get_write_access() is needed for nfsd, not binfmt_aout (the latter
has no business doing anything of that kind, of course)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch converts /proc/pid/fdinfo/ handling routines to seq-file which
is needed to extend seq operations and plug in auxiliary fdinfo provides
from subsystems like eventfd/eventpoll/fsnotify.
Note the proc_fd_link no longer call for proc_fd_info, simply because
the guts of proc_fd_info() got merged into ->show() of that seq_file
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch prepares the ground for further extension of
/proc/pid/fd[info] handling code by moving fdinfo handling
code into fs/proc/fd.c.
I think such move makes both fs/proc/base.c and fs/proc/fd.c
easier to read.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
CC: Al Viro <viro@ZenIV.linux.org.uk>
CC: Alexey Dobriyan <adobriyan@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: James Bottomley <jbottomley@parallels.com>
CC: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
CC: Alexey Dobriyan <adobriyan@gmail.com>
CC: Matthew Helsley <matt.helsley@gmail.com>
CC: "J. Bruce Fields" <bfields@fieldses.org>
CC: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
descriptor-related parts of daemonize, done right. As the
result we simplify the locking rules for ->files - we
hold task_lock in *all* cases when we modify ->files.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
iterates through the opened files in given descriptor table,
calling a supplied function; we stop once non-zero is returned.
Callback gets struct file *, descriptor number and const void *
argument passed to iterator. It is called with files->file_lock
held, so it is not allowed to block.
tty_io, netprio_cgroup and selinux flush_unauthorized_files()
converted to its use.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Similar situation to that of __alloc_fd(); do not use unless you
really have to. You should not touch any descriptor table other
than your own; it's a sure sign of a really bad API design.
As with __alloc_fd(), you *must* use a first-class reference to
struct files_struct; something obtained by get_files_struct(some task)
(let alone direct task->files) will not do. It must be either
current->files, or obtained by get_files_struct(current) by the
owner of that sucker and given to you.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
At that point nobody can see us anyway; everything that
looks at files_fdtable(files) is separated from the
guts of put_files_struct(files) - either since files is
current->files or because we fetched it under task_lock()
and hadn't dropped that yet, or because we'd bumped
files->count while holding task_lock()...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Essentially, alloc_fd() in a files_struct we own a reference to.
Most of the time wanting to use it is a sign of lousy API
design (such as android/binder). It's *not* a general-purpose
interface; better that than open-coding its guts, but again,
playing with other process' descriptor table is a sign of bad
design.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... except for one in android, where the check is different
and already done in caller. No need to recalculate rlimit
many times in alloc_fd() either.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* do copy_to_user() before prepare_for_access_response(); that kills
the need in remove_access_response().
* don't do fd_install() until we are past the last possible failure
exit. Don't use sys_close() on cleanup side - just put_unused_fd()
and fput(). Less racy that way...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
don't mess with sys_close() if copy_to_user() fails; just postpone
fd_install() until we know it hasn't.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The only difference between autofs_dev_ioctl_fd_install() and
fd_install() is __set_close_on_exec() done by the latter. Just
use get_unused_fd_flags(O_CLOEXEC) to allocate the descriptor
and be done with that...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
normally we deal with lock_mount()/umount races by checking that
mountpoint to be is still in our namespace after lock_mount() has
been done. However, do_add_mount() skips that check when called
with MNT_SHRINKABLE in flags (i.e. from finish_automount()). The
reason is that ->mnt_ns may be a temporary namespace created exactly
to contain automounts a-la NFS4 referral handling. It's not the
namespace of the caller, though, so check_mnt() would fail here.
We still need to check that ->mnt_ns is non-NULL in that case,
though.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
- fix a regression related to xfs_sync_worker racing with unmount.
- fix a race while discarding xfs buffers.
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Merge tag 'for-linus-v3.6-rc7' of git://oss.sgi.com/xfs/xfs
Pull xfs bugfixes from Ben Myers:
- fix a regression related to xfs_sync_worker racing with unmount.
- fix a race while discarding xfs buffers.
* tag 'for-linus-v3.6-rc7' of git://oss.sgi.com/xfs/xfs:
xfs: stop the sync worker before xfs_unmountfs
xfs: fix race while discarding buffers [V4]
The format_array_alloc() function is fundamentally racy, in that it
prints the array twice: once to figure out how much space to allocate
for the buffer, and the second time to actually print out the data.
If any of the array contents changes in between, the allocation size may
be wrong, and the end result may be truncated in odd ways.
Just don't do it. Allocate a maximum-sized array up-front, and just
format the array contents once. The only user of the u32_array
interfaces is the Xen spinlock statistics code, and it has 31 entries in
the arrays, so the maximum size really isn't that big, and the end
result is much simpler code without the bug.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
u32_array_open() is racy when multiple threads read from a file with a
seek position of zero, i.e. when two or more simultaneous reads are
occurring after the non-seekable files are created. It is possible that
file->private_data is double-freed because the threads races between
kfree(file->private-data);
and
file->private_data = NULL;
The fix is to only do format_array_alloc() when the file is opened and
free it when it is closed.
Note that because the file has always been non-seekable, you can't open
it and read it multiple times anyway, so the data has always been
generated just once. The difference is that now it is generated at open
time rather than at the time of the first read, and that avoids the
race.
Reported-by: Dave Jones <davej@redhat.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Raghavendra <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cancel work of the xfs_sync_worker before teardown of the log in
xfs_unmountfs. This prevents occasional crashes on unmount like so:
PID: 21602 TASK: ee9df060 CPU: 0 COMMAND: "kworker/0:3"
#0 [c5377d28] crash_kexec at c0292c94
#1 [c5377d80] oops_end at c07090c2
#2 [c5377d98] no_context at c06f614e
#3 [c5377dbc] __bad_area_nosemaphore at c06f6281
#4 [c5377df4] bad_area_nosemaphore at c06f629b
#5 [c5377e00] do_page_fault at c070b0cb
#6 [c5377e7c] error_code (via page_fault) at c070892c
EAX: f300c6a8 EBX: f300c6a8 ECX: 000000c0 EDX: 000000c0 EBP: c5377ed0
DS: 007b ESI: 00000000 ES: 007b EDI: 00000001 GS: ffffad20
CS: 0060 EIP: c0481ad0 ERR: ffffffff EFLAGS: 00010246
#7 [c5377eb0] atomic64_read_cx8 at c0481ad0
#8 [c5377ebc] xlog_assign_tail_lsn_locked at f7cc7c6e [xfs]
#9 [c5377ed4] xfs_trans_ail_delete_bulk at f7ccd520 [xfs]
#10 [c5377f0c] xfs_buf_iodone at f7ccb602 [xfs]
#11 [c5377f24] xfs_buf_do_callbacks at f7cca524 [xfs]
#12 [c5377f30] xfs_buf_iodone_callbacks at f7cca5da [xfs]
#13 [c5377f4c] xfs_buf_iodone_work at f7c718d0 [xfs]
#14 [c5377f58] process_one_work at c024ee4c
#15 [c5377f98] worker_thread at c024f43d
#16 [c5377fbc] kthread at c025326b
#17 [c5377fe8] kernel_thread_helper at c070e834
PID: 26653 TASK: e79143b0 CPU: 3 COMMAND: "umount"
#0 [cde0fda0] __schedule at c0706595
#1 [cde0fe28] schedule at c0706b89
#2 [cde0fe30] schedule_timeout at c0705600
#3 [cde0fe94] __down_common at c0706098
#4 [cde0fec8] __down at c0706122
#5 [cde0fed0] down at c025936f
#6 [cde0fee0] xfs_buf_lock at f7c7131d [xfs]
#7 [cde0ff00] xfs_freesb at f7cc2236 [xfs]
#8 [cde0ff10] xfs_fs_put_super at f7c80f21 [xfs]
#9 [cde0ff1c] generic_shutdown_super at c0333d7a
#10 [cde0ff38] kill_block_super at c0333e0f
#11 [cde0ff48] deactivate_locked_super at c0334218
#12 [cde0ff58] deactivate_super at c033495d
#13 [cde0ff68] mntput_no_expire at c034bc13
#14 [cde0ff7c] sys_umount at c034cc69
#15 [cde0ffa0] sys_oldumount at c034ccd4
#16 [cde0ffb0] system_call at c0707e66
commit 11159a05 added this to xfs_log_unmount and needs to be cleaned up
at a later date.
Signed-off-by: Ben Myers <bpm@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
This function returns the wrong value, which causes the callers to get
the length of the resulting pathname wrong when it contains non-ASCII
characters.
This seems to fix https://bugzilla.samba.org/show_bug.cgi?id=6767
Cc: <stable@vger.kernel.org>
Reported-by: Baldvin Kovacs <baldvin.kovacs@gmail.com>
Reported-and-Tested-by: Nicolas Lefebvre <nico.lefebvre@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
IBM reported a soft lockup after applying the fix for the rename_lock
deadlock. Commit c83ce989cb ("VFS: Fix the nfs sillyrename regression
in kernel 2.6.38") was found to be the culprit.
The nfs sillyrename fix used DCACHE_DISCONNECTED to indicate that the
dentry was killed. This flag can be set on non-killed dentries too,
which results in infinite retries when trying to traverse the dentry
tree.
This patch introduces a separate flag: DCACHE_DENTRY_KILLED, which is
only set in d_kill() and makes try_to_ascend() test only this flag.
IBM reported successful test results with this patch.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The unregister_sysctl_table() function hangs if all references to its
ctl_table_header structure are not dropped.
This can happen sometimes because of a leak in proc_sys_lookup():
proc_sys_lookup() gets a reference to the table via lookup_entry(), but
it does not release it when a subsequent call to sysctl_follow_link()
fails.
This patch fixes this leak by making sure the reference is always
dropped on return.
See also commit 076c3eed2c ("sysctl: Rewrite proc_sys_lookup
introducing find_entry and lookup_entry") which reorganized this code in
3.4.
Tested in Linux 3.4.4.
Signed-off-by: Francesco Ruggeri <fruggeri@aristanetworks.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull a btrfs revert from Chris Mason:
"My for-linus branch has one revert in the new quota code.
We're building up more fixes at etc for the next merge window, but I'm
keeping them out unless they are bigger regressions or have a huge
impact."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Revert "Btrfs: fix some error codes in btrfs_qgroup_inherit()"
Pull GFS2 fixes from Steven Whitehouse:
"Here are three GFS2 fixes for the current kernel tree. These are all
related to the block reservation code which was added at the merge
window. That code will be getting an update at the forthcoming merge
window too. In the mean time though there are a few smaller issues
which should be fixed.
The first patch resolves an issue with write sizes of greater than 32
bits with the size hinting code. The second ensures that the
allocation data structure is initialised when using xattrs and the
third takes into account allocations which may have been made by other
nodes which affect a reservation on the local node."
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-fixes:
GFS2: Take account of blockages when using reserved blocks
GFS2: Fix missing allocation data for set/remove xattr
GFS2: Make write size hinting code common
shared memory mapping is dirtied and unmapped. The lower file was being
released when the eCryptfs file was closed and the dirtied pages could not be
written out.
- Adds a call to the lower filesystem's ->flush() from ecryptfs_flush().
- Fixes a regression, introduced in 2.6.39, when a file is renamed on top of
another file. The target file's inode was not being evicted and the space
taken by the file was not reclaimed until eCryptfs was unmounted.
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Merge tag 'ecryptfs-3.6-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs
Pull ecryptfs fixes from Tyler Hicks:
- Fixes a regression, introduced in 3.6-rc1, when a file is closed
before its shared memory mapping is dirtied and unmapped. The lower
file was being released when the eCryptfs file was closed and the
dirtied pages could not be written out.
- Adds a call to the lower filesystem's ->flush() from
ecryptfs_flush().
- Fixes a regression, introduced in 2.6.39, when a file is renamed on
top of another file. The target file's inode was not being evicted
and the space taken by the file was not reclaimed until eCryptfs was
unmounted.
* tag 'ecryptfs-3.6-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
eCryptfs: Copy up attributes of the lower target inode after rename
eCryptfs: Call lower ->flush() from ecryptfs_flush()
eCryptfs: Write out all dirty pages just before releasing the lower file
This reverts commit 5986802c2f.
Both paths are not error paths but regular cases where non-qgroup
subvols are involved.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
We already use them for openat() and friends, but fstat() also wants to
be able to use O_PATH file descriptors. This should make it more
directly comparable to the O_SEARCH of Solaris.
Note that you could already do the same thing with "fstatat()" and an
empty path, but just doing "fstat()" directly is simpler and faster, so
there is no reason not to just allow it directly.
See also commit 332a2e1244, which did the same thing for fchdir, for
the same reasons.
Reported-by: ольга крыжановская <olga.kryzhanovska@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org # O_PATH introduced in 3.0+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After calling into the lower filesystem to do a rename, the lower target
inode's attributes were not copied up to the eCryptfs target inode. This
resulted in the eCryptfs target inode staying around, rather than being
evicted, because i_nlink was not updated for the eCryptfs inode. This
also meant that eCryptfs didn't do the final iput() on the lower target
inode so it stayed around, as well. This would result in a failure to
free up space occupied by the target file in the rename() operation.
Both target inodes would eventually be evicted when the eCryptfs
filesystem was unmounted.
This patch calls fsstack_copy_attr_all() after the lower filesystem
does its ->rename() so that important inode attributes, such as i_nlink,
are updated at the eCryptfs layer. ecryptfs_evict_inode() is now called
and eCryptfs can drop its final reference on the lower inode.
http://launchpad.net/bugs/561129
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Tested-by: Colin Ian King <colin.king@canonical.com>
Cc: <stable@vger.kernel.org> [2.6.39+]
Since eCryptfs only calls fput() on the lower file in
ecryptfs_release(), eCryptfs should call the lower filesystem's
->flush() from ecryptfs_flush().
If the lower filesystem implements ->flush(), then eCryptfs should try
to flush out any dirty pages prior to calling the lower ->flush(). If
the lower filesystem does not implement ->flush(), then eCryptfs has no
need to do anything in ecryptfs_flush() since dirty pages are now
written out to the lower filesystem in ecryptfs_release().
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Fixes a regression caused by:
821f749 eCryptfs: Revert to a writethrough cache model
That patch reverted some code (specifically, 32001d6f) that was
necessary to properly handle open() -> mmap() -> close() -> dirty pages
-> munmap(), because the lower file could be closed before the dirty
pages are written out.
Rather than reapplying 32001d6f, this approach is a better way of
ensuring that the lower file is still open in order to handle writing
out the dirty pages. It is called from ecryptfs_release(), while we have
a lock on the lower file pointer, just before the lower file gets the
final fput() and we overwrite the pointer.
https://launchpad.net/bugs/1047261
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Artemy Tregubenko <me@arty.name>
Tested-by: Artemy Tregubenko <me@arty.name>
Tested-by: Colin Ian King <colin.king@canonical.com>
The claim_reserved_blks() function was not taking account of
the possibility of "blockages" while performing allocation.
This can be caused by another node allocating something in
the same extent which has been reserved locally.
This patch tests for this condition and then skips the remainder
of the reservation in this case. This is a relatively rare event,
so that it should not affect the general performance improvement
which the block reservations provide.
The claim_reserved_blks() function also appears not to be able
to deal with reservations which cross bitmap boundaries, but
that can be dealt with in a future patch since we don't generate
boundary crossing reservations currently.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Reported-by: David Teigland <teigland@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
This collects up the write size hinting code which is used by the
block reservation subsystem into a single function. At the same
time this also corrects the rounding for this calculation.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
