.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2021-04-12 15:04:30 +02:00
Christian Brauner
db998553cf
fs: introduce two inode i_{u,g}id initialization helpers
Give filesystem two little helpers that do the right thing when
initializing the i_uid and i_gid fields on idmapped and non-idmapped
mounts. Filesystems shouldn't have to be concerned with too many
details.

Link: https://lore.kernel.org/r/20210320122623.599086-5-christian.brauner@ubuntu.com
Inspired-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-03-23 11:15:26 +01:00
Christian Brauner
a65e58e791
fs: document and rename fsid helpers
Vivek pointed out that the fs{g,u}id_into_mnt() naming scheme can be
misleading as it could be understood as implying they do the exact same
thing as i_{g,u}id_into_mnt(). The original motivation for this naming
scheme was to signal to callers that the helpers will always take care
to map the k{g,u}id such that the ownership is expressed in terms of the
mnt_users.
Get rid of the confusion by renaming those helpers to something more
sensible. Al suggested mapped_fs{g,u}id() which seems a really good fit.
Usually filesystems don't need to bother with these helpers directly
only in some cases where they allocate objects that carry {g,u}ids which
are either filesystem specific (e.g. xfs quota objects) or don't have a
clean set of helpers as inodes have.

Link: https://lore.kernel.org/r/20210320122623.599086-3-christian.brauner@ubuntu.com
Inspired-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-03-23 11:13:32 +01:00
Linus Torvalds
5ceabb6078 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Assorted stuff pile - no common topic here"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  whack-a-mole: don't open-code iminor/imajor
  9p: fix misuse of sscanf() in v9fs_stat2inode()
  audit_alloc_mark(): don't open-code ERR_CAST()
  fs/inode.c: make inode_init_always() initialize i_ino to 0
  vfs: don't unnecessarily clone write access for writable fds
2021-02-27 08:07:12 -08:00
Linus Torvalds
7d6beb71da idmapped-mounts-v5.12
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Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull idmapped mounts from Christian Brauner:
 "This introduces idmapped mounts which has been in the making for some
  time. Simply put, different mounts can expose the same file or
  directory with different ownership. This initial implementation comes
  with ports for fat, ext4 and with Christoph's port for xfs with more
  filesystems being actively worked on by independent people and
  maintainers.

  Idmapping mounts handle a wide range of long standing use-cases. Here
  are just a few:

   - Idmapped mounts make it possible to easily share files between
     multiple users or multiple machines especially in complex
     scenarios. For example, idmapped mounts will be used in the
     implementation of portable home directories in
     systemd-homed.service(8) where they allow users to move their home
     directory to an external storage device and use it on multiple
     computers where they are assigned different uids and gids. This
     effectively makes it possible to assign random uids and gids at
     login time.

   - It is possible to share files from the host with unprivileged
     containers without having to change ownership permanently through
     chown(2).

   - It is possible to idmap a container's rootfs and without having to
     mangle every file. For example, Chromebooks use it to share the
     user's Download folder with their unprivileged containers in their
     Linux subsystem.

   - It is possible to share files between containers with
     non-overlapping idmappings.

   - Filesystem that lack a proper concept of ownership such as fat can
     use idmapped mounts to implement discretionary access (DAC)
     permission checking.

   - They allow users to efficiently changing ownership on a per-mount
     basis without having to (recursively) chown(2) all files. In
     contrast to chown (2) changing ownership of large sets of files is
     instantenous with idmapped mounts. This is especially useful when
     ownership of a whole root filesystem of a virtual machine or
     container is changed. With idmapped mounts a single syscall
     mount_setattr syscall will be sufficient to change the ownership of
     all files.

   - Idmapped mounts always take the current ownership into account as
     idmappings specify what a given uid or gid is supposed to be mapped
     to. This contrasts with the chown(2) syscall which cannot by itself
     take the current ownership of the files it changes into account. It
     simply changes the ownership to the specified uid and gid. This is
     especially problematic when recursively chown(2)ing a large set of
     files which is commong with the aforementioned portable home
     directory and container and vm scenario.

   - Idmapped mounts allow to change ownership locally, restricting it
     to specific mounts, and temporarily as the ownership changes only
     apply as long as the mount exists.

  Several userspace projects have either already put up patches and
  pull-requests for this feature or will do so should you decide to pull
  this:

   - systemd: In a wide variety of scenarios but especially right away
     in their implementation of portable home directories.

         https://systemd.io/HOME_DIRECTORY/

   - container runtimes: containerd, runC, LXD:To share data between
     host and unprivileged containers, unprivileged and privileged
     containers, etc. The pull request for idmapped mounts support in
     containerd, the default Kubernetes runtime is already up for quite
     a while now: https://github.com/containerd/containerd/pull/4734

   - The virtio-fs developers and several users have expressed interest
     in using this feature with virtual machines once virtio-fs is
     ported.

   - ChromeOS: Sharing host-directories with unprivileged containers.

  I've tightly synced with all those projects and all of those listed
  here have also expressed their need/desire for this feature on the
  mailing list. For more info on how people use this there's a bunch of
  talks about this too. Here's just two recent ones:

      https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf
      https://fosdem.org/2021/schedule/event/containers_idmap/

  This comes with an extensive xfstests suite covering both ext4 and
  xfs:

      https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts

  It covers truncation, creation, opening, xattrs, vfscaps, setid
  execution, setgid inheritance and more both with idmapped and
  non-idmapped mounts. It already helped to discover an unrelated xfs
  setgid inheritance bug which has since been fixed in mainline. It will
  be sent for inclusion with the xfstests project should you decide to
  merge this.

  In order to support per-mount idmappings vfsmounts are marked with
  user namespaces. The idmapping of the user namespace will be used to
  map the ids of vfs objects when they are accessed through that mount.
  By default all vfsmounts are marked with the initial user namespace.
  The initial user namespace is used to indicate that a mount is not
  idmapped. All operations behave as before and this is verified in the
  testsuite.

  Based on prior discussions we want to attach the whole user namespace
  and not just a dedicated idmapping struct. This allows us to reuse all
  the helpers that already exist for dealing with idmappings instead of
  introducing a whole new range of helpers. In addition, if we decide in
  the future that we are confident enough to enable unprivileged users
  to setup idmapped mounts the permission checking can take into account
  whether the caller is privileged in the user namespace the mount is
  currently marked with.

  The user namespace the mount will be marked with can be specified by
  passing a file descriptor refering to the user namespace as an
  argument to the new mount_setattr() syscall together with the new
  MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
  of extensibility.

  The following conditions must be met in order to create an idmapped
  mount:

   - The caller must currently have the CAP_SYS_ADMIN capability in the
     user namespace the underlying filesystem has been mounted in.

   - The underlying filesystem must support idmapped mounts.

   - The mount must not already be idmapped. This also implies that the
     idmapping of a mount cannot be altered once it has been idmapped.

   - The mount must be a detached/anonymous mount, i.e. it must have
     been created by calling open_tree() with the OPEN_TREE_CLONE flag
     and it must not already have been visible in the filesystem.

  The last two points guarantee easier semantics for userspace and the
  kernel and make the implementation significantly simpler.

  By default vfsmounts are marked with the initial user namespace and no
  behavioral or performance changes are observed.

  The manpage with a detailed description can be found here:

      1d7b902e28

  In order to support idmapped mounts, filesystems need to be changed
  and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
  patches to convert individual filesystem are not very large or
  complicated overall as can be seen from the included fat, ext4, and
  xfs ports. Patches for other filesystems are actively worked on and
  will be sent out separately. The xfstestsuite can be used to verify
  that port has been done correctly.

  The mount_setattr() syscall is motivated independent of the idmapped
  mounts patches and it's been around since July 2019. One of the most
  valuable features of the new mount api is the ability to perform
  mounts based on file descriptors only.

  Together with the lookup restrictions available in the openat2()
  RESOLVE_* flag namespace which we added in v5.6 this is the first time
  we are close to hardened and race-free (e.g. symlinks) mounting and
  path resolution.

  While userspace has started porting to the new mount api to mount
  proper filesystems and create new bind-mounts it is currently not
  possible to change mount options of an already existing bind mount in
  the new mount api since the mount_setattr() syscall is missing.

  With the addition of the mount_setattr() syscall we remove this last
  restriction and userspace can now fully port to the new mount api,
  covering every use-case the old mount api could. We also add the
  crucial ability to recursively change mount options for a whole mount
  tree, both removing and adding mount options at the same time. This
  syscall has been requested multiple times by various people and
  projects.

  There is a simple tool available at

      https://github.com/brauner/mount-idmapped

  that allows to create idmapped mounts so people can play with this
  patch series. I'll add support for the regular mount binary should you
  decide to pull this in the following weeks:

  Here's an example to a simple idmapped mount of another user's home
  directory:

	u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt

	u1001@f2-vm:/$ ls -al /home/ubuntu/
	total 28
	drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
	drwxr-xr-x 4 root   root   4096 Oct 28 04:00 ..
	-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
	-rw-r--r-- 1 ubuntu ubuntu  220 Feb 25  2020 .bash_logout
	-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25  2020 .bashrc
	-rw-r--r-- 1 ubuntu ubuntu  807 Feb 25  2020 .profile
	-rw-r--r-- 1 ubuntu ubuntu    0 Oct 16 16:11 .sudo_as_admin_successful
	-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo

	u1001@f2-vm:/$ ls -al /mnt/
	total 28
	drwxr-xr-x  2 u1001 u1001 4096 Oct 28 22:07 .
	drwxr-xr-x 29 root  root  4096 Oct 28 22:01 ..
	-rw-------  1 u1001 u1001 3154 Oct 28 22:12 .bash_history
	-rw-r--r--  1 u1001 u1001  220 Feb 25  2020 .bash_logout
	-rw-r--r--  1 u1001 u1001 3771 Feb 25  2020 .bashrc
	-rw-r--r--  1 u1001 u1001  807 Feb 25  2020 .profile
	-rw-r--r--  1 u1001 u1001    0 Oct 16 16:11 .sudo_as_admin_successful
	-rw-------  1 u1001 u1001 1144 Oct 28 00:43 .viminfo

	u1001@f2-vm:/$ touch /mnt/my-file

	u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file

	u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file

	u1001@f2-vm:/$ ls -al /mnt/my-file
	-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file

	u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
	-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file

	u1001@f2-vm:/$ getfacl /mnt/my-file
	getfacl: Removing leading '/' from absolute path names
	# file: mnt/my-file
	# owner: u1001
	# group: u1001
	user::rw-
	user:u1001:rwx
	group::rw-
	mask::rwx
	other::r--

	u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
	getfacl: Removing leading '/' from absolute path names
	# file: home/ubuntu/my-file
	# owner: ubuntu
	# group: ubuntu
	user::rw-
	user:ubuntu:rwx
	group::rw-
	mask::rwx
	other::r--"

* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
  xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
  xfs: support idmapped mounts
  ext4: support idmapped mounts
  fat: handle idmapped mounts
  tests: add mount_setattr() selftests
  fs: introduce MOUNT_ATTR_IDMAP
  fs: add mount_setattr()
  fs: add attr_flags_to_mnt_flags helper
  fs: split out functions to hold writers
  namespace: only take read lock in do_reconfigure_mnt()
  mount: make {lock,unlock}_mount_hash() static
  namespace: take lock_mount_hash() directly when changing flags
  nfs: do not export idmapped mounts
  overlayfs: do not mount on top of idmapped mounts
  ecryptfs: do not mount on top of idmapped mounts
  ima: handle idmapped mounts
  apparmor: handle idmapped mounts
  fs: make helpers idmap mount aware
  exec: handle idmapped mounts
  would_dump: handle idmapped mounts
  ...
2021-02-23 13:39:45 -08:00
Linus Torvalds
d61c6a58ae \n
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Merge tag 'lazytime_for_v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull lazytime updates from Jan Kara:
 "Cleanups of the lazytime handling in the writeback code making rules
  for calling ->dirty_inode() filesystem handlers saner"

* tag 'lazytime_for_v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  ext4: simplify i_state checks in __ext4_update_other_inode_time()
  gfs2: don't worry about I_DIRTY_TIME in gfs2_fsync()
  fs: improve comments for writeback_single_inode()
  fs: drop redundant check from __writeback_single_inode()
  fs: clean up __mark_inode_dirty() a bit
  fs: pass only I_DIRTY_INODE flags to ->dirty_inode
  fs: don't call ->dirty_inode for lazytime timestamp updates
  fat: only specify I_DIRTY_TIME when needed in fat_update_time()
  fs: only specify I_DIRTY_TIME when needed in generic_update_time()
  fs: correctly document the inode dirty flags
2021-02-22 13:17:39 -08:00
Christian Brauner
643fe55a06
open: handle idmapped mounts in do_truncate()
When truncating files the vfs will verify that the caller is privileged
over the inode. Extend it to handle idmapped mounts. If the inode is
accessed through an idmapped mount it is mapped according to the mount's
user namespace. Afterwards the permissions checks are identical to
non-idmapped mounts. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-16-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:18 +01:00
Christian Brauner
ba73d98745
namei: handle idmapped mounts in may_*() helpers
The may_follow_link(), may_linkat(), may_lookup(), may_open(),
may_o_create(), may_create_in_sticky(), may_delete(), and may_create()
helpers determine whether the caller is privileged enough to perform the
associated operations. Let them handle idmapped mounts by mapping the
inode or fsids according to the mount's user namespace. Afterwards the
checks are identical to non-idmapped inodes. The patch takes care to
retrieve the mount's user namespace right before performing permission
checks and passing it down into the fileystem so the user namespace
can't change in between by someone idmapping a mount that is currently
not idmapped. If the initial user namespace is passed nothing changes so
non-idmapped mounts will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-13-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:17 +01:00
Christian Brauner
2f221d6f7b
attr: handle idmapped mounts
When file attributes are changed most filesystems rely on the
setattr_prepare(), setattr_copy(), and notify_change() helpers for
initialization and permission checking. Let them handle idmapped mounts.
If the inode is accessed through an idmapped mount map it into the
mount's user namespace. Afterwards the checks are identical to
non-idmapped mounts. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.

Helpers that perform checks on the ia_uid and ia_gid fields in struct
iattr assume that ia_uid and ia_gid are intended values and have already
been mapped correctly at the userspace-kernelspace boundary as we
already do today. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-8-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:16 +01:00
Christian Brauner
21cb47be6f
inode: make init and permission helpers idmapped mount aware
The inode_owner_or_capable() helper determines whether the caller is the
owner of the inode or is capable with respect to that inode. Allow it to
handle idmapped mounts. If the inode is accessed through an idmapped
mount it according to the mount's user namespace. Afterwards the checks
are identical to non-idmapped mounts. If the initial user namespace is
passed nothing changes so non-idmapped mounts will see identical
behavior as before.

Similarly, allow the inode_init_owner() helper to handle idmapped
mounts. It initializes a new inode on idmapped mounts by mapping the
fsuid and fsgid of the caller from the mount's user namespace. If the
initial user namespace is passed nothing changes so non-idmapped mounts
will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-7-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:16 +01:00
Christian Brauner
0558c1bf5a
capability: handle idmapped mounts
In order to determine whether a caller holds privilege over a given
inode the capability framework exposes the two helpers
privileged_wrt_inode_uidgid() and capable_wrt_inode_uidgid(). The former
verifies that the inode has a mapping in the caller's user namespace and
the latter additionally verifies that the caller has the requested
capability in their current user namespace.
If the inode is accessed through an idmapped mount map it into the
mount's user namespace. Afterwards the checks are identical to
non-idmapped inodes. If the initial user namespace is passed all
operations are a nop so non-idmapped mounts will not see a change in
behavior.

Link: https://lore.kernel.org/r/20210121131959.646623-5-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:16 +01:00
Mauro Carvalho Chehab
961f3c898e fs: fix kernel-doc markups
Two markups are at the wrong place. Kernel-doc only
support having the comment just before the identifier.

Also, some identifiers have different names between their
prototypes and the kernel-doc markup.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/96b1e1b388600ab092331f6c4e88ff8e8779ce6c.1610610937.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-01-21 14:06:00 -07:00
Eric Biggers
e20b14db05 fs: only specify I_DIRTY_TIME when needed in generic_update_time()
generic_update_time() always passes I_DIRTY_TIME to
__mark_inode_dirty(), which doesn't really make sense because (a)
generic_update_time() might be asked to do only an i_version update, not
also a timestamps update; and (b) I_DIRTY_TIME is only supposed to be
set in i_state if the filesystem has lazytime enabled, so using it
unconditionally in generic_update_time() is inconsistent.

As a result there is a weird edge case where if only an i_version update
was requested (not also a timestamps update) but it is no longer needed
(i.e. inode_maybe_inc_iversion() returns false), then I_DIRTY_TIME will
be set in i_state even if the filesystem isn't mounted with lazytime.

Fix this by only passing I_DIRTY_TIME to __mark_inode_dirty() if the
timestamps were updated and the filesystem has lazytime enabled.

Link: https://lore.kernel.org/r/20210112190253.64307-4-ebiggers@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-01-13 17:26:28 +01:00
Eric Biggers
edbb35cc6b fs/inode.c: make inode_init_always() initialize i_ino to 0
Currently inode_init_always() doesn't initialize i_ino to 0.  This is
unexpected because unlike the other inode fields that aren't initialized
by inode_init_always(), i_ino isn't guaranteed to end up back at its
initial value after the inode is freed.  Only one filesystem (XFS)
actually sets set i_ino back to 0 when freeing its inodes.

So, callers of new_inode() see some random previous i_ino.  Normally
that's fine, since normally i_ino isn't accessed before being set.
There can be edge cases where that isn't necessarily true, though.

The one I've run into is that on ext4, when creating an encrypted file,
the new file's encryption key has to be set up prior to the jbd2
transaction, and thus prior to i_ino being set.  If something goes
wrong, fs/crypto/ may log warning or error messages, which normally
include i_ino.  So it needs to know whether it is valid to include i_ino
yet or not.  Also, on some files i_ino needs to be hashed for use in the
crypto, so fs/crypto/ needs to know whether that can be done yet or not.

There are ways this could be worked around, either in fs/crypto/ or in
fs/ext4/.  But, it seems there's no reason not to just fix
inode_init_always() to do the expected thing and initialize i_ino to 0.

So, do that, and also remove the initialization in jfs_fill_super() that
becomes redundant.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-01-04 14:10:32 -05:00
Linus Torvalds
7bb5226c8a Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Assorted patches from previous cycle(s)..."

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix hostfs_open() use of ->f_path.dentry
  Make sure that make_create_in_sticky() never sees uninitialized value of dir_mode
  fs: Kill DCACHE_DONTCACHE dentry even if DCACHE_REFERENCED is set
  fs: Handle I_DONTCACHE in iput_final() instead of generic_drop_inode()
  fs/namespace.c: WARN if mnt_count has become negative
2020-12-25 10:54:29 -08:00
Hao Li
88149082bb fs: Handle I_DONTCACHE in iput_final() instead of generic_drop_inode()
If generic_drop_inode() returns true, it means iput_final() can evict
this inode regardless of whether it is dirty or not. If we check
I_DONTCACHE in generic_drop_inode(), any inode with this bit set will be
evicted unconditionally. This is not the desired behavior because
I_DONTCACHE only means the inode shouldn't be cached on the LRU list.
As for whether we need to evict this inode, this is what
generic_drop_inode() should do. This patch corrects the usage of
I_DONTCACHE.

This patch was proposed in [1].

[1]: https://lore.kernel.org/linux-fsdevel/20200831003407.GE12096@dread.disaster.area/

Fixes: dae2f8ed79 ("fs: Lift XFS_IDONTCACHE to the VFS layer")
Signed-off-by: Hao Li <lihao2018.fnst@cn.fujitsu.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-12-10 17:33:17 -05:00
Christoph Hellwig
4e7b5671c6 block: remove i_bdev
Switch the block device lookup interfaces to directly work with a dev_t
so that struct block_device references are only acquired by the
blkdev_get variants (and the blk-cgroup special case).  This means that
we now don't need an extra reference in the inode and can generally
simplify handling of struct block_device to keep the lookups contained
in the core block layer code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Coly Li <colyli@suse.de>		[bcache]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:39 -07:00
Matthew Wilcox (Oracle)
01c7026705 fs: add a filesystem flag for THPs
The page cache needs to know whether the filesystem supports THPs so that
it doesn't send THPs to filesystems which can't handle them.  Dave Chinner
points out that getting from the page mapping to the filesystem type is
too many steps (mapping->host->i_sb->s_type->fs_flags) so cache that
information in the address space flags.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Link: https://lkml.kernel.org/r/20200916032717.22917-1-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16 11:11:15 -07:00
Linus Torvalds
9daa0a27a0 AFS Changes
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Merge tag 'afs-next-20200604' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull AFS updates from David Howells:
 "There's some core VFS changes which affect a couple of filesystems:

   - Make the inode hash table RCU safe and providing some RCU-safe
     accessor functions. The search can then be done without taking the
     inode_hash_lock. Care must be taken because the object may be being
     deleted and no wait is made.

   - Allow iunique() to avoid taking the inode_hash_lock.

   - Allow AFS's callback processing to avoid taking the inode_hash_lock
     when using the inode table to find an inode to notify.

   - Improve Ext4's time updating. Konstantin Khlebnikov said "For now,
     I've plugged this issue with try-lock in ext4 lazy time update.
     This solution is much better."

  Then there's a set of changes to make a number of improvements to the
  AFS driver:

   - Improve callback (ie. third party change notification) processing
     by:

      (a) Relying more on the fact we're doing this under RCU and by
          using fewer locks. This makes use of the RCU-based inode
          searching outlined above.

      (b) Moving to keeping volumes in a tree indexed by volume ID
          rather than a flat list.

      (c) Making the server and volume records logically part of the
          cell. This means that a server record now points directly at
          the cell and the tree of volumes is there. This removes an N:M
          mapping table, simplifying things.

   - Improve keeping NAT or firewall channels open for the server
     callbacks to reach the client by actively polling the fileserver on
     a timed basis, instead of only doing it when we have an operation
     to process.

   - Improving detection of delayed or lost callbacks by including the
     parent directory in the list of file IDs to be queried when doing a
     bulk status fetch from lookup. We can then check to see if our copy
     of the directory has changed under us without us getting notified.

   - Determine aliasing of cells (such as a cell that is pointed to be a
     DNS alias). This allows us to avoid having ambiguity due to
     apparently different cells using the same volume and file servers.

   - Improve the fileserver rotation to do more probing when it detects
     that all of the addresses to a server are listed as non-responsive.
     It's possible that an address that previously stopped responding
     has become responsive again.

  Beyond that, lay some foundations for making some calls asynchronous:

   - Turn the fileserver cursor struct into a general operation struct
     and hang the parameters off of that rather than keeping them in
     local variables and hang results off of that rather than the call
     struct.

   - Implement some general operation handling code and simplify the
     callers of operations that affect a volume or a volume component
     (such as a file). Most of the operation is now done by core code.

   - Operations are supplied with a table of operations to issue
     different variants of RPCs and to manage the completion, where all
     the required data is held in the operation object, thereby allowing
     these to be called from a workqueue.

   - Put the standard "if (begin), while(select), call op, end" sequence
     into a canned function that just emulates the current behaviour for
     now.

  There are also some fixes interspersed:

   - Don't let the EACCES from ICMP6 mapping reach the user as such,
     since it's confusing as to whether it's a filesystem error. Convert
     it to EHOSTUNREACH.

   - Don't use the epoch value acquired through probing a server. If we
     have two servers with the same UUID but in different cells, it's
     hard to draw conclusions from them having different epoch values.

   - Don't interpret the argument to the CB.ProbeUuid RPC as a
     fileserver UUID and look up a fileserver from it.

   - Deal with servers in different cells having the same UUIDs. In the
     event that a CB.InitCallBackState3 RPC is received, we have to
     break the callback promises for every server record matching that
     UUID.

   - Don't let afs_statfs return values that go below 0.

   - Don't use running fileserver probe state to make server selection
     and address selection decisions on. Only make decisions on final
     state as the running state is cleared at the start of probing"

Acked-by: Al Viro <viro@zeniv.linux.org.uk> (fs/inode.c part)

* tag 'afs-next-20200604' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (27 commits)
  afs: Adjust the fileserver rotation algorithm to reprobe/retry more quickly
  afs: Show more a bit more server state in /proc/net/afs/servers
  afs: Don't use probe running state to make decisions outside probe code
  afs: Fix afs_statfs() to not let the values go below zero
  afs: Fix the by-UUID server tree to allow servers with the same UUID
  afs: Reorganise volume and server trees to be rooted on the cell
  afs: Add a tracepoint to track the lifetime of the afs_volume struct
  afs: Detect cell aliases 3 - YFS Cells with a canonical cell name op
  afs: Detect cell aliases 2 - Cells with no root volumes
  afs: Detect cell aliases 1 - Cells with root volumes
  afs: Implement client support for the YFSVL.GetCellName RPC op
  afs: Retain more of the VLDB record for alias detection
  afs: Fix handling of CB.ProbeUuid cache manager op
  afs: Don't get epoch from a server because it may be ambiguous
  afs: Build an abstraction around an "operation" concept
  afs: Rename struct afs_fs_cursor to afs_operation
  afs: Remove the error argument from afs_protocol_error()
  afs: Set error flag rather than return error from file status decode
  afs: Make callback processing more efficient.
  afs: Show more information in /proc/net/afs/servers
  ...
2020-06-05 16:26:36 -07:00
Linus Torvalds
cb8e59cc87 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from David Miller:

 1) Allow setting bluetooth L2CAP modes via socket option, from Luiz
    Augusto von Dentz.

 2) Add GSO partial support to igc, from Sasha Neftin.

 3) Several cleanups and improvements to r8169 from Heiner Kallweit.

 4) Add IF_OPER_TESTING link state and use it when ethtool triggers a
    device self-test. From Andrew Lunn.

 5) Start moving away from custom driver versions, use the globally
    defined kernel version instead, from Leon Romanovsky.

 6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin.

 7) Allow hard IRQ deferral during NAPI, from Eric Dumazet.

 8) Add sriov and vf support to hinic, from Luo bin.

 9) Support Media Redundancy Protocol (MRP) in the bridging code, from
    Horatiu Vultur.

10) Support netmap in the nft_nat code, from Pablo Neira Ayuso.

11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina
    Dubroca. Also add ipv6 support for espintcp.

12) Lots of ReST conversions of the networking documentation, from Mauro
    Carvalho Chehab.

13) Support configuration of ethtool rxnfc flows in bcmgenet driver,
    from Doug Berger.

14) Allow to dump cgroup id and filter by it in inet_diag code, from
    Dmitry Yakunin.

15) Add infrastructure to export netlink attribute policies to
    userspace, from Johannes Berg.

16) Several optimizations to sch_fq scheduler, from Eric Dumazet.

17) Fallback to the default qdisc if qdisc init fails because otherwise
    a packet scheduler init failure will make a device inoperative. From
    Jesper Dangaard Brouer.

18) Several RISCV bpf jit optimizations, from Luke Nelson.

19) Correct the return type of the ->ndo_start_xmit() method in several
    drivers, it's netdev_tx_t but many drivers were using
    'int'. From Yunjian Wang.

20) Add an ethtool interface for PHY master/slave config, from Oleksij
    Rempel.

21) Add BPF iterators, from Yonghang Song.

22) Add cable test infrastructure, including ethool interfaces, from
    Andrew Lunn. Marvell PHY driver is the first to support this
    facility.

23) Remove zero-length arrays all over, from Gustavo A. R. Silva.

24) Calculate and maintain an explicit frame size in XDP, from Jesper
    Dangaard Brouer.

25) Add CAP_BPF, from Alexei Starovoitov.

26) Support terse dumps in the packet scheduler, from Vlad Buslov.

27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei.

28) Add devm_register_netdev(), from Bartosz Golaszewski.

29) Minimize qdisc resets, from Cong Wang.

30) Get rid of kernel_getsockopt and kernel_setsockopt in order to
    eliminate set_fs/get_fs calls. From Christoph Hellwig.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits)
  selftests: net: ip_defrag: ignore EPERM
  net_failover: fixed rollback in net_failover_open()
  Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv"
  Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"
  vmxnet3: allow rx flow hash ops only when rss is enabled
  hinic: add set_channels ethtool_ops support
  selftests/bpf: Add a default $(CXX) value
  tools/bpf: Don't use $(COMPILE.c)
  bpf, selftests: Use bpf_probe_read_kernel
  s390/bpf: Use bcr 0,%0 as tail call nop filler
  s390/bpf: Maintain 8-byte stack alignment
  selftests/bpf: Fix verifier test
  selftests/bpf: Fix sample_cnt shared between two threads
  bpf, selftests: Adapt cls_redirect to call csum_level helper
  bpf: Add csum_level helper for fixing up csum levels
  bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
  sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf()
  crypto/chtls: IPv6 support for inline TLS
  Crypto/chcr: Fixes a coccinile check error
  Crypto/chcr: Fixes compilations warnings
  ...
2020-06-03 16:27:18 -07:00
David Howells
3f19b2ab97 vfs, afs, ext4: Make the inode hash table RCU searchable
Make the inode hash table RCU searchable so that searches that want to
access or modify an inode without taking a ref on that inode can do so
without taking the inode hash table lock.

The main thing this requires is some RCU annotation on the list
manipulation operations.  Inodes are already freed by RCU in most cases.

Users of this interface must take care as the inode may be still under
construction or may be being torn down around them.

There are at least three instances where this can be of use:

 (1) Testing whether the inode number iunique() is going to return is
     currently unique (the iunique_lock is still held).

 (2) Ext4 date stamp updating.

 (3) AFS callback breaking.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
cc: linux-ext4@vger.kernel.org
cc: linux-afs@lists.infradead.org
2020-05-31 15:19:44 +01:00
Christoph Hellwig
32927393dc sysctl: pass kernel pointers to ->proc_handler
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from  userspace in common code.  This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-27 02:07:40 -04:00
Mauro Carvalho Chehab
2b8e8b5599 fs: inode.c: get rid of docs warnings
Use *foo makes the toolchain to think that this is an emphasis, causing
those warnings:

	./fs/inode.c:1609: WARNING: Inline emphasis start-string without end-string.
	./fs/inode.c:1609: WARNING: Inline emphasis start-string without end-string.
	./fs/inode.c:1615: WARNING: Inline emphasis start-string without end-string.

So, use, instead, ``*foo``, in order to mark it as a literal block.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/e8da46a0e57f2af6d63a0c53665495075698e28a.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-20 15:45:41 -06:00
Peter Zijlstra
8019ad13ef futex: Fix inode life-time issue
As reported by Jann, ihold() does not in fact guarantee inode
persistence. And instead of making it so, replace the usage of inode
pointers with a per boot, machine wide, unique inode identifier.

This sequence number is global, but shared (file backed) futexes are
rare enough that this should not become a performance issue.

Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2020-03-06 11:06:15 +01:00
Linus Torvalds
236f453294 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:

 - bmap series from cmaiolino

 - getting rid of convolutions in copy_mount_options() (use a couple of
   copy_from_user() instead of the __get_user() crap)

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  saner copy_mount_options()
  fibmap: Reject negative block numbers
  fibmap: Use bmap instead of ->bmap method in ioctl_fibmap
  ecryptfs: drop direct calls to ->bmap
  cachefiles: drop direct usage of ->bmap method.
  fs: Enable bmap() function to properly return errors
2020-02-08 13:04:49 -08:00
Linus Torvalds
bddea11b1b Merge branch 'imm.timestamp' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs timestamp updates from Al Viro:
 "More 64bit timestamp work"

* 'imm.timestamp' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  kernfs: don't bother with timestamp truncation
  fs: Do not overload update_time
  fs: Delete timespec64_trunc()
  fs: ubifs: Eliminate timespec64_trunc() usage
  fs: ceph: Delete timespec64_trunc() usage
  fs: cifs: Delete usage of timespec64_trunc
  fs: fat: Eliminate timespec64_trunc() usage
  utimes: Clamp the timestamps in notify_change()
2020-02-05 05:02:42 +00:00
Carlos Maiolino
30460e1ea3 fs: Enable bmap() function to properly return errors
By now, bmap() will either return the physical block number related to
the requested file offset or 0 in case of error or the requested offset
maps into a hole.
This patch makes the needed changes to enable bmap() to proper return
errors, using the return value as an error return, and now, a pointer
must be passed to bmap() to be filled with the mapped physical block.

It will change the behavior of bmap() on return:

- negative value in case of error
- zero on success or map fell into a hole

In case of a hole, the *block will be zero too

Since this is a prep patch, by now, the only error return is -EINVAL if
->bmap doesn't exist.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-03 08:05:37 -05:00
Daniel Rosenberg
6e1918cfb2 fscrypt: don't allow v1 policies with casefolding
Casefolded encrypted directories will use a new dirhash method that
requires a secret key.  If the directory uses a v2 encryption policy,
it's easy to derive this key from the master key using HKDF.  However,
v1 encryption policies don't provide a way to derive additional keys.

Therefore, don't allow casefolding on directories that use a v1 policy.
Specifically, make it so that trying to enable casefolding on a
directory that has a v1 policy fails, trying to set a v1 policy on a
casefolded directory fails, and trying to open a casefolded directory
that has a v1 policy (if one somehow exists on-disk) fails.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
[EB: improved commit message, updated fscrypt.rst, and other cleanups]
Link: https://lore.kernel.org/r/20200120223201.241390-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-01-22 14:47:15 -08:00
Eric Sandeen
04646aebd3 fs: avoid softlockups in s_inodes iterators
Anything that walks all inodes on sb->s_inodes list without rescheduling
risks softlockups.

Previous efforts were made in 2 functions, see:

c27d82f fs/drop_caches.c: avoid softlockups in drop_pagecache_sb()
ac05fbb inode: don't softlockup when evicting inodes

but there hasn't been an audit of all walkers, so do that now.  This
also consistently moves the cond_resched() calls to the bottom of each
loop in cases where it already exists.

One loop remains: remove_dquot_ref(), because I'm not quite sure how
to deal with that one w/o taking the i_lock.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-12-18 00:03:01 -05:00
Deepa Dinamani
23b424d9c3 fs: Do not overload update_time
update_time() also has an internal function pointer
update_time. Even though this works correctly, it is
confusing to the readers.

Just use a regular if statement to call the generic
function or the function pointer.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-12-08 19:10:56 -05:00
Deepa Dinamani
ba70609d5e fs: Delete timespec64_trunc()
There are no more callers to the function remaining.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-12-08 19:10:55 -05:00
Song Liu
09d91cda0e mm,thp: avoid writes to file with THP in pagecache
In previous patch, an application could put part of its text section in
THP via madvise().  These THPs will be protected from writes when the
application is still running (TXTBSY).  However, after the application
exits, the file is available for writes.

This patch avoids writes to file THP by dropping page cache for the file
when the file is open for write.  A new counter nr_thps is added to struct
address_space.  In do_dentry_open(), if the file is open for write and
nr_thps is non-zero, we drop page cache for the whole file.

Link: http://lkml.kernel.org/r/20190801184244.3169074-8-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Rik van Riel <riel@surriel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:11 -07:00
Deepa Dinamani
50e17c000c vfs: Add timestamp_truncate() api
timespec_trunc() function is used to truncate a
filesystem timestamp to the right granularity.
But, the function does not clamp tv_sec part of the
timestamps according to the filesystem timestamp limits.

The replacement api: timestamp_truncate() also alters the
signature of the function to accommodate filesystem
timestamp clamping according to flesystem limits.

Note that the tv_nsec part is set to 0 if tv_sec is not within
the range supported for the filesystem.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
2019-08-30 07:27:17 -07:00
Linus Torvalds
5010fe9f09 New for 5.3:
- Standardize parameter checking for the SETFLAGS and FSSETXATTR ioctls
   (which were the file attribute setters for ext4 and xfs and have now
   been hoisted to the vfs)
 - Only allow the DAX flag to be set on files and directories.
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Merge tag 'vfs-fix-ioctl-checking-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull common SETFLAGS/FSSETXATTR parameter checking from Darrick Wong:
 "Here's a patch series that sets up common parameter checking functions
  for the FS_IOC_SETFLAGS and FS_IOC_FSSETXATTR ioctl implementations.

  The goal here is to reduce the amount of behaviorial variance between
  the filesystems where those ioctls originated (ext2 and XFS,
  respectively) and everybody else.

   - Standardize parameter checking for the SETFLAGS and FSSETXATTR
     ioctls (which were the file attribute setters for ext4 and xfs and
     have now been hoisted to the vfs)

   - Only allow the DAX flag to be set on files and directories"

* tag 'vfs-fix-ioctl-checking-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  vfs: only allow FSSETXATTR to set DAX flag on files and dirs
  vfs: teach vfs_ioc_fssetxattr_check to check extent size hints
  vfs: teach vfs_ioc_fssetxattr_check to check project id info
  vfs: create a generic checking function for FS_IOC_FSSETXATTR
  vfs: create a generic checking and prep function for FS_IOC_SETFLAGS
2019-07-12 16:54:37 -07:00
Linus Torvalds
40f06c7995 Changes to copy_file_range for 5.3 from Dave and Amir:
- Create a generic copy_file_range handler and make individual
   filesystems responsible for calling it (i.e. no more assuming that
   do_splice_direct will work or is appropriate)
 - Refactor copy_file_range and remap_range parameter checking where they
   are the same
 - Install missing copy_file_range parameter checking(!)
 - Remove suid/sgid and update mtime like any other file write
 - Change the behavior so that a copy range crossing the source file's
   eof will result in a short copy to the source file's eof instead of
   EINVAL
 - Permit filesystems to decide if they want to handle cross-superblock
   copy_file_range in their local handlers.
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Merge tag 'copy-file-range-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull copy_file_range updates from Darrick Wong:
 "This fixes numerous parameter checking problems and inconsistent
  behaviors in the new(ish) copy_file_range system call.

  Now the system call will actually check its range parameters
  correctly; refuse to copy into files for which the caller does not
  have sufficient privileges; update mtime and strip setuid like file
  writes are supposed to do; and allows copying up to the EOF of the
  source file instead of failing the call like we used to.

  Summary:

   - Create a generic copy_file_range handler and make individual
     filesystems responsible for calling it (i.e. no more assuming that
     do_splice_direct will work or is appropriate)

   - Refactor copy_file_range and remap_range parameter checking where
     they are the same

   - Install missing copy_file_range parameter checking(!)

   - Remove suid/sgid and update mtime like any other file write

   - Change the behavior so that a copy range crossing the source file's
     eof will result in a short copy to the source file's eof instead of
     EINVAL

   - Permit filesystems to decide if they want to handle
     cross-superblock copy_file_range in their local handlers"

* tag 'copy-file-range-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  fuse: copy_file_range needs to strip setuid bits and update timestamps
  vfs: allow copy_file_range to copy across devices
  xfs: use file_modified() helper
  vfs: introduce file_modified() helper
  vfs: add missing checks to copy_file_range
  vfs: remove redundant checks from generic_remap_checks()
  vfs: introduce generic_file_rw_checks()
  vfs: no fallback for ->copy_file_range
  vfs: introduce generic_copy_file_range()
2019-07-10 20:32:37 -07:00
Darrick J. Wong
dbc77f31e5 vfs: only allow FSSETXATTR to set DAX flag on files and dirs
The DAX flag only applies to files and directories, so don't let it get
set for other types of files.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
2019-07-01 08:25:36 -07:00
Darrick J. Wong
ca29be7534 vfs: teach vfs_ioc_fssetxattr_check to check extent size hints
Move the extent size hint checks that aren't xfs-specific to the vfs.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
2019-07-01 08:25:36 -07:00
Darrick J. Wong
f991492ed1 vfs: teach vfs_ioc_fssetxattr_check to check project id info
Standardize the project id checks for FSSETXATTR.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
2019-07-01 08:25:35 -07:00
Darrick J. Wong
7b0e492e6b vfs: create a generic checking function for FS_IOC_FSSETXATTR
Create a generic checking function for the incoming FS_IOC_FSSETXATTR
fsxattr values so that we can standardize some of the implementation
behaviors.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
2019-07-01 08:25:35 -07:00
Darrick J. Wong
5aca284210 vfs: create a generic checking and prep function for FS_IOC_SETFLAGS
Create a generic function to check incoming FS_IOC_SETFLAGS flag values
and later prepare the inode for updates so that we can standardize the
implementations that follow ext4's flag values.

Note that the efivarfs implementation no longer fails a no-op SETFLAGS
without CAP_LINUX_IMMUTABLE since that's the behavior in ext*.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
2019-07-01 08:25:34 -07:00
Amir Goldstein
e38f7f53c3 vfs: introduce file_modified() helper
The combination of file_remove_privs() and file_update_mtime() is
quite common in filesystem ->write_iter() methods.

Modelled after the helper file_accessed(), introduce file_modified()
and use it from generic_remap_file_range_prep().

Note that the order of calling file_remove_privs() before
file_update_mtime() in the helper was matched to the more common order by
filesystems and not the current order in generic_remap_file_range_prep().

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-09 10:06:19 -07:00
Johannes Weiner
7b785645e8 mm: fix page cache convergence regression
Since a283348629 ("page cache: Finish XArray conversion"), on most
major Linux distributions, the page cache doesn't correctly transition
when the hot data set is changing, and leaves the new pages thrashing
indefinitely instead of kicking out the cold ones.

On a freshly booted, freshly ssh'd into virtual machine with 1G RAM
running stock Arch Linux:

[root@ham ~]# ./reclaimtest.sh
+ dd of=workingset-a bs=1M count=0 seek=600
+ cat workingset-a
+ cat workingset-a
+ cat workingset-a
+ cat workingset-a
+ cat workingset-a
+ cat workingset-a
+ cat workingset-a
+ cat workingset-a
+ ./mincore workingset-a
153600/153600 workingset-a
+ dd of=workingset-b bs=1M count=0 seek=600
+ cat workingset-b
+ cat workingset-b
+ cat workingset-b
+ cat workingset-b
+ ./mincore workingset-a workingset-b
104029/153600 workingset-a
120086/153600 workingset-b
+ cat workingset-b
+ cat workingset-b
+ cat workingset-b
+ cat workingset-b
+ ./mincore workingset-a workingset-b
104029/153600 workingset-a
120268/153600 workingset-b

workingset-b is a 600M file on a 1G host that is otherwise entirely
idle. No matter how often it's being accessed, it won't get cached.

While investigating, I noticed that the non-resident information gets
aggressively reclaimed - /proc/vmstat::workingset_nodereclaim. This is
a problem because a workingset transition like this relies on the
non-resident information tracked in the page cache tree of evicted
file ranges: when the cache faults are refaults of recently evicted
cache, we challenge the existing active set, and that allows a new
workingset to establish itself.

Tracing the shrinker that maintains this memory revealed that all page
cache tree nodes were allocated to the root cgroup. This is a problem,
because 1) the shrinker sizes the amount of non-resident information
it keeps to the size of the cgroup's other memory and 2) on most major
Linux distributions, only kernel threads live in the root cgroup and
everything else gets put into services or session groups:

[root@ham ~]# cat /proc/self/cgroup
0::/user.slice/user-0.slice/session-c1.scope

As a result, we basically maintain no non-resident information for the
workloads running on the system, thus breaking the caching algorithm.

Looking through the code, I found the culprit in the above-mentioned
patch: when switching from the radix tree to xarray, it dropped the
__GFP_ACCOUNT flag from the tree node allocations - the flag that
makes sure the allocated memory gets charged to and tracked by the
cgroup of the calling process - in this case, the one doing the fault.

To fix this, allow xarray users to specify per-tree flag that makes
xarray allocate nodes using __GFP_ACCOUNT. Then restore the page cache
tree annotation to request such cgroup tracking for the cache nodes.

With this patch applied, the page cache correctly converges on new
workingsets again after just a few iterations:

[root@ham ~]# ./reclaimtest.sh
+ dd of=workingset-a bs=1M count=0 seek=600
+ cat workingset-a
+ cat workingset-a
+ cat workingset-a
+ cat workingset-a
+ cat workingset-a
+ cat workingset-a
+ cat workingset-a
+ cat workingset-a
+ ./mincore workingset-a
153600/153600 workingset-a
+ dd of=workingset-b bs=1M count=0 seek=600
+ cat workingset-b
+ ./mincore workingset-a workingset-b
124607/153600 workingset-a
87876/153600 workingset-b
+ cat workingset-b
+ ./mincore workingset-a workingset-b
81313/153600 workingset-a
133321/153600 workingset-b
+ cat workingset-b
+ ./mincore workingset-a workingset-b
63036/153600 workingset-a
153600/153600 workingset-b

Cc: stable@vger.kernel.org # 4.20+
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2019-05-31 13:52:41 -04:00
Thomas Gleixner
457c899653 treewide: Add SPDX license identifier for missed files
Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
   initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:45 +02:00
Linus Torvalds
149e703cb8 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Assorted stuff, with no common topic whatsoever..."

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  libfs: document simple_get_link()
  Documentation/filesystems/Locking: fix ->get_link() prototype
  Documentation/filesystems/vfs.txt: document how ->i_link works
  Documentation/filesystems/vfs.txt: remove bogus "Last updated" date
  fs: use timespec64 in relatime_need_update
  fs/block_dev.c: remove unused include
2019-05-07 20:50:27 -07:00
Linus Torvalds
168e153d5e Merge branch 'work.icache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs inode freeing updates from Al Viro:
 "Introduction of separate method for RCU-delayed part of
  ->destroy_inode() (if any).

  Pretty much as posted, except that destroy_inode() stashes
  ->free_inode into the victim (anon-unioned with ->i_fops) before
  scheduling i_callback() and the last two patches (sockfs conversion
  and folding struct socket_wq into struct socket) are excluded - that
  pair should go through netdev once davem reopens his tree"

* 'work.icache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (58 commits)
  orangefs: make use of ->free_inode()
  shmem: make use of ->free_inode()
  hugetlb: make use of ->free_inode()
  overlayfs: make use of ->free_inode()
  jfs: switch to ->free_inode()
  fuse: switch to ->free_inode()
  ext4: make use of ->free_inode()
  ecryptfs: make use of ->free_inode()
  ceph: use ->free_inode()
  btrfs: use ->free_inode()
  afs: switch to use of ->free_inode()
  dax: make use of ->free_inode()
  ntfs: switch to ->free_inode()
  securityfs: switch to ->free_inode()
  apparmor: switch to ->free_inode()
  rpcpipe: switch to ->free_inode()
  bpf: switch to ->free_inode()
  mqueue: switch to ->free_inode()
  ufs: switch to ->free_inode()
  coda: switch to ->free_inode()
  ...
2019-05-07 10:57:05 -07:00
Al Viro
fdb0da89f4 new inode method: ->free_inode()
A lot of ->destroy_inode() instances end with call_rcu() of a callback
that does RCU-delayed part of freeing.  Introduce a new method for
doing just that, with saner signature.

Rules:
->destroy_inode		->free_inode
	f			g		immediate call of f(),
						RCU-delayed call of g()
	f			NULL		immediate call of f(),
						no RCU-delayed calls
	NULL			g		RCU-delayed call of g()
	NULL			NULL		RCU-delayed default freeing

IOW, NULL ->free_inode gives the same behaviour as now.

Note that NULL, NULL is equivalent to NULL, free_inode_nonrcu; we could
mandate the latter form, but that would have very little benefit beyond
making rules a bit more symmetric.  It would break backwards compatibility,
require extra boilerplate and expected semantics for (NULL, NULL) pair
would have no use whatsoever...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-01 22:37:39 -04:00
Alexander Lochmann
f69e749a49 Abort file_remove_privs() for non-reg. files
file_remove_privs() might be called for non-regular files, e.g.
blkdev inode. There is no reason to do its job on things
like blkdev inodes, pipes, or cdevs. Hence, abort if
file does not refer to a regular inode.

AV: more to the point, for devices there might be any number of
inodes refering to given device.  Which one to strip the permissions
from, even if that made any sense in the first place?  All of them
will be observed with contents modified, after all.

Found by LockDoc (Alexander Lochmann, Horst Schirmeier and Olaf
Spinczyk)

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Alexander Lochmann <alexander.lochmann@tu-dortmund.de>
Signed-off-by: Horst Schirmeier <horst.schirmeier@tu-dortmund.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-28 21:46:57 -04:00
Arnd Bergmann
6f22b6649e fs: use timespec64 in relatime_need_update
For some reason, the conversion of the VFS code away from 'struct timespec'
left one function behind that still uses it, for absolutely no reason.

Using timespec64 will make the atime update logic work correctly past
y2038.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-26 11:18:38 -04:00
Vineet Gupta
a905737fdd fs/inode.c: inode_set_flags(): replace opencoded set_mask_bits()
It seems that commits 5f16f3225b and 00a1a053eb, both with same
commitlog ("ext4: atomically set inode->i_flags in ext4_set_inode_flags()")
introduced the set_mask_bits API, but somehow missed not using it in ext4
in the end.

Also, set_mask_bits() is used in fs quite a bit and we can possibly come
up with a generic llsc based implementation (w/o the cmpxchg loop)

Link: http://lkml.kernel.org/r/1548275584-18096-3-git-send-email-vgupta@synopsys.com
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reviewed-by: Anthony Yznaga <anthony.yznaga@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-05 21:07:13 -08:00
Dave Chinner
69056ee6a8 Revert "mm: don't reclaim inodes with many attached pages"
This reverts commit a76cf1a474 ("mm: don't reclaim inodes with many
attached pages").

This change causes serious changes to page cache and inode cache
behaviour and balance, resulting in major performance regressions when
combining worklaods such as large file copies and kernel compiles.

  https://bugzilla.kernel.org/show_bug.cgi?id=202441

This change is a hack to work around the problems introduced by changing
how agressive shrinkers are on small caches in commit 172b06c32b ("mm:
slowly shrink slabs with a relatively small number of objects").  It
creates more problems than it solves, wasn't adequately reviewed or
tested, so it needs to be reverted.

Link: http://lkml.kernel.org/r/20190130041707.27750-2-david@fromorbit.com
Fixes: a76cf1a474 ("mm: don't reclaim inodes with many attached pages")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Cc: Wolfgang Walter <linux@stwm.de>
Cc: Roman Gushchin <guro@fb.com>
Cc: Spock <dairinin@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-12 16:33:18 -08:00
Linus Torvalds
b12a9124ee y2038: more syscalls and cleanups
This concludes the main part of the system call rework for 64-bit time_t,
 which has spread over most of year 2018, the last six system calls being
 
  - ppoll
  - pselect6
  - io_pgetevents
  - recvmmsg
  - futex
  - rt_sigtimedwait
 
 As before, nothing changes for 64-bit architectures, while 32-bit
 architectures gain another entry point that differs only in the layout
 of the timespec structure. Hopefully in the next release we can wire up
 all 22 of those system calls on all 32-bit architectures, which gives
 us a baseline version for glibc to start using them.
 
 This does not include the clock_adjtime, getrusage/waitid, and
 getitimer/setitimer system calls. I still plan to have new versions
 of those as well, but they are not required for correct operation of
 the C library since they can be emulated using the old 32-bit time_t
 based system calls.
 
 Aside from the system calls, there are also a few cleanups here,
 removing old kernel internal interfaces that have become unused after
 all references got removed. The arch/sh cleanups are part of this,
 there were posted several times over the past year without a reaction
 from the maintainers, while the corresponding changes made it into all
 other architectures.
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Merge tag 'y2038-for-4.21' of ssh://gitolite.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

Pull y2038 updates from Arnd Bergmann:
 "More syscalls and cleanups

  This concludes the main part of the system call rework for 64-bit
  time_t, which has spread over most of year 2018, the last six system
  calls being

    - ppoll
    - pselect6
    - io_pgetevents
    - recvmmsg
    - futex
    - rt_sigtimedwait

  As before, nothing changes for 64-bit architectures, while 32-bit
  architectures gain another entry point that differs only in the layout
  of the timespec structure. Hopefully in the next release we can wire
  up all 22 of those system calls on all 32-bit architectures, which
  gives us a baseline version for glibc to start using them.

  This does not include the clock_adjtime, getrusage/waitid, and
  getitimer/setitimer system calls. I still plan to have new versions of
  those as well, but they are not required for correct operation of the
  C library since they can be emulated using the old 32-bit time_t based
  system calls.

  Aside from the system calls, there are also a few cleanups here,
  removing old kernel internal interfaces that have become unused after
  all references got removed. The arch/sh cleanups are part of this,
  there were posted several times over the past year without a reaction
  from the maintainers, while the corresponding changes made it into all
  other architectures"

* tag 'y2038-for-4.21' of ssh://gitolite.kernel.org:/pub/scm/linux/kernel/git/arnd/playground:
  timekeeping: remove obsolete time accessors
  vfs: replace current_kernel_time64 with ktime equivalent
  timekeeping: remove timespec_add/timespec_del
  timekeeping: remove unused {read,update}_persistent_clock
  sh: remove board_time_init() callback
  sh: remove unused rtc_sh_get/set_time infrastructure
  sh: sh03: rtc: push down rtc class ops into driver
  sh: dreamcast: rtc: push down rtc class ops into driver
  y2038: signal: Add compat_sys_rt_sigtimedwait_time64
  y2038: signal: Add sys_rt_sigtimedwait_time32
  y2038: socket: Add compat_sys_recvmmsg_time64
  y2038: futex: Add support for __kernel_timespec
  y2038: futex: Move compat implementation into futex.c
  io_pgetevents: use __kernel_timespec
  pselect6: use __kernel_timespec
  ppoll: use __kernel_timespec
  signal: Add restore_user_sigmask()
  signal: Add set_user_sigmask()
2018-12-28 12:45:04 -08:00
Arnd Bergmann
d651d1607f vfs: replace current_kernel_time64 with ktime equivalent
current_time is the last remaining caller of current_kernel_time64(),
which is a wrapper around ktime_get_coarse_real_ts64().  This calls the
latter directly for consistency with the rest of the kernel that is moving
to the ktime_get_ family of time accessors, as now documented in
Documentation/core-api/timekeeping.rst.

An open questions is whether we may want to actually call the more
accurate ktime_get_real_ts64() for file systems that save high-resolution
timestamps in their on-disk format.  This would add a small overhead to
each update of the inode stamps but lead to inode timestamps to actually
have a usable resolution better than one jiffy (1 to 10 milliseconds
normally).  Experiments on a variety of hardware platforms show a typical
time of around 100 CPU cycles to read the cycle counter and calculate the
accurate time from that.  On old platforms without a cycle counter, this
can be signiciantly higher, up to several microseconds to access a
hardware clock, but those have become very rare by now.

I traced the original addition of the current_kernel_time() call to set
the nanosecond fields back to linux-2.5.48, where Andi Kleen added a patch
with subject "nanosecond stat timefields".  Andi explains that the
motivation was to introduce as little overhead as possible back then.  At
this time, reading the clock hardware was also more expensive when most
architectures did not have a cycle counter.

One side effect of having more accurate inode timestamp would be having to
write out the inode every time that mtime/ctime/atime get touched on most
systems, whereas many file systems today only write it when the timestamps
have changed, i.e.  at most once per jiffy unless something else changes
as well.  That change would certainly be noticed in some workloads, which
is enough reason to not do it without a good reason, regardless of the
cost of reading the time.

One thing we could still consider however would be to round the timestamps
from current_time() to multiples of NSEC_PER_JIFFY, e.g.  full
milliseconds rather than having six or seven meaningless but confusing
digits at the end of the timestamp.

Link: http://lkml.kernel.org/r/20180726130820.4174359-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-12-18 16:13:05 +01:00
Roman Gushchin
a76cf1a474 mm: don't reclaim inodes with many attached pages
Spock reported that commit 172b06c32b ("mm: slowly shrink slabs with a
relatively small number of objects") leads to a regression on his setup:
periodically the majority of the pagecache is evicted without an obvious
reason, while before the change the amount of free memory was balancing
around the watermark.

The reason behind is that the mentioned above change created some
minimal background pressure on the inode cache.  The problem is that if
an inode is considered to be reclaimed, all belonging pagecache page are
stripped, no matter how many of them are there.  So, if a huge
multi-gigabyte file is cached in the memory, and the goal is to reclaim
only few slab objects (unused inodes), we still can eventually evict all
gigabytes of the pagecache at once.

The workload described by Spock has few large non-mapped files in the
pagecache, so it's especially noticeable.

To solve the problem let's postpone the reclaim of inodes, which have
more than 1 attached page.  Let's wait until the pagecache pages will be
evicted naturally by scanning the corresponding LRU lists, and only then
reclaim the inode structure.

Link: http://lkml.kernel.org/r/20181023164302.20436-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Reported-by: Spock <dairinin@gmail.com>
Tested-by: Spock <dairinin@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: <stable@vger.kernel.org>	[4.19.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-18 10:15:09 -08:00
Mike Rapoport
57c8a661d9 mm: remove include/linux/bootmem.h
Move remaining definitions and declarations from include/linux/bootmem.h
into include/linux/memblock.h and remove the redundant header.

The includes were replaced with the semantic patch below and then
semi-automated removal of duplicated '#include <linux/memblock.h>

@@
@@
- #include <linux/bootmem.h>
+ #include <linux/memblock.h>

[sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h]
  Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au
[sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h]
  Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au
[sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal]
  Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au
Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-31 08:54:16 -07:00
Matthew Wilcox
a283348629 page cache: Finish XArray conversion
With no more radix tree API users left, we can drop the GFP flags
and use xa_init() instead of INIT_RADIX_TREE().

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:44 -04:00
Linus Torvalds
d9a185f8b4 overlayfs update for 4.19
This contains two new features:
 
  1) Stack file operations: this allows removal of several hacks from the
     VFS, proper interaction of read-only open files with copy-up,
     possibility to implement fs modifying ioctls properly, and others.
 
  2) Metadata only copy-up: when file is on lower layer and only metadata is
     modified (except size) then only copy up the metadata and continue to
     use the data from the lower file.
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Merge tag 'ovl-update-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs updates from Miklos Szeredi:
 "This contains two new features:

   - Stack file operations: this allows removal of several hacks from
     the VFS, proper interaction of read-only open files with copy-up,
     possibility to implement fs modifying ioctls properly, and others.

   - Metadata only copy-up: when file is on lower layer and only
     metadata is modified (except size) then only copy up the metadata
     and continue to use the data from the lower file"

* tag 'ovl-update-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (66 commits)
  ovl: Enable metadata only feature
  ovl: Do not do metacopy only for ioctl modifying file attr
  ovl: Do not do metadata only copy-up for truncate operation
  ovl: add helper to force data copy-up
  ovl: Check redirect on index as well
  ovl: Set redirect on upper inode when it is linked
  ovl: Set redirect on metacopy files upon rename
  ovl: Do not set dentry type ORIGIN for broken hardlinks
  ovl: Add an inode flag OVL_CONST_INO
  ovl: Treat metacopy dentries as type OVL_PATH_MERGE
  ovl: Check redirects for metacopy files
  ovl: Move some dir related ovl_lookup_single() code in else block
  ovl: Do not expose metacopy only dentry from d_real()
  ovl: Open file with data except for the case of fsync
  ovl: Add helper ovl_inode_realdata()
  ovl: Store lower data inode in ovl_inode
  ovl: Fix ovl_getattr() to get number of blocks from lower
  ovl: Add helper ovl_dentry_lowerdata() to get lower data dentry
  ovl: Copy up meta inode data from lowest data inode
  ovl: Modify ovl_lookup() and friends to lookup metacopy dentry
  ...
2018-08-21 18:19:09 -07:00
Linus Torvalds
0ea97a2d61 Merge branch 'work.mkdir' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs icache updates from Al Viro:

 - NFS mkdir/open_by_handle race fix

 - analogous solution for FUSE, replacing the one currently in mainline

 - new primitive to be used when discarding halfway set up inodes on
   failed object creation; gives sane warranties re icache lookups not
   returning such doomed by still not freed inodes. A bunch of
   filesystems switched to that animal.

 - Miklos' fix for last cycle regression in iget5_locked(); -stable will
   need a slightly different variant, unfortunately.

 - misc bits and pieces around things icache-related (in adfs and jfs).

* 'work.mkdir' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  jfs: don't bother with make_bad_inode() in ialloc()
  adfs: don't put inodes into icache
  new helper: inode_fake_hash()
  vfs: don't evict uninitialized inode
  jfs: switch to discard_new_inode()
  ext2: make sure that partially set up inodes won't be returned by ext2_iget()
  udf: switch to discard_new_inode()
  ufs: switch to discard_new_inode()
  btrfs: switch to discard_new_inode()
  new primitive: discard_new_inode()
  kill d_instantiate_no_diralias()
  nfs_instantiate(): prevent multiple aliases for directory inode
2018-08-13 20:25:58 -07:00
Miklos Szeredi
e950564b97 vfs: don't evict uninitialized inode
iput() ends up calling ->evict() on new inode, which is not yet initialized
by owning fs.  So use destroy_inode() instead.

Add to sb->s_inodes list only if inode is not in I_CREATING state (meaning
that it wasn't allocated with new_inode(), which already does the
insertion).

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 80ea09a002 ("vfs: factor out inode_insert5()")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-08-03 16:03:32 -04:00
Al Viro
c2b6d621c4 new primitive: discard_new_inode()
We don't want open-by-handle picking half-set-up in-core
struct inode from e.g. mkdir() having failed halfway through.
In other words, we don't want such inodes returned by iget_locked()
on their way to extinction.  However, we can't just have them
unhashed - otherwise open-by-handle immediately *after* that would've
ended up creating a new in-core inode over the on-disk one that
is in process of being freed right under us.

	Solution: new flag (I_CREATING) set by insert_inode_locked() and
removed by unlock_new_inode() and a new primitive (discard_new_inode())
to be used by such halfway-through-setup failure exits instead of
unlock_new_inode() / iput() combinations.  That primitive unlocks new
inode, but leaves I_CREATING in place.

	iget_locked() treats finding an I_CREATING inode as failure
(-ESTALE, once we sort out the error propagation).
	insert_inode_locked() treats the same as instant -EBUSY.
	ilookup() treats those as icache miss.

[Fix by Dan Carpenter <dan.carpenter@oracle.com> folded in]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-08-03 15:55:30 -04:00
Miklos Szeredi
c671854346 Revert "vfs: update ovl inode before relatime check"
This reverts commit 598e3c8f72.

Overlayfs no longer relies on the vfs correct atime handling.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-18 15:44:43 +02:00
Miklos Szeredi
88059de155 Revert "ovl: fix relatime for directories"
This reverts commit cd91304e71.

Overlayfs no longer relies on the vfs correct atime handling.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-18 15:44:43 +02:00
Linus Torvalds
0fa3ecd878 Fix up non-directory creation in SGID directories
sgid directories have special semantics, making newly created files in
the directory belong to the group of the directory, and newly created
subdirectories will also become sgid.  This is historically used for
group-shared directories.

But group directories writable by non-group members should not imply
that such non-group members can magically join the group, so make sure
to clear the sgid bit on non-directories for non-members (but remember
that sgid without group execute means "mandatory locking", just to
confuse things even more).

Reported-by: Jann Horn <jannh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-05 12:36:36 -07:00
Linus Torvalds
7a932516f5 vfs/y2038: inode timestamps conversion to timespec64
This is a late set of changes from Deepa Dinamani doing an automated
 treewide conversion of the inode and iattr structures from 'timespec'
 to 'timespec64', to push the conversion from the VFS layer into the
 individual file systems.
 
 There were no conflicts between this and the contents of linux-next
 until just before the merge window, when we saw multiple problems:
 
 - A minor conflict with my own y2038 fixes, which I could address
   by adding another patch on top here.
 - One semantic conflict with late changes to the NFS tree. I addressed
   this by merging Deepa's original branch on top of the changes that
   now got merged into mainline and making sure the merge commit includes
   the necessary changes as produced by coccinelle.
 - A trivial conflict against the removal of staging/lustre.
 - Multiple conflicts against the VFS changes in the overlayfs tree.
   These are still part of linux-next, but apparently this is no longer
   intended for 4.18 [1], so I am ignoring that part.
 
 As Deepa writes:
 
   The series aims to switch vfs timestamps to use struct timespec64.
   Currently vfs uses struct timespec, which is not y2038 safe.
 
   The series involves the following:
   1. Add vfs helper functions for supporting struct timepec64 timestamps.
   2. Cast prints of vfs timestamps to avoid warnings after the switch.
   3. Simplify code using vfs timestamps so that the actual
      replacement becomes easy.
   4. Convert vfs timestamps to use struct timespec64 using a script.
      This is a flag day patch.
 
   Next steps:
   1. Convert APIs that can handle timespec64, instead of converting
      timestamps at the boundaries.
   2. Update internal data structures to avoid timestamp conversions.
 
 Thomas Gleixner adds:
 
   I think there is no point to drag that out for the next merge window.
   The whole thing needs to be done in one go for the core changes which
   means that you're going to play that catchup game forever. Let's get
   over with it towards the end of the merge window.
 
 [1] https://www.spinics.net/lists/linux-fsdevel/msg128294.html
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Merge tag 'vfs-timespec64' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground

Pull inode timestamps conversion to timespec64 from Arnd Bergmann:
 "This is a late set of changes from Deepa Dinamani doing an automated
  treewide conversion of the inode and iattr structures from 'timespec'
  to 'timespec64', to push the conversion from the VFS layer into the
  individual file systems.

  As Deepa writes:

   'The series aims to switch vfs timestamps to use struct timespec64.
    Currently vfs uses struct timespec, which is not y2038 safe.

    The series involves the following:
    1. Add vfs helper functions for supporting struct timepec64
       timestamps.
    2. Cast prints of vfs timestamps to avoid warnings after the switch.
    3. Simplify code using vfs timestamps so that the actual replacement
       becomes easy.
    4. Convert vfs timestamps to use struct timespec64 using a script.
       This is a flag day patch.

    Next steps:
    1. Convert APIs that can handle timespec64, instead of converting
       timestamps at the boundaries.
    2. Update internal data structures to avoid timestamp conversions'

  Thomas Gleixner adds:

   'I think there is no point to drag that out for the next merge
    window. The whole thing needs to be done in one go for the core
    changes which means that you're going to play that catchup game
    forever. Let's get over with it towards the end of the merge window'"

* tag 'vfs-timespec64' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground:
  pstore: Remove bogus format string definition
  vfs: change inode times to use struct timespec64
  pstore: Convert internal records to timespec64
  udf: Simplify calls to udf_disk_stamp_to_time
  fs: nfs: get rid of memcpys for inode times
  ceph: make inode time prints to be long long
  lustre: Use long long type to print inode time
  fs: add timespec64_truncate()
2018-06-15 07:31:07 +09:00