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After a few unsuccessful NFS mount attempts in which the client and
server cannot agree on an authentication flavor both support, the
client panics. nfs_umount() is invoked in the kernel in this case.
Turns out nfs_umount()'s UMNT RPC invocation causes the RPC client to
write off the end of the rpc_clnt's iostat array. This is because the
mount client's nrprocs field is initialized with the count of defined
procedures (two: MNT and UMNT), rather than the size of the client's
proc array (four).
The fix is to use the same initialization technique used by most other
upper layer clients in the kernel.
Introduced by commit 0b524123, which failed to update nrprocs when
support was added for UMNT in the kernel.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=24302
BugLink: http://bugs.launchpad.net/bugs/683938
Reported-by: Stefan Bader <stefan.bader@canonical.com>
Tested-by: Stefan Bader <stefan.bader@canonical.com>
Cc: stable@kernel.org # >= 2.6.32
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Due to newly-introduced 'coherency=full' O_DIRECT writes also takes the EX
rw_lock like buffered writes did(rw_level == 1), it turns out messing the
usage of 'level' in ocfs2_dio_end_io() up, which caused i_alloc_sem being
failed to get up_read'd correctly.
This patch tries to teach ocfs2_dio_end_io to understand well on all locking
stuffs by explicitly introducing a new bit for i_alloc_sem in iocb's private
data, just like what we did for rw_lock.
Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
o2dlm was not migrating resources with zero locks because it assumed that that
resource would get purged by dlm_thread. However, some usage patterns involve
creating and dropping locks at a high rate leading to the migrate thread seeing
zero locks but the purge thread seeing an active reference. When this happens,
the dlm_thread cannot purge the resource and the migrate thread sees no reason
to migrate that resource. The spell is broken when the migrate thread catches
the resource with a lock.
The fix is to make the migrate thread also consider the reference map.
This usage pattern can be triggered by userspace on userdlm locks and flocks.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Now that we don't mark VFS inodes dirty anymore for internal
timestamp changes, but rely on the transaction subsystem to push
them out, we need to explicitly log the source inode in rename after
updating it's timestamps to make sure the changes actually get
forced out by sync/fsync or an AIL push.
We already account for the fourth inode in the log reservation, as a
rename of directories needs to update the nlink field, so just
adding the xfs_trans_log_inode call is enough.
This fixes the xfsqa 065 regression introduced by:
"xfs: don't use vfs writeback for pure metadata modifications"
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
If the orphan item doesn't exist, we return 1, which doesn't make any sense to
the callers. Instead return -ENOENT if we didn't find the item. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Since the fast caching uses normal tree locking, we can possibly deadlock if we
get to the caching via a btrfs_search_slot() on the tree_root. So just check to
see if the root we are on is the tree root, and just don't do the fast caching.
Reported-by: Sage Weil <sage@newdream.net>
Signed-off-by: Josef Bacik <josef@redhat.com>
Currently if the space cache inode generation number doesn't match the
generation number in the space cache header we will just fail to load the space
cache, but we won't mark the space cache as an error, so we'll keep getting that
error each time somebody tries to cache that block group until we actually clear
the thing. Fix this by marking the space cache as having an error so we only
get the message once. This patch also makes it so that we don't try and setup
space cache for a block group that isn't cached, since we won't be able to write
it out anyway. None of these problems are actual problems, they are just
annoying and sub-optimal. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
This fixes a bug where we use dip after we have freed it. Instead just use the
file_offset that was passed to the function. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
As the FIXME points out correctly, now filldir() itself returns -EOVERFLOW if
it not possible to represent the inode number supplied by the filesystem in
the field provided by userspace.
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
If vfs_getattr in fill_post_wcc returns an error, we don't
set fh_post_change.
For NFSv4, this can result in set_change_info triggering a BUG_ON.
i.e. fh_post_saved being zero isn't really a bug.
So:
- instead of BUGging when fh_post_saved is zero, just clear ->atomic.
- if vfs_getattr fails in fill_post_wcc, take a copy of i_ctime anyway.
This will be used i seg_change_info, but not overly trusted.
- While we are there, remove the pointless 'if' statements in set_change_info.
There is no harm setting all the values.
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When a nfs_page is freed, nfs_free_request is called which also calls
nfs_clear_request to clean out the lock and open contexts and free the
pagecache page.
However, a couple of places in the nfs code call nfs_clear_request
themselves. What happens here if the refcount on the request is still high?
We'll be releasing contexts and freeing pointers while the request is
possibly still in use.
Remove those bare calls to nfs_clear_context. That should only be done when
the request is being freed.
Note that when doing this, we need to watch out for tests of req->wb_page.
Previously, nfs_set_page_tag_locked() and nfs_clear_page_tag_locked()
would check the value of req->wb_page to figure out if the page is mapped
into the nfsi->nfs_page_tree. We now indicate the page is mapped using
the new bit PG_MAPPED in req->wb_flags .
Reported-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When nfs client(kernel) don't support NFSv4, maybe user build
kernel without NFSv4, there is a problem.
Using command "mount SERVER-IP:/nfsv3 /mnt/" to mount NFSv3
filesystem, mount should should success, but fail and get error:
"mount.nfs: an incorrect mount option was specified"
System call mount "nfs"(not "nfs4") with "vers=4",
if CONFIG_NFS_V4 is not defined, the "vers=4" will be parsed
as invalid argument and kernel return EINVAL to nfs-utils.
About that, we really want get EPROTONOSUPPORT rather than
EINVAL. This path make sure kernel parses argument success,
and return EPROTONOSUPPORT at nfs_validate_mount_data().
Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The commit 129a84de2347002f09721cda3155ccfd19fade40 (locks: fix F_GETLK
regression (failure to find conflicts)) fixed the posix_test_lock()
function by itself, however, its usage in NFS changed by the commit
9d6a8c5c213e34c475e72b245a8eb709258e968c (locks: give posix_test_lock
same interface as ->lock) remained broken - subsequent NFS-specific
locking code received F_UNLCK instead of the user-specified lock type.
To fix the problem, fl->fl_type needs to be saved before the
posix_test_lock() call and restored if no local conflicts were reported.
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=23892
Tested-by: Alexander Morozov <amorozov@etersoft.ru>
Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Cc: <stable@kernel.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
An update of mode bits can result in ACL value being changed. We need
to mark the acl cache invalid when we update mode. Similarly we need
to update file attribute when we change ACL value
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We should not try to open a file descriptor for the overflow event since this
will always fail.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
If fanotify_init is unable to allocate a new fsnotify group it will
return but will not drop its reference on the associated user struct.
Drop that reference on error.
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
If inotify_init is unable to allocate a new file for the new inotify
group we leak the new group. This patch drops the reference on the
group on file allocation failure.
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
cc: stable@kernel.org
Signed-off-by: Eric Paris <eparis@redhat.com>
When fanotify_release() is called, there may still be processes waiting for
access permission. Currently only processes for which an event has already been
queued into the groups access list will be woken up. Processes for which no
event has been queued will continue to sleep and thus cause a deadlock when
fsnotify_put_group() is called.
Furthermore there is a race allowing further processes to be waiting on the
access wait queue after wake_up (if they arrive before clear_marks_by_group()
is called).
This patch corrects this by setting a flag to inform processes that the group
is about to be destroyed and thus not to wait for access permission.
[additional changelog from eparis]
Lets think about the 4 relevant code paths from the PoV of the
'operator' 'listener' 'responder' and 'closer'. Where operator is the
process doing an action (like open/read) which could require permission.
Listener is the task (or in this case thread) slated with reading from
the fanotify file descriptor. The 'responder' is the thread responsible
for responding to access requests. 'Closer' is the thread attempting to
close the fanotify file descriptor.
The 'operator' is going to end up in:
fanotify_handle_event()
get_response_from_access()
(THIS BLOCKS WAITING ON USERSPACE)
The 'listener' interesting code path
fanotify_read()
copy_event_to_user()
prepare_for_access_response()
(THIS CREATES AN fanotify_response_event)
The 'responder' code path:
fanotify_write()
process_access_response()
(REMOVE A fanotify_response_event, SET RESPONSE, WAKE UP 'operator')
The 'closer':
fanotify_release()
(SUPPOSED TO CLEAN UP THE REST OF THIS MESS)
What we have today is that in the closer we remove all of the
fanotify_response_events and set a bit so no more response events are
ever created in prepare_for_access_response().
The bug is that we never wake all of the operators up and tell them to
move along. You fix that in fanotify_get_response_from_access(). You
also fix other operators which haven't gotten there yet. So I agree
that's a good fix.
[/additional changelog from eparis]
[remove additional changes to minimize patch size]
[move initialization so it was inside CONFIG_FANOTIFY_PERMISSION]
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
In mark_remove_from_mask() we destroy marks that have their event mask cleared.
Thus we should not allow the creation of those marks in the first place.
With this patch we check if the mask given from user is 0 in case of FAN_MARK_ADD.
If so we return an error. Same for FAN_MARK_REMOVE since this does not have any
effect.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
If adding a mount or inode mark failed fanotify_free_mark() is called explicitly.
But at this time the mark has already been put into the destroy list of the
fsnotify_mark kernel thread. If the thread is too slow it will try to decrease
the reference of a mark, that has already been freed by fanotify_free_mark().
(If its fast enough it will only decrease the marks ref counter from 2 to 1 - note
that the counter has been increased to 2 in add_mark() - which has practically no
effect.)
This patch fixes the ref counting by not calling free_mark() explicitly, but
decreasing the ref counter and rely on the fsnotify_mark thread to cleanup in
case adding the mark has failed.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
Unsetting FMODE_NONOTIFY in fsnotify_open() is too late, since fsnotify_perm()
is called before. If FMODE_NONOTIFY is set fsnotify_perm() will skip permission
checks, so a user can still disable permission checks by setting this flag
in an open() call.
This patch corrects this by unsetting the flag before fsnotify_perm is called.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
If no event was sent to userspace we cannot expect userspace to respond to
permissions requests. Today such requests just hang forever. This patch will
deny any permissions event which was unable to be sent to userspace.
Reported-by: Tvrtko Ursulin <tvrtko.ursulin@sophos.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
It's possible that cifs_mount will call cifs_build_path_to_root on a
newly instantiated cifs_sb. In that case, it's likely that the
master_tlink pointer has not yet been instantiated.
Fix this by having cifs_build_path_to_root take a cifsTconInfo pointer
as well, and have the caller pass that in.
Reported-and-Tested-by: Robbert Kouprie <robbert@exx.nl>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This function will return 0 if everything went ok. Commit 9d002df4
however added a block of code after the following check for
rc == -EREMOTE. With that change and when rc == 0, doing the
"goto mount_fail_check" here skips that code, leaving the tlink_tree
and master_tlink pointer unpopulated. That causes an oops later
in cifs_root_iget.
Reported-and-Tested-by: Robbert Kouprie <robbert@exx.nl>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
If we're searching for a specific cookie, and it isn't found in the page
cache, we should try an uncached_readdir(). To do so, we return EBADCOOKIE,
but we don't set desc->eof.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
With the recent changes to remove the BKL a mutex was added to the
ioctl entry point for calls to the old ioctl interface. This mutex
needs to be removed because of the need for the expire ioctl to call
back to the daemon to perform a umount and receive a completion
status (via another ioctl).
This should be fine as the new ioctl interface uses much of the same
code and it has been used without a mutex for around a year without
issue, as was the original intention.
Ref: Bugzilla bug 23142
Signed-off-by: Ian Kent <raven@themaw.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
ocfs2_connection_find() returns pointer to bad structure
ocfs2: char is not always signed
Ocfs2: Stop tracking a negative dentry after dentry_iput().
ocfs2: fix memory leak
fs/ocfs2/dlm: Use GFP_ATOMIC under spin_lock
...this string is zeroed out and nothing ever changes it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Some of the code under CONFIG_CIFS_ACL is dependent upon code under
CONFIG_CIFS_EXPERIMENTAL, but the Kconfig options don't reflect that
dependency. Move more of the ACL code out from under
CONFIG_CIFS_EXPERIMENTAL and under CONFIG_CIFS_ACL.
Also move find_readable_file out from other any sort of Kconfig
option and make it a function normally compiled in.
Reported-and-Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Because it caused a chroot ttyname regression in 2.6.36.
As of 2.6.36 ttyname does not work in a chroot. It has already been
reported that screen breaks, and for me this breaks an automated
distribution testsuite, that I need to preserve the ability to run the
existing binaries on for several more years. glibc 2.11.3 which has a
fix for this is not an option.
The root cause of this breakage is:
commit 8df9d1a4142311c084ffeeacb67cd34d190eff74
Author: Miklos Szeredi <mszeredi@suse.cz>
Date: Tue Aug 10 11:41:41 2010 +0200
vfs: show unreachable paths in getcwd and proc
Prepend "(unreachable)" to path strings if the path is not reachable
from the current root.
Two places updated are
- the return string from getcwd()
- and symlinks under /proc/$PID.
Other uses of d_path() are left unchanged (we know that some old
software crashes if /proc/mounts is changed).
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
So remove the nice sounding, but ultimately ill advised change to how
/proc/fd symlinks work.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
reiserfs_acl_chmod() can be called by reiserfs_set_attr() and then take
the reiserfs lock a second time. Thereafter it may call journal_begin()
that definitely requires the lock not to be nested in order to release
it before taking the journal mutex because the reiserfs lock depends on
the journal mutex already.
So, aviod nesting the lock in reiserfs_acl_chmod().
Reported-by: Pawel Zawora <pzawora@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Pawel Zawora <pzawora@gmail.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: <stable@kernel.org> [2.6.32.x+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, the attribute cache timeout for CIFS is hardcoded to 1 second. This
means that the client might have to issue a QPATHINFO/QFILEINFO call every 1
second to verify if something has changes, which seems too expensive. On the
other hand, if the timeout is hardcoded to a higher value, workloads that
expect strict cache coherency might see unexpected results.
Making attribute cache timeout as a tunable will allow us to make a tradeoff
between performance and cache metadata correctness depending on the
application/workload needs.
Add 'actimeo' tunable that can be used to tune the attribute cache timeout.
The default timeout is set to 1 second. Also, display actimeo option value in
/proc/mounts.
It appears to me that 'actimeo' and the proposed (but not yet merged)
'strictcache' option cannot coexist, so care must be taken that we reset the
other option if one of them is set.
Changes since last post:
- fix option parsing and handle possible values correcly
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
* 'for-linus' of git://oss.sgi.com/xfs/xfs:
xfs: only run xfs_error_test if error injection is active
xfs: avoid moving stale inodes in the AIL
xfs: delayed alloc blocks beyond EOF are valid after writeback
xfs: push stale, pinned buffers on trylock failures
xfs: fix failed write truncation handling.
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
cifs: fix parsing of hostname in dfs referrals
cifs: display fsc in /proc/mounts
cifs: enable fscache iff fsc mount option is used explicitly
cifs: allow fsc mount option only if CONFIG_CIFS_FSCACHE is set
cifs: Handle extended attribute name cifs_acl to generate cifs acl blob (try #4)
cifs: Misc. cleanup in cifsacl handling [try #4]
cifs: trivial comment fix for cifs_invalidate_mapping
[CIFS] fs/cifs/Kconfig: CIFS depends on CRYPTO_HMAC
cifs: don't take extra tlink reference in initiate_cifs_search
cifs: Percolate error up to the caller during get/set acls [try #4]
cifs: fix another memleak, in cifs_root_iget
cifs: fix potential use-after-free in cifs_oplock_break_put
We need to ensure that the entries in the nfs_cache_array get cleared
when the page is removed from the page cache. To do so, we use the
freepage address_space operation.
Change nfs_readdir_clear_array to use kmap_atomic(), so that the
function can be safely called from all contexts.
Finally, modify the cache_page_release helper to call
nfs_readdir_clear_array directly, when dealing with an anonymous
page from 'uncached_readdir'.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fill in the local lock with response data if appropriate,
and don't call posix_lock_file when reading locks.
Signed-off-by: Herb Shiu <herb_shiu@tcloudcomputing.com>
Acked-by: Greg Farnum <gregf@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
Previously the kernel client incorrectly assumed everything was a directory.
Signed-off-by: Herb Shiu <herb_shiu@tcloudcomputing.com>
Acked-by: Greg Farnum <gregf@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
last may be NULL, but we dereference it in the else branch without
checking. Normally it doesn't trigger because last == NULL when fpos == 2,
but it could happen on a newly opened dir if the user seeks forward.
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Recent tests writing lots of small files showed the flusher thread
being CPU bound and taking a long time to do allocations on a debug
kernel. perf showed this as the prime reason:
samples pcnt function DSO
_______ _____ ___________________________ _________________
224648.00 36.8% xfs_error_test [kernel.kallsyms]
86045.00 14.1% xfs_btree_check_sblock [kernel.kallsyms]
39778.00 6.5% prandom32 [kernel.kallsyms]
37436.00 6.1% xfs_btree_increment [kernel.kallsyms]
29278.00 4.8% xfs_btree_get_rec [kernel.kallsyms]
27717.00 4.5% random32 [kernel.kallsyms]
Walking btree blocks during allocation checking them requires each
block (a cache hit, so no I/O) call xfs_error_test(), which then
does a random32() call as the first operation. IOWs, ~50% of the
CPU is being consumed just testing whether we need to inject an
error, even though error injection is not active.
Kill this overhead when error injection is not active by adding a
global counter of active error traps and only calling into
xfs_error_test when fault injection is active.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
When an inode has been marked stale because the cluster is being
freed, we don't want to (re-)insert this inode into the AIL. There
is a race condition where the cluster buffer may be unpinned before
the inode is inserted into the AIL during transaction committed
processing. If the buffer is unpinned before the inode item has been
committed and inserted, then it is possible for the buffer to be
released and hence processthe stale inode callbacks before the inode
is inserted into the AIL.
In this case, we then insert a clean, stale inode into the AIL which
will never get removed by an IO completion. It will, however, get
reclaimed and that triggers an assert in xfs_inode_free()
complaining about freeing an inode still in the AIL.
This race can be avoided by not moving stale inodes forward in the AIL
during transaction commit completion processing. This closes the
race condition by ensuring we never insert clean stale inodes into
the AIL. It is safe to do this because a dirty stale inode, by
definition, must already be in the AIL.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
There is an assumption in the parts of XFS that flushing a dirty
file will make all the delayed allocation blocks disappear from an
inode. That is, that after calling xfs_flush_pages() then
ip->i_delayed_blks will be zero.
This is an invalid assumption as we may have specualtive
preallocation beyond EOF and they are recorded in
ip->i_delayed_blks. A flush of the dirty pages of an inode will not
change the state of these blocks beyond EOF, so a non-zero
deeelalloc block count after a flush is valid.
The bmap code has an invalid ASSERT() that needs to be removed, and
the swapext code has a bug in that while it swaps the data forks
around, it fails to swap the i_delayed_blks counter associated with
the fork and hence can get the block accounting wrong.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
As reported by Nick Piggin, XFS is suffering from long pauses under
highly concurrent workloads when hosted on ramdisks. The problem is
that an inode buffer is stuck in the pinned state in memory and as a
result either the inode buffer or one of the inodes within the
buffer is stopping the tail of the log from being moved forward.
The system remains in this state until a periodic log force issued
by xfssyncd causes the buffer to be unpinned. The main problem is
that these are stale buffers, and are hence held locked until the
transaction/checkpoint that marked them state has been committed to
disk. When the filesystem gets into this state, only the xfssyncd
can cause the async transactions to be committed to disk and hence
unpin the inode buffer.
This problem was encountered when scaling the busy extent list, but
only the blocking lock interface was fixed to solve the problem.
Extend the same fix to the buffer trylock operations - if we fail to
lock a pinned, stale buffer, then force the log immediately so that
when the next attempt to lock it comes around, it will have been
unpinned.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Since the move to the new truncate sequence we call xfs_setattr to
truncate down excessively instanciated blocks. As shown by the testcase
in kernel.org BZ #22452 that doesn't work too well. Due to the confusion
of the internal inode size, and the VFS inode i_size it zeroes data that
it shouldn't.
But full blown truncate seems like overkill here. We only instanciate
delayed allocations in the write path, and given that we never released
the iolock we can't have converted them to real allocations yet either.
The only nasty case is pre-existing preallocation which we need to skip.
We already do this for page discard during writeback, so make the delayed
allocation block punching a generic function and call it from the failed
write path as well as xfs_aops_discard_page. The callers are
responsible for ensuring that partial blocks are not truncated away,
and that they hold the ilock.
Based on a fix originally from Christoph Hellwig. This version used
filesystem blocks as the range unit.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
We need to use the cookie from the previous array entry, not the
actual cookie that we are searching for (except for the case of
uncached_readdir).
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Note: this patch targets 2.6.37 and tries to be as simple as possible.
That is why it adds more copy-and-paste horror into fs/compat.c and
uglifies fs/exec.c, this will be cleanuped later.
compat_copy_strings() plays with bprm->vma/mm directly and thus has
two problems: it lacks the RLIMIT_STACK check and argv/envp memory
is not visible to oom killer.
Export acct_arg_size() and get_arg_page(), change compat_copy_strings()
to use get_arg_page(), change compat_do_execve() to do acct_arg_size(0)
as do_execve() does.
Add the fatal_signal_pending/cond_resched checks into compat_count() and
compat_copy_strings(), this matches the code in fs/exec.c and certainly
makes sense.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Brad Spengler published a local memory-allocation DoS that
evades the OOM-killer (though not the virtual memory RLIMIT):
http://www.grsecurity.net/~spender/64bit_dos.c
execve()->copy_strings() can allocate a lot of memory, but
this is not visible to oom-killer, nobody can see the nascent
bprm->mm and take it into account.
With this patch get_arg_page() increments current's MM_ANONPAGES
counter every time we allocate the new page for argv/envp. When
do_execve() succeds or fails, we change this counter back.
Technically this is not 100% correct, we can't know if the new
page is swapped out and turn MM_ANONPAGES into MM_SWAPENTS, but
I don't think this really matters and everything becomes correct
once exec changes ->mm or fails.
Reported-by: Brad Spengler <spender@grsecurity.net>
Reviewed-and-discussed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
