A bug was introduced with the is_mounted helper function in
commit f7a99c5b7c
Author: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat Jun 9 00:59:08 2012 -0400
get rid of ->mnt_longterm
it's enough to set ->mnt_ns of internal vfsmounts to something
distinct from all struct mnt_namespace out there; then we can
just use the check for ->mnt_ns != NULL in the fast path of
mntput_no_expire()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The intent was to test if the real_mount(vfsmount)->mnt_ns was
NULL_OR_ERR but the code is actually testing real_mount(vfsmount)
and always returning true.
The result is d_absolute_path returning paths it should be hiding.
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
So far I've had one ACK for this, and no other comments. So I think it
is probably time to send this via some suitable tree. I'm guessing that
the vfs tree would be the most appropriate route, but not sure that
there is one at the moment (don't see anything recent at kernel.org)
so in that case I think -mm is the "back up plan". Al, please let me
know if you will take this?
Steve.
---------------------
Following on from the "Re: [PATCH v3] vfs: fix a bug when we do some dio
reads with append dio writes" thread on linux-fsdevel, this patch is my
current version of the fix proposed as option (b) in that thread.
Removing the i_size test from the direct i/o read path at vfs level
means that filesystems now have to deal with requests which are beyond
i_size themselves. These I've divided into three sets:
a) Those with "no op" ->direct_IO (9p, cifs, ceph)
These are obviously not going to be an issue
b) Those with "home brew" ->direct_IO (nfs, fuse)
I've been told that NFS should not have any problem with the larger
i_size, however I've added an extra test to FUSE to duplicate the
original behaviour just to be on the safe side.
c) Those using __blockdev_direct_IO()
These call through to ->get_block() which should deal with the EOF
condition correctly. I've verified that with GFS2 and I believe that
Zheng has verified it for ext4. I've also run the test on XFS and it
passes both before and after this change.
The part of the patch in filemap.c looks a lot larger than it really is
- there are only two lines of real change. The rest is just indentation
of the contained code.
There remains a test of i_size though, which was added for btrfs. It
doesn't cause the other filesystems a problem as the test is performed
after ->direct_IO has been called. It is possible that there is a race
that does matter to btrfs, however this patch doesn't change that, so
its still an overall improvement.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Reported-by: Zheng Liu <gnehzuil.liu@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When using the per-superblock xattr handlers permission checking is
done by the generic code. hfsplus just needs to check for the magic
osx attribute not to leak into protected namespaces.
Also given that the code was obviously copied from JFS the proper
attribution was missing.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Remove the boilerplate code to marshall and unmarhall ACL objects into
xattrs and operate on the posix_acl objects directly. Also move all
the ACL handling code into nfs?acl.c where it belongs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
And instead convert tmpfs to use the new generic ACL code, with two stub
methods provided for in-memory filesystems.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This causes a small behaviour change in that we don't bother to set
ACLs on file creation if the mode bit can express the access permissions
fully, and thus behaving identical to local filesystems.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This contains some major refactoring for the create path so that
inodes are created with the right mode to start with instead of
fixing it up later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Copy the scheme I introduced to btrfs many years ago to only use the
xattr handler for ACLs, but pass plain attrs straight through.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Also don't bother to set up a .get_acl method for symlinks as we do not
support access control (ACLs or even mode bits) for symlinks in Linux,
and create inodes with the proper mode instead of fixing it up later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Also don't bother to set up a .get_acl method for symlinks as we do not
support access control (ACLs or even mode bits) for symlinks in Linux.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This contains some major refactoring for the create path so that
inodes are created with the right mode to start with instead of
fixing it up later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Also don't bother to set up a .get_acl method for symlinks as we do not
support access control (ACLs or even mode bits) for symlinks in Linux.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
f2fs has some weird mode bit handling, so still using the old
chmod code for now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Also don't bother to set up a .get_acl method for symlinks as we do not
support access control (ACLs or even mode bits) for symlinks in Linux.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Rename the current posix_acl_created to __posix_acl_create and add
a fully featured helper to set up the ACLs on file creation that
uses get_acl().
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Rename the current posix_acl_chmod to __posix_acl_chmod and add
a fully featured ACL chmod helper that uses the ->set_acl inode
operation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
With the ->set_acl inode operation we can implement the Posix ACL
xattr handlers in generic code instead of duplicating them all
over the tree.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Factor out the code to get an ACL either from the inode or disk from
check_acl, so that it can be used elsewhere later on.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Also fix befs_iget return value if iget_locked fails.
Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The slow path in __fget_light() can use __fget() to avoid the
code duplication. Saves 232 bytes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Apart from FMODE_PATH check fget_light() and fget_raw_light() are
identical, shift the code into the new helper, __fget_light(fd, mask).
Saves 208 bytes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Apart from FMODE_PATH check fget() and fget_raw() are identical,
shift the code into the new simple helper, __fget(fd, mask). Saves
160 bytes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
put_files_struct() and close_files() do rcu_read_lock() to make
rcu_dereference_check_fdtable() happy.
This looks a bit ugly, files_fdtable() just reads the pointer,
we can simply use rcu_dereference_raw() to avoid the warning.
The patch also changes close_files() to return fdt, this avoids
another rcu_read_lock()/files_fdtable() in put_files_struct().
I think close_files() needs more cleanups:
- we do not need xchg() exactly because we are the last
user of this files_struct
- "if (file)" should be turned into WARN_ON(!file)
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
rcu_dereference_check_fdtable() looks very wrong,
1. rcu_my_thread_group_empty() was added by 844b9a8707 "vfs: fix
RCU-lockdep false positive due to /proc" but it doesn't really
fix the problem. A CLONE_THREAD (without CLONE_FILES) task can
hit the same race with get_files_struct().
And otoh rcu_my_thread_group_empty() can suppress the correct
warning if the caller is the CLONE_FILES (without CLONE_THREAD)
task.
2. files->count == 1 check is not really right too. Even if this
files_struct is not shared it is not safe to access it lockless
unless the caller is the owner.
Otoh, this check is sub-optimal. files->count == 0 always means
it is safe to use it lockless even if files != current->files,
but put_files_struct() has to take rcu_read_lock(). See the next
patch.
This patch removes the buggy checks and turns fcheck_files() into
__fcheck_files() which uses rcu_dereference_raw(), the "unshared"
callers, fget_light() and fget_raw_light(), can use it to avoid
the warning from RCU-lockdep.
fcheck_files() is trivially reimplemented as rcu_lockdep_assert()
plus __fcheck_files().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
kill pointless method instances and don't bother with ->owner - it's
ignored for procfs files anyway, make use of remove_proc_subtree() for
removal, get rid of cell->proc_dir.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
pass owner explicitly to __register_nls(), make register_nls() a macro passing
THIS_MODULE as the owner argument to __register_nls().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't assume that ->dest_count won't change between copy_from_user()
and memdup_user()
* use fdget instead of fget
* don't bother comparing superblocks when we'd already compared vfsmounts
* get rid of excessive goto
* use file_inode() instead of open-coding the sucker
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pass on-disk superblock to qnx4_chkroot() explicitly
* don't leave stale (and unused) pointers in qnx4_super_block
* free stuff in ->kill_sb(); ->put_super() becomes empty and dies
* simplify failure exits
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If ecryptfs_readlink_lower() fails, buf remains an uninitialized
pointer and passing it nd_set_link() won't do anything good.
Fixed by switching ecryptfs_readlink_lower() to saner API - make it
return buf or ERR_PTR(...) and update callers.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull namespace fixes from Eric Biederman:
"This is a set of 3 regression fixes.
This fixes /proc/mounts when using "ip netns add <netns>" to display
the actual mount point.
This fixes a regression in clone that broke lxc-attach.
This fixes a regression in the permission checks for mounting /proc
that made proc unmountable if binfmt_misc was in use. Oops.
My apologies for sending this pull request so late. Al Viro gave
interesting review comments about the d_path fix that I wanted to
address in detail before I sent this pull request. Unfortunately a
bad round of colds kept from addressing that in detail until today.
The executive summary of the review was:
Al: Is patching d_path really sufficient?
The prepend_path, d_path, d_absolute_path, and __d_path family of
functions is a really mess.
Me: Yes, patching d_path is really sufficient. Yes, the code is mess.
No it is not appropriate to rewrite all of d_path for a regression
that has existed for entirely too long already, when a two line
change will do"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
vfs: Fix a regression in mounting proc
fork: Allow CLONE_PARENT after setns(CLONE_NEWPID)
vfs: In d_path don't call d_dname on a mount point
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=AHdo
-----END PGP SIGNATURE-----
Merge tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux
Pull writeback fix from Wu Fengguang:
"Fix data corruption on NFS writeback.
It has been in linux-next for one month"
* tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
writeback: Fix data corruption on NFS
There is a bug in the function nilfs_segctor_collect, which results in
active data being written to a segment, that is marked as clean. It is
possible, that this segment is selected for a later segment
construction, whereby the old data is overwritten.
The problem shows itself with the following kernel log message:
nilfs_sufile_do_cancel_free: segment 6533 must be clean
Usually a few hours later the file system gets corrupted:
NILFS: bad btree node (blocknr=8748107): level = 0, flags = 0x0, nchildren = 0
NILFS error (device sdc1): nilfs_bmap_last_key: broken bmap (inode number=114660)
The issue can be reproduced with a file system that is nearly full and
with the cleaner running, while some IO intensive task is running.
Although it is quite hard to reproduce.
This is what happens:
1. The cleaner starts the segment construction
2. nilfs_segctor_collect is called
3. sc_stage is on NILFS_ST_SUFILE and segments are freed
4. sc_stage is on NILFS_ST_DAT current segment is full
5. nilfs_segctor_extend_segments is called, which
allocates a new segment
6. The new segment is one of the segments freed in step 3
7. nilfs_sufile_cancel_freev is called and produces an error message
8. Loop around and the collection starts again
9. sc_stage is on NILFS_ST_SUFILE and segments are freed
including the newly allocated segment, which will contain active
data and can be allocated at a later time
10. A few hours later another segment construction allocates the
segment and causes file system corruption
This can be prevented by simply reordering the statements. If
nilfs_sufile_cancel_freev is called before nilfs_segctor_extend_segments
the freed segments are marked as dirty and cannot be allocated any more.
Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net>
Reviewed-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Andreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- fix off-by-one in xfs_attr3_rmt_verify
- fix missing destroy_work_on_stack() in xfs_bmapi_allocate
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.10 (GNU/Linux)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=Xpq3
-----END PGP SIGNATURE-----
Merge tag 'xfs-for-linus-v3.13-rc8' of git://oss.sgi.com/xfs/xfs
Pull xfs bugfixes from Ben Myers:
"Here we have a bugfix for an off-by-one in the remote attribute
verifier that results in a forced shutdown which you can hit with v5
superblock by creating a 64k xattr, and a fix for a missing
destroy_work_on_stack() in the allocation worker.
It's a bit late, but they are both fairly straightforward"
* tag 'xfs-for-linus-v3.13-rc8' of git://oss.sgi.com/xfs/xfs:
xfs: Calling destroy_work_on_stack() to pair with INIT_WORK_ONSTACK()
xfs: fix off-by-one error in xfs_attr3_rmt_verify
In case CONFIG_DEBUG_OBJECTS_WORK is defined, it is needed to
call destroy_work_on_stack() which frees the debug object to pair
with INIT_WORK_ONSTACK().
Signed-off-by: Liu, Chuansheng <chuansheng.liu@intel.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
(cherry picked from commit 6f96b3063c)
With CRC check is enabled, if trying to set an attributes value just
equal to the maximum size of XATTR_SIZE_MAX would cause the v3 remote
attr write verification procedure failure, which would yield the back
trace like below:
<snip>
XFS (sda7): Internal error xfs_attr3_rmt_write_verify at line 191 of file fs/xfs/xfs_attr_remote.c
<snip>
Call Trace:
[<ffffffff816f0042>] dump_stack+0x45/0x56
[<ffffffffa0d99c8b>] xfs_error_report+0x3b/0x40 [xfs]
[<ffffffffa0d96edd>] ? _xfs_buf_ioapply+0x6d/0x390 [xfs]
[<ffffffffa0d99ce5>] xfs_corruption_error+0x55/0x80 [xfs]
[<ffffffffa0dbef6b>] xfs_attr3_rmt_write_verify+0x14b/0x1a0 [xfs]
[<ffffffffa0d96edd>] ? _xfs_buf_ioapply+0x6d/0x390 [xfs]
[<ffffffffa0d97315>] ? xfs_bdstrat_cb+0x55/0xb0 [xfs]
[<ffffffffa0d96edd>] _xfs_buf_ioapply+0x6d/0x390 [xfs]
[<ffffffff81184cda>] ? vm_map_ram+0x31a/0x460
[<ffffffff81097230>] ? wake_up_state+0x20/0x20
[<ffffffffa0d97315>] ? xfs_bdstrat_cb+0x55/0xb0 [xfs]
[<ffffffffa0d9726b>] xfs_buf_iorequest+0x6b/0xc0 [xfs]
[<ffffffffa0d97315>] xfs_bdstrat_cb+0x55/0xb0 [xfs]
[<ffffffffa0d97906>] xfs_bwrite+0x46/0x80 [xfs]
[<ffffffffa0dbfa94>] xfs_attr_rmtval_set+0x334/0x490 [xfs]
[<ffffffffa0db84aa>] xfs_attr_leaf_addname+0x24a/0x410 [xfs]
[<ffffffffa0db8893>] xfs_attr_set_int+0x223/0x470 [xfs]
[<ffffffffa0db8b76>] xfs_attr_set+0x96/0xb0 [xfs]
[<ffffffffa0db13b2>] xfs_xattr_set+0x42/0x70 [xfs]
[<ffffffff811df9b2>] generic_setxattr+0x62/0x80
[<ffffffff811e0213>] __vfs_setxattr_noperm+0x63/0x1b0
[<ffffffff81307afe>] ? evm_inode_setxattr+0xe/0x10
[<ffffffff811e0415>] vfs_setxattr+0xb5/0xc0
[<ffffffff811e054e>] setxattr+0x12e/0x1c0
[<ffffffff811c6e82>] ? final_putname+0x22/0x50
[<ffffffff811c708b>] ? putname+0x2b/0x40
[<ffffffff811cc4bf>] ? user_path_at_empty+0x5f/0x90
[<ffffffff811bdfd9>] ? __sb_start_write+0x49/0xe0
[<ffffffff81168589>] ? vm_mmap_pgoff+0x99/0xc0
[<ffffffff811e07df>] SyS_setxattr+0x8f/0xe0
[<ffffffff81700c2d>] system_call_fastpath+0x1a/0x1f
Tests:
setfattr -n user.longxattr -v `perl -e 'print "A"x65536'` testfile
This patch fix it to check the remote EA size is greater than the
XATTR_SIZE_MAX rather than more than or equal to it, because it's
valid if the specified EA value size is equal to the limitation as
per VFS setxattr interface.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
(cherry picked from commit 85dd0707f0)
Commit f5a44db5d2 introduced a regression on filesystems created with
the bigalloc feature (cluster size > blocksize). It causes xfstests
generic/006 and /013 to fail with an unexpected JBD2 failure and
transaction abort that leaves the test file system in a read only state.
Other xfstests run on bigalloc file systems are likely to fail as well.
The cause is the accidental use of a cluster mask where a cluster
offset was needed in ext4_ext_map_blocks().
Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Merge patches from Andrew Morton:
"Ten fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
epoll: do not take the nested ep->mtx on EPOLL_CTL_DEL
sh: add EXPORT_SYMBOL(min_low_pfn) and EXPORT_SYMBOL(max_low_pfn) to sh_ksyms_32.c
drivers/dma/ioat/dma.c: check DMA mapping error in ioat_dma_self_test()
mm/memory-failure.c: transfer page count from head page to tail page after split thp
MAINTAINERS: set up proper record for Xilinx Zynq
mm: remove bogus warning in copy_huge_pmd()
memcg: fix memcg_size() calculation
mm: fix use-after-free in sys_remap_file_pages
mm: munlock: fix deadlock in __munlock_pagevec()
mm: munlock: fix a bug where THP tail page is encountered
The EPOLL_CTL_DEL path of epoll contains a classic, ab-ba deadlock.
That is, epoll_ctl(a, EPOLL_CTL_DEL, b, x), will deadlock with
epoll_ctl(b, EPOLL_CTL_DEL, a, x). The deadlock was introduced with
commmit 67347fe4e6 ("epoll: do not take global 'epmutex' for simple
topologies").
The acquistion of the ep->mtx for the destination 'ep' was added such
that a concurrent EPOLL_CTL_ADD operation would see the correct state of
the ep (Specifically, the check for '!list_empty(&f.file->f_ep_links')
However, by simply not acquiring the lock, we do not serialize behind
the ep->mtx from the add path, and thus may perform a full path check
when if we had waited a little longer it may not have been necessary.
However, this is a transient state, and performing the full loop
checking in this case is not harmful.
The important point is that we wouldn't miss doing the full loop
checking when required, since EPOLL_CTL_ADD always locks any 'ep's that
its operating upon. The reason we don't need to do lock ordering in the
add path, is that we are already are holding the global 'epmutex'
whenever we do the double lock. Further, the original posting of this
patch, which was tested for the intended performance gains, did not
perform this additional locking.
Signed-off-by: Jason Baron <jbaron@akamai.com>
Cc: Nathan Zimmer <nzimmer@sgi.com>
Cc: Eric Wong <normalperson@yhbt.net>
Cc: Nelson Elhage <nelhage@nelhage.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
