51787 Commits

Author SHA1 Message Date
Darrick J. Wong
a605e86912 xfs: fix btree scrub deref check
The btree scrubber has some custom code to retrieve and check a btree
block via xfs_btree_lookup_get_block.  This function will either return
an error code (verifiers failed) or a *pblock will be untouched (bad
pointer).  Since we previously set *pblock to NULL, we need to check
*pblock, not pblock, to trigger the early bailout.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-11-09 09:10:45 -08:00
Darrick J. Wong
72f76f7364 xfs: fix uninitialized return values in scrub code
Fix smatch complaints about uninitialized return codes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-11-09 09:10:45 -08:00
Darrick J. Wong
0a1e1567b3 xfs: pass inode number to xfs_scrub_ino_set_{preen,warning}
There are two ways to scrub an inode -- calling xfs_iget and checking
the raw inode core, or by loading the inode cluster buffer and checking
the on-disk contents directly.  The second method is only useful if
_iget fails the verifiers; when this is the case, sc->ip is NULL and
calling the tracepoint will cause a system crash.

Therefore, pass the raw inode number directly into the _preen and
_warning functions.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-11-09 09:10:45 -08:00
Darrick J. Wong
35ce852334 xfs: refactor the directory data block bestfree checks
In a directory data block, the zeroth bestfree item must point to the
longest free space.  Therefore, when we check the bestfree block's
records against the data blocks, we only need to compare with bf[0] and
don't need the loop.

The weird loop was most probably the result of an earlier refactoring
gone bad.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-11-09 09:10:45 -08:00
Miklos Szeredi
95e6d4177c ovl: grab reference to workbasedir early
and related cleanups.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:29 +01:00
Miklos Szeredi
f7e3a7d947 ovl: split out ovl_get_indexdir() from ovl_fill_super()
It's okay to get rid of the intermediate error label due to ufs being
zeroed on allocation.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:28 +01:00
Miklos Szeredi
c0d91fb910 ovl: split out ovl_get_lower_layers() from ovl_fill_super()
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:28 +01:00
Miklos Szeredi
8ed61dc37e ovl: split out ovl_get_workdir() from ovl_fill_super()
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:28 +01:00
Miklos Szeredi
21a3b317a6 ovl: split out ovl_get_upper() from ovl_fill_super()
And don't clobber ufs->upper_mnt on error.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:28 +01:00
Miklos Szeredi
53dbb0b478 ovl: split out ovl_get_lowerstack() from ovl_fill_super()
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:28 +01:00
Miklos Szeredi
87ad447a9d ovl: split out ovl_get_workpath() from ovl_fill_super()
It's okay to get rid of the intermediate error label due to ufs being
zeroed on allocation.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:28 +01:00
Miklos Szeredi
6ee8acf0f7 ovl: split out ovl_get_upperpath() from ovl_fill_super()
It's okay to get rid of the intermediate error label due to ufs being
zeroed on allocation.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:28 +01:00
Miklos Szeredi
8aafcb593d ovl: use path_put_init() in error paths for ovl_fill_super()
This allows simplifying the error cleanup later.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:28 +01:00
Amir Goldstein
f30536f0f9 ovl: update cache version of impure parent on rename
ovl_rename() updates dir cache version for impure old parent if an entry
with copy up origin is moved into old parent, but it did not update
cache version if the entry moved out of old parent has a copy up origin.

[SzM] Same for new dir: we updated the version if an entry with origin was
moved in, but not if an entry with origin was moved out.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:27 +01:00
Amir Goldstein
a0c5ad307a ovl: relax same fs constraint for constant st_ino
For the case of all layers not on the same fs, return the copy up origin
inode st_dev/st_ino for non-dir from stat(2).

This guaranties constant st_dev/st_ino for non-dir across copy up.
Like the same fs case, st_ino of non-dir is also persistent.

If the st_dev/st_ino for copied up object would have been the same as
that of the real underlying lower file, running diff on underlying lower
file and overlay copied up file would result in diff reporting that the
two files are equal when in fact, they may have different content.

Therefore, unlike the same fs case, st_dev is not persistent because it
uses the unique anonymous bdev allocated for the lower layer.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:27 +01:00
Chandan Rajendra
ba1e563cdc ovl: return anonymous st_dev for lower inodes
For non-samefs setup, to make sure that st_dev/st_ino pair is unique
across the system, we return a unique anonymous st_dev for stat(2)
of lower layer inode.

A following patch is going to fix constant st_dev/st_ino across copy up
by returning origin st_dev/st_ino for copied up objects.

If the st_dev/st_ino for copied up object would have been the same as
that of the real underlying lower file, running diff on underlying lower
file and overlay copied up file would result in diff reporting that the
2 files are equal when in fact, they may have different content.

[amir: simplify ovl_get_pseudo_dev()
       split from allocate anonymous bdev patch]

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:27 +01:00
Chandan Rajendra
2a9c6d066e ovl: allocate anonymous devs for lowerdirs
Generate unique values of st_dev per lower layer for non-samefs
overlay mount. The unique values are obtained by allocating anonymous
bdevs for each of the lowerdirs in the overlayfs instance.

The anonymous bdev is going to be returned by stat(2) for lowerdir
non-dir entries in non-samefs case.

[amir: split from ovl_getattr() and re-structure patches]

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:27 +01:00
Chandan Rajendra
b93436320c ovl: re-structure overlay lower layers in-memory
Define new structures to represent overlay instance lower layers and
overlay merge dir lower layers to make room for storing more per layer
information in-memory.

Instead of keeping the fs instance lower layers in an array of struct
vfsmount, keep them in an array of new struct ovl_layer, that has a
pointer to struct vfsmount.

Instead of keeping the dentry lower layers in an array of struct path,
keep them in an array of new struct ovl_path, that has a pointer to
struct dentry and to struct ovl_layer.

Add a small helper to find the fs layer id that correspopnds to a lower
struct ovl_path and use it in ovl_lookup().

[amir: split re-structure from anonymous bdev patch]

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:27 +01:00
Amir Goldstein
ee023c30d7 ovl: move include of ovl_entry.h into overlayfs.h
Most overlayfs c files already explicitly include ovl_entry.h
to use overlay entry struct definitions and upcoming changes
are going to require even more c files to include this header.

All overlayfs c files include overlayfs.h and overlayfs.h itself
refers to some structs defined in ovl_entry.h, so it seems more
logic to include ovl_entry.h from overlayfs.h than from c files.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:27 +01:00
zhangyi (F)
07f6fff148 ovl: fix rmdir problem on non-merge dir with origin xattr
An "origin && non-merge" upper dir may have leftover whiteouts that
were created in past mount. overlayfs does no clear this dir when we
delete it, which may lead to rmdir fail or temp file left in workdir.

Simple reproducer:
  mkdir lower upper work merge
  mkdir -p lower/dir
  touch lower/dir/a
  mount -t overlay overlay -olowerdir=lower,upperdir=upper,\
    workdir=work merge
  rm merge/dir/a
  umount merge
  rm -rf lower/*
  touch lower/dir  (*)
  mount -t overlay overlay -olowerdir=lower,upperdir=upper,\
    workdir=work merge
  rm -rf merge/dir

Syslog dump:
  overlayfs: cleanup of 'work/#7' failed (-39)

(*): if we do not create the regular file, the result is different:
  rm: cannot remove "dir/": Directory not empty

This patch adds a check for the case of non-merge dir that may contain
whiteouts, and calls ovl_check_empty_dir() to check and clear whiteouts
from upper dir when an empty dir is being deleted.

[amir: split patch from ovl_check_empty_dir() cleanup
       rename ovl_is_origin() to ovl_may_have_whiteouts()
       check OVL_WHITEOUTS flag instead of checking origin xattr]

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:27 +01:00
zhangyi (F)
95e598e7ac ovl: simplify ovl_check_empty_and_clear()
Filter out non-whiteout non-upper entries from list of merge dir entries
while checking if merge dir is empty in ovl_check_empty_dir().
The remaining work for ovl_clear_empty() is to clear all entries on the
list.

[amir: split patch from rmdir bug fix]

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:27 +01:00
Amir Goldstein
b79e05aaa1 ovl: no direct iteration for dir with origin xattr
If a non-merge dir in an overlay mount has an overlay.origin xattr, it
means it was once an upper merge dir, which may contain whiteouts and
then the lower dir was removed under it.

Do not iterate real dir directly in this case to avoid exposing whiteouts.

[SzM] Set OVL_WHITEOUT for all merge directories as well.

[amir] A directory that was just copied up does not have the OVL_WHITEOUTS
flag. We need to set it to fix merge dir iteration.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:26 +01:00
Amir Goldstein
4eae06de48 ovl: lockdep annotate of nested OVL_I(inode)->lock
This fixes a lockdep splat when mounting a nested overlayfs.

Fixes: a015dafcaf5b ("ovl: use ovl_inode mutex to synchronize...")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09 10:23:26 +01:00
Theodore Ts'o
2325306802 ext4: improve smp scalability for inode generation
->s_next_generation is protected by s_next_gen_lock but its usage
pattern is very primitive.  We don't actually need sequentially
increasing new generation numbers, so let's use prandom_u32() instead.

Reported-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-11-08 22:23:20 -05:00
Mimi Zohar
bb02b186d0 ima: call ima_file_free() prior to calling fasync
The file hash is calculated and written out as an xattr after
calling fasync().  In order for the file data and metadata to be
written out to disk at the same time, this patch calculates the
file hash and stores it as an xattr before calling fasync.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Mimi Zohar
46cdc6d533 vfs: fix mounting a filesystem with i_version
The mount i_version flag is not enabled in the new sb_flags.  This patch
adds the missing SB_I_VERSION flag.

Fixes: e462ec5 "VFS: Differentiate mount flags (MS_*) from internal
       superblock flags"
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Arvind Yadav
4670269fab eCryptfs: constify attribute_group structures.
attribute_groups are not supposed to change at runtime. All functions
working with attribute_groups provided by <linux/sysfs.h> work with const
attribute_group. So mark the non-const structs as const.

File size before:
   text	   data	    bss	    dec	    hex	filename
   6122	    636	     24	   6782	   1a7e	fs/ecryptfs/main.o

File size After adding 'const':
   text	   data	    bss	    dec	    hex	filename
   6186	    604	     24	   6814	   1a9e	fs/ecryptfs/main.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2017-11-08 17:38:14 +00:00
Ingo Molnar
8a103df440 Merge branch 'linus' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-08 10:17:15 +01:00
Andrew Elble
95da1b3a5a nfsd: deal with revoked delegations appropriately
If a delegation has been revoked by the server, operations using that
delegation should error out with NFS4ERR_DELEG_REVOKED in the >4.1
case, and NFS4ERR_BAD_STATEID otherwise.

The server needs NFSv4.1 clients to explicitly free revoked delegations.
If the server returns NFS4ERR_DELEG_REVOKED, the client will do that;
otherwise it may just forget about the delegation and be unable to
recover when it later sees SEQ4_STATUS_RECALLABLE_STATE_REVOKED set on a
SEQUENCE reply.  That can cause the Linux 4.1 client to loop in its
stage manager.

Signed-off-by: Andrew Elble <aweits@rit.edu>
Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:44:02 -05:00
Vasily Averin
7e981a8afa nfsd: use nfs->ns.inum as net ID
Publishing of net pointer is not safe,
let's use nfs->ns.inum instead

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:44:01 -05:00
Arnd Bergmann
256a89fa3d nfds: avoid gettimeofday for nfssvc_boot time
do_gettimeofday() is deprecated and we should generally use time64_t
based functions instead.

In case of nfsd, all three users of nfssvc_boot only use the initial
time as a unique token, and are not affected by it overflowing, so they
are not affected by the y2038 overflow.

This converts the structure to timespec64 anyway and adds comments
to all uses, to document that we have thought about it and avoid
having to look at it again.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:44:00 -05:00
Elena Reshetova
818a34eb26 fs, nfsd: convert nfs4_file.fi_ref from atomic_t to refcount_t
atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable nfs4_file.fi_ref is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:43:59 -05:00
Elena Reshetova
cff7cb2ece fs, nfsd: convert nfs4_cntl_odstate.co_odcount from atomic_t to refcount_t
atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable nfs4_cntl_odstate.co_odcount is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:43:59 -05:00
Elena Reshetova
a15dfcd529 fs, nfsd: convert nfs4_stid.sc_count from atomic_t to refcount_t
atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable nfs4_stid.sc_count is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:43:58 -05:00
Vasily Averin
dc3033e16c lockd: double unregister of inetaddr notifiers
lockd_up() can call lockd_unregister_notifiers twice:
inside lockd_start_svc() when it calls lockd_svc_exit_thread()
and then in error path of lockd_up()

Patch forces lockd_start_svc() to unregister notifiers in all error cases
and removes extra unregister in error path of lockd_up().

Fixes: cb7d224f82e4 "lockd: unregister notifier blocks if the service ..."
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:43:58 -05:00
J. Bruce Fields
53da6a53e1 nfsd4: catch some false session retries
The spec allows us to return NFS4ERR_SEQ_FALSE_RETRY if we notice that
the client is making a call that matches a previous (slot, seqid) pair
but that *isn't* actually a replay, because some detail of the call
doesn't actually match the previous one.

Catching every such case is difficult, but we may as well catch a few
easy ones.  This also handles the case described in the previous patch,
in a different way.

The spec does however require us to catch the case where the difference
is in the rpc credentials.  This prevents somebody from snooping another
user's replies by fabricating retries.

(But the practical value of the attack is limited by the fact that the
replies with the most sensitive data are READ replies, which are not
normally cached.)

Tested-by: Olga Kornievskaia <aglo@umich.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:43:57 -05:00
J. Bruce Fields
085def3ade nfsd4: fix cached replies to solo SEQUENCE compounds
Currently our handling of 4.1+ requests without "cachethis" set is
confusing and not quite correct.

Suppose a client sends a compound consisting of only a single SEQUENCE
op, and it matches the seqid in a session slot (so it's a retry), but
the previous request with that seqid did not have "cachethis" set.

The obvious thing to do might be to return NFS4ERR_RETRY_UNCACHED_REP,
but the protocol only allows that to be returned on the op following the
SEQUENCE, and there is no such op in this case.

The protocol permits us to cache replies even if the client didn't ask
us to.  And it's easy to do so in the case of solo SEQUENCE compounds.

So, when we get a solo SEQUENCE, we can either return the previously
cached reply or NFSERR_SEQ_FALSE_RETRY if we notice it differs in some
way from the original call.

Currently, we're returning a corrupt reply in the case a solo SEQUENCE
matches a previous compound with more ops.  This actually matters
because the Linux client recently started doing this as a way to recover
from lost replies to idempotent operations in the case the process doing
the original reply was killed: in that case it's difficult to keep the
original arguments around to do a real retry, and the client no longer
cares what the result is anyway, but it would like to make sure that the
slot's sequence id has been incremented, and the solo SEQUENCE assures
that: if the server never got the original reply, it will increment the
sequence id.  If it did get the original reply, it won't increment, and
nothing else that about the reply really matters much.  But we can at
least attempt to return valid xdr!

Tested-by: Olga Kornievskaia <aglo@umich.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:43:57 -05:00
Greg Kroah-Hartman
2b2d8788dd debugfs: Remove redundant license text
Now that the SPDX tag is in all debugfs files, that identifies the
license in a specific and legally-defined manner.  So the extra GPL text
wording can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:03 +01:00
Greg Kroah-Hartman
3bce94fd5f debugfs: add SPDX identifiers to all debugfs files
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the debugfs files files with the correct SPDX license identifier
based on the license text in the file itself.  The SPDX identifier is a
legally binding shorthand, which can be used instead of the full boiler
plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:03 +01:00
Nicolai Stange
7d39bc50c4 debugfs: defer debugfs_fsdata allocation to first usage
Currently, __debugfs_create_file allocates one struct debugfs_fsdata
instance for every file created. However, there are potentially many
debugfs file around, most of which are never touched by userspace.

Thus, defer the allocations to the first usage, i.e. to the first
debugfs_file_get().

A dentry's ->d_fsdata starts out to point to the "real", user provided
fops. After a debugfs_fsdata instance has been allocated (and the real
fops pointer has been moved over into its ->real_fops member),
->d_fsdata is changed to point to it from then on. The two cases are
distinguished by setting BIT(0) for the real fops case.

struct debugfs_fsdata's foremost purpose is to track active users and to
make debugfs_remove() block until they are done. Since no debugfs_fsdata
instance means no active users, make debugfs_remove() return immediately
in this case.

Take care of possible races between debugfs_file_get() and
debugfs_remove(): either debugfs_remove() must see a debugfs_fsdata
instance and thus wait for possible active users or debugfs_file_get() must
see a dead dentry and return immediately.

Make a dentry's ->d_release(), i.e. debugfs_release_dentry(), check whether
->d_fsdata is actually a debugfs_fsdata instance before kfree()ing it.

Similarly, make debugfs_real_fops() check whether ->d_fsdata is actually
a debugfs_fsdata instance before returning it, otherwise emit a warning.

The set of possible error codes returned from debugfs_file_get() has grown
from -EIO to -EIO and -ENOMEM. Make open_proxy_open() and full_proxy_open()
pass the -ENOMEM onwards to their callers.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:03 +01:00
Nicolai Stange
154b9d7512 debugfs: call debugfs_real_fops() only after debugfs_file_get()
The current implementation of debugfs_real_fops() relies on a
debugfs_fsdata instance to be installed at ->d_fsdata.

With future patches introducing lazy allocation of these, this requirement
will be guaranteed to be fullfilled only inbetween a
debugfs_file_get()/debugfs_file_put() pair.

The full proxies' fops implemented by debugfs happen to be the only
offenders. Fix them up by moving their debugfs_real_fops() calls past those
to debugfs_file_get().

full_proxy_release() is special as it doesn't invoke debugfs_file_get() at
all. Leave it alone for now.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:03 +01:00
Nicolai Stange
c9afbec270 debugfs: purge obsolete SRCU based removal protection
Purge the SRCU based file removal race protection in favour of the new,
refcount based debugfs_file_get()/debugfs_file_put() API.

Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Nicolai Stange
69d29f9e6a debugfs: convert to debugfs_file_get() and -put()
Convert all calls to the now obsolete debugfs_use_file_start() and
debugfs_use_file_finish() from the debugfs core itself to the new
debugfs_file_get() and debugfs_file_put() API.

Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Nicolai Stange
055ab8e3e3 debugfs: debugfs_real_fops(): drop __must_hold sparse annotation
Currently, debugfs_real_fops() is annotated with a
__must_hold(&debugfs_srcu) sparse annotation.

With the conversion of the SRCU based protection of users against
concurrent file removals to a per-file refcount based scheme, this becomes
wrong.

Drop this annotation.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Nicolai Stange
e9117a5a4b debugfs: implement per-file removal protection
Since commit 49d200deaa68 ("debugfs: prevent access to removed files'
private data"), accesses to a file's private data are protected from
concurrent removal by covering all file_operations with a SRCU read section
and sychronizing with those before returning from debugfs_remove() by means
of synchronize_srcu().

As pointed out by Johannes Berg, there are debugfs files with forever
blocking file_operations. Their corresponding SRCU read side sections would
block any debugfs_remove() forever as well, even unrelated ones. This
results in a livelock. Because a remover can't cancel any indefinite
blocking within foreign files, this is a problem.

Resolve this by introducing support for more granular protection on a
per-file basis.

This is implemented by introducing an  'active_users' refcount_t to the
per-file struct debugfs_fsdata state. At file creation time, it is set to
one and a debugfs_remove() will drop that initial reference. The new
debugfs_file_get() and debugfs_file_put(), intended to be used in place of
former debugfs_use_file_start() and debugfs_use_file_finish(), increment
and decrement it respectively. Once the count drops to zero,
debugfs_file_put() will signal a completion which is possibly being waited
for from debugfs_remove().
Thus, as long as there is a debugfs_file_get() not yet matched by a
corresponding debugfs_file_put() around, debugfs_remove() will block.

Actual users of debugfs_use_file_start() and -finish() will get converted
to the new debugfs_file_get() and debugfs_file_put() by followup patches.

Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data")
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Nicolai Stange
7c8d469877 debugfs: add support for more elaborate ->d_fsdata
Currently, the user provided fops, "real_fops", are stored directly into
->d_fsdata.

In order to be able to store more per-file state and thus prepare for more
granular file removal protection, wrap the real_fops into a dynamically
allocated container struct, debugfs_fsdata.

A struct debugfs_fsdata gets allocated at file creation and freed from the
newly intoduced ->d_release().

Finally, move the implementation of debugfs_real_fops() out of the public
debugfs header such that struct debugfs_fsdata's declaration can be kept
private.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Ingo Molnar
8c5db92a70 Merge branch 'linus' into locking/core, to resolve conflicts
Conflicts:
	include/linux/compiler-clang.h
	include/linux/compiler-gcc.h
	include/linux/compiler-intel.h
	include/uapi/linux/stddef.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-07 10:32:44 +01:00
Chao Yu
a5fd505092 f2fs: trace checkpoint reason in fsync()
This patch slightly changes need_do_checkpoint to return the detail
info that indicates why we need do checkpoint, then caller could print
it with trace message.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-11-06 17:01:20 -08:00
Chao Yu
e8ed90a6d9 f2fs: keep isize once block is reserved cross EOF
Without FADVISE_KEEP_SIZE_BIT, we will try to recover file size
according to last non-hole block, so in fallocate(), we must set
FADVISE_KEEP_SIZE_BIT flag once we have preallocated block cross
EOF, instead of when all preallocation is success. Otherwise, file
size will be incorrect due to lack of this flag.

Simple testcase to reproduce this:

1. echo 2 > /sys/fs/f2fs/<device>/inject_type
2. echo 10 > /sys/fs/f2fs/<device>/inject_rate
3. run tests/generic/392
4. disable fault injection
5. do remount

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-11-06 17:00:09 -08:00
Christoph Hellwig
181fdfe662 xfs: mark xlog_verify_dest_ptr STATIC
We already did it in the forward declaration, but not for the function
body itself.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-11-06 11:57:39 -08:00