Commit graph

38390 commits

Author SHA1 Message Date
Linus Torvalds
7e05b807b9 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS fixes from Al Viro:
 "A bunch of assorted fixes, most of them followups to overlayfs merge"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ovl: initialize ->is_cursor
  Return short read or 0 at end of a raw device, not EIO
  isofs: don't bother with ->d_op for normal case
  isofs_cmp(): we'll never see a dentry for . or ..
  overlayfs: fix lockdep misannotation
  ovl: fix check for cursor
  overlayfs: barriers for opening upper-layer directory
  rcu: Provide counterpart to rcu_dereference() for non-RCU situations
  staging: android: logger: Fix log corruption regression
2014-11-02 10:28:43 -08:00
Linus Torvalds
4f4274af70 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "Filipe is nailing down some problems with our skinny extent variation,
  and Dave's patch fixes endian problems in the new super block checks"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix race that makes btrfs_lookup_extent_info miss skinny extent items
  Btrfs: properly clean up btrfs_end_io_wq_cache
  Btrfs: fix invalid leaf slot access in btrfs_lookup_extent()
  btrfs: use macro accessors in superblock validation checks
2014-11-01 10:41:26 -07:00
Linus Torvalds
32e8fd2f8e A set of miscellaneous ext4 bug fixes for 3.18.
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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 bugfixes from Ted Ts'o:
 "A set of miscellaneous ext4 bug fixes for 3.18"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: make ext4_ext_convert_to_initialized() return proper number of blocks
  ext4: bail early when clearing inode journal flag fails
  ext4: bail out from make_indexed_dir() on first error
  jbd2: use a better hash function for the revoke table
  ext4: prevent bugon on race between write/fcntl
  ext4: remove extent status procfs files if journal load fails
  ext4: disallow changing journal_csum option during remount
  ext4: enable journal checksum when metadata checksum feature enabled
  ext4: fix oops when loading block bitmap failed
  ext4: fix overflow when updating superblock backups after resize
2014-10-31 16:22:29 -07:00
Linus Torvalds
e2488ab6ab Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull quota and ext3 fixes from Jan Kara.

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fs, jbd: use a more generic hash function
  quota: Properly return errors from dquot_writeback_dquots()
  ext3: Don't check quota format when there are no quota files
2014-10-31 16:18:47 -07:00
Miklos Szeredi
9f2f7d4c8d ovl: initialize ->is_cursor
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-31 17:47:51 -04:00
David Jeffery
b2de525f09 Return short read or 0 at end of a raw device, not EIO
Author: David Jeffery <djeffery@redhat.com>
Changes to the basic direct I/O code have broken the raw driver when reading
to the end of a raw device.  Instead of returning a short read for a read that
extends partially beyond the device's end or 0 when at the end of the device,
these reads now return EIO.

The raw driver needs the same end of device handling as was added for normal
block devices.  Using blkdev_read_iter, which has the needed size checks,
prevents the EIO conditions at the end of the device.

Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-31 06:33:26 -04:00
Al Viro
b0afd8e5db isofs: don't bother with ->d_op for normal case
we only need it for joliet and case-insensitive mounts

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-31 06:33:17 -04:00
Eric Rannaud
69a91c237a fs: allow open(dir, O_TMPFILE|..., 0) with mode 0
The man page for open(2) indicates that when O_CREAT is specified, the
'mode' argument applies only to future accesses to the file:

	Note that this mode applies only to future accesses of the newly
	created file; the open() call that creates a read-only file
	may well return a read/write file descriptor.

The man page for open(2) implies that 'mode' is treated identically by
O_CREAT and O_TMPFILE.

O_TMPFILE, however, behaves differently:

	int fd = open("/tmp", O_TMPFILE | O_RDWR, 0);
	assert(fd == -1);
	assert(errno == EACCES);

	int fd = open("/tmp", O_TMPFILE | O_RDWR, 0600);
	assert(fd > 0);

For O_CREAT, do_last() sets acc_mode to MAY_OPEN only:

	if (*opened & FILE_CREATED) {
		/* Don't check for write permission, don't truncate */
		open_flag &= ~O_TRUNC;
		will_truncate = false;
		acc_mode = MAY_OPEN;
		path_to_nameidata(path, nd);
		goto finish_open_created;
	}

But for O_TMPFILE, do_tmpfile() passes the full op->acc_mode to
may_open().

This patch lines up the behavior of O_TMPFILE with O_CREAT. After the
inode is created, may_open() is called with acc_mode = MAY_OPEN, in
do_tmpfile().

A different, but related glibc bug revealed the discrepancy:
https://sourceware.org/bugzilla/show_bug.cgi?id=17523

The glibc lazily loads the 'mode' argument of open() and openat() using
va_arg() only if O_CREAT is present in 'flags' (to support both the 2
argument and the 3 argument forms of open; same idea for openat()).
However, the glibc ignores the 'mode' argument if O_TMPFILE is in
'flags'.

On x86_64, for open(), it magically works anyway, as 'mode' is in
RDX when entering open(), and is still in RDX on SYSCALL, which is where
the kernel looks for the 3rd argument of a syscall.

But openat() is not quite so lucky: 'mode' is in RCX when entering the
glibc wrapper for openat(), while the kernel looks for the 4th argument
of a syscall in R10. Indeed, the syscall calling convention differs from
the regular calling convention in this respect on x86_64. So the kernel
sees mode = 0 when trying to use glibc openat() with O_TMPFILE, and
fails with EACCES.

Signed-off-by: Eric Rannaud <e@nanocritical.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-30 15:50:13 -07:00
Jan Kara
ae9e9c6aee ext4: make ext4_ext_convert_to_initialized() return proper number of blocks
ext4_ext_convert_to_initialized() can return more blocks than are
actually allocated from map->m_lblk in case where initial part of the
on-disk extent is zeroed out. Luckily this doesn't have serious
consequences because the caller currently uses the return value
only to unmap metadata buffers. Anyway this is a data
corruption/exposure problem waiting to happen so fix it.

Coverity-id: 1226848
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-30 10:53:17 -04:00
Jan Kara
4f879ca687 ext4: bail early when clearing inode journal flag fails
When clearing inode journal flag, we call jbd2_journal_flush() to force
all the journalled data to their final locations. Currently we ignore
when this fails and continue clearing inode journal flag. This isn't a
big problem because when jbd2_journal_flush() fails, journal is likely
aborted anyway. But it can still lead to somewhat confusing results so
rather bail out early.

Coverity-id: 989044
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-30 10:53:17 -04:00
Jan Kara
6050d47adc ext4: bail out from make_indexed_dir() on first error
When ext4_handle_dirty_dx_node() or ext4_handle_dirty_dirent_node()
fail, there's really something wrong with the fs and there's no point in
continuing further. Just return error from make_indexed_dir() in that
case. Also initialize frames array so that if we return early due to
error, dx_release() doesn't try to dereference uninitialized memory
(which could happen also due to error in do_split()).

Coverity-id: 741300
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-30 10:53:17 -04:00
Theodore Ts'o
d48458d4a7 jbd2: use a better hash function for the revoke table
The old hash function didn't work well for 64-bit block numbers, and
used undefined (negative) shift right behavior.  Use the generic
64-bit hash function instead.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reported-by: Andrey Ryabinin <a.ryabinin@samsung.com>
2014-10-30 10:53:17 -04:00
Dmitry Monakhov
a41537e69b ext4: prevent bugon on race between write/fcntl
O_DIRECT flags can be toggeled via fcntl(F_SETFL). But this value checked
twice inside ext4_file_write_iter() and __generic_file_write() which
result in BUG_ON inside ext4_direct_IO.

Let's initialize iocb->private unconditionally.

TESTCASE: xfstest:generic/036  https://patchwork.ozlabs.org/patch/402445/

#TYPICAL STACK TRACE:
kernel BUG at fs/ext4/inode.c:2960!
invalid opcode: 0000 [#1] SMP
Modules linked in: brd iTCO_wdt lpc_ich mfd_core igb ptp dm_mirror dm_region_hash dm_log dm_mod
CPU: 6 PID: 5505 Comm: aio-dio-fcntl-r Not tainted 3.17.0-rc2-00176-gff5c017 #161
Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011
task: ffff88080e95a7c0 ti: ffff88080f908000 task.ti: ffff88080f908000
RIP: 0010:[<ffffffff811fabf2>]  [<ffffffff811fabf2>] ext4_direct_IO+0x162/0x3d0
RSP: 0018:ffff88080f90bb58  EFLAGS: 00010246
RAX: 0000000000000400 RBX: ffff88080fdb2a28 RCX: 00000000a802c818
RDX: 0000040000080000 RSI: ffff88080d8aeb80 RDI: 0000000000000001
RBP: ffff88080f90bbc8 R08: 0000000000000000 R09: 0000000000001581
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88080d8aeb80
R13: ffff88080f90bbf8 R14: ffff88080fdb28c8 R15: ffff88080fdb2a28
FS:  00007f23b2055700(0000) GS:ffff880818400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f23b2045000 CR3: 000000080cedf000 CR4: 00000000000407e0
Stack:
 ffff88080f90bb98 0000000000000000 7ffffffffffffffe ffff88080fdb2c30
 0000000000000200 0000000000000200 0000000000000001 0000000000000200
 ffff88080f90bbc8 ffff88080fdb2c30 ffff88080f90be08 0000000000000200
Call Trace:
 [<ffffffff8112ca9d>] generic_file_direct_write+0xed/0x180
 [<ffffffff8112f2b2>] __generic_file_write_iter+0x222/0x370
 [<ffffffff811f495b>] ext4_file_write_iter+0x34b/0x400
 [<ffffffff811bd709>] ? aio_run_iocb+0x239/0x410
 [<ffffffff811bd709>] ? aio_run_iocb+0x239/0x410
 [<ffffffff810990e5>] ? local_clock+0x25/0x30
 [<ffffffff810abd94>] ? __lock_acquire+0x274/0x700
 [<ffffffff811f4610>] ? ext4_unwritten_wait+0xb0/0xb0
 [<ffffffff811bd756>] aio_run_iocb+0x286/0x410
 [<ffffffff810990e5>] ? local_clock+0x25/0x30
 [<ffffffff810ac359>] ? lock_release_holdtime+0x29/0x190
 [<ffffffff811bc05b>] ? lookup_ioctx+0x4b/0xf0
 [<ffffffff811bde3b>] do_io_submit+0x55b/0x740
 [<ffffffff811bdcaa>] ? do_io_submit+0x3ca/0x740
 [<ffffffff811be030>] SyS_io_submit+0x10/0x20
 [<ffffffff815ce192>] system_call_fastpath+0x16/0x1b
Code: 01 48 8b 80 f0 01 00 00 48 8b 18 49 8b 45 10 0f 85 f1 01 00 00 48 03 45 c8 48 3b 43 48 0f 8f e3 01 00 00 49 83 7c
24 18 00 75 04 <0f> 0b eb fe f0 ff 83 ec 01 00 00 49 8b 44 24 18 8b 00 85 c0 89
RIP  [<ffffffff811fabf2>] ext4_direct_IO+0x162/0x3d0
 RSP <ffff88080f90bb58>

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Cc: stable@vger.kernel.org
2014-10-30 10:53:16 -04:00
Darrick J. Wong
50460fe8c6 ext4: remove extent status procfs files if journal load fails
If we can't load the journal, remove the procfs files for the extent
status information file to avoid leaking resources.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-30 10:53:16 -04:00
Darrick J. Wong
6b992ff256 ext4: disallow changing journal_csum option during remount
ext4 does not permit changing the metadata or journal checksum feature
flag while mounted.  Until we decide to support that, don't allow a
remount to change the journal_csum flag (right now we silently fail to
change anything).

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-30 10:53:16 -04:00
Darrick J. Wong
98c1a7593f ext4: enable journal checksum when metadata checksum feature enabled
If metadata checksumming is turned on for the FS, we need to tell the
journal to use checksumming too.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-30 10:53:16 -04:00
Jan Kara
599a9b77ab ext4: fix oops when loading block bitmap failed
When we fail to load block bitmap in __ext4_new_inode() we will
dereference NULL pointer in ext4_journal_get_write_access(). So check
for error from ext4_read_block_bitmap().

Coverity-id: 989065
Cc: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-30 10:53:16 -04:00
Jan Kara
9378c6768e ext4: fix overflow when updating superblock backups after resize
When there are no meta block groups update_backups() will compute the
backup block in 32-bit arithmetics thus possibly overflowing the block
number and corrupting the filesystem. OTOH filesystems without meta
block groups larger than 16 TB should be rare. Fix the problem by doing
the counting in 64-bit arithmetics.

Coverity-id: 741252
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
2014-10-30 10:52:57 -04:00
Linus Torvalds
a7ca10f263 Merge branch 'akpm' (incoming from Andrew Morton)
Merge misc fixes from Andrew Morton:
 "21 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (21 commits)
  mm/balloon_compaction: fix deflation when compaction is disabled
  sh: fix sh770x SCIF memory regions
  zram: avoid NULL pointer access in concurrent situation
  mm/slab_common: don't check for duplicate cache names
  ocfs2: fix d_splice_alias() return code checking
  mm: rmap: split out page_remove_file_rmap()
  mm: memcontrol: fix missed end-writeback page accounting
  mm: page-writeback: inline account_page_dirtied() into single caller
  lib/bitmap.c: fix undefined shift in __bitmap_shift_{left|right}()
  drivers/rtc/rtc-bq32k.c: fix register value
  memory-hotplug: clear pgdat which is allocated by bootmem in try_offline_node()
  drivers/rtc/rtc-s3c.c: fix initialization failure without rtc source clock
  kernel/kmod: fix use-after-free of the sub_info structure
  drivers/rtc/rtc-pm8xxx.c: rework to support pm8941 rtc
  mm, thp: fix collapsing of hugepages on madvise
  drivers: of: add return value to of_reserved_mem_device_init()
  mm: free compound page with correct order
  gcov: add ARM64 to GCOV_PROFILE_ALL
  fsnotify: next_i is freed during fsnotify_unmount_inodes.
  mm/compaction.c: avoid premature range skip in isolate_migratepages_range
  ...
2014-10-29 16:38:48 -07:00
Richard Weinberger
d3556babd7 ocfs2: fix d_splice_alias() return code checking
d_splice_alias() can return a valid dentry, NULL or an ERR_PTR.
Currently the code checks not for ERR_PTR and will cuase an oops in
ocfs2_dentry_attach_lock().  Fix this by using IS_ERR_OR_NULL().

Signed-off-by: Richard Weinberger <richard@nod.at>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-29 16:33:15 -07:00
Jerry Hoemann
6424babfd6 fsnotify: next_i is freed during fsnotify_unmount_inodes.
During file system stress testing on 3.10 and 3.12 based kernels, the
umount command occasionally hung in fsnotify_unmount_inodes in the
section of code:

                spin_lock(&inode->i_lock);
                if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) {
                        spin_unlock(&inode->i_lock);
                        continue;
                }

As this section of code holds the global inode_sb_list_lock, eventually
the system hangs trying to acquire the lock.

Multiple crash dumps showed:

The inode->i_state == 0x60 and i_count == 0 and i_sb_list would point
back at itself.  As this is not the value of list upon entry to the
function, the kernel never exits the loop.

To help narrow down problem, the call to list_del_init in
inode_sb_list_del was changed to list_del.  This poisons the pointers in
the i_sb_list and causes a kernel to panic if it transverse a freed
inode.

Subsequent stress testing paniced in fsnotify_unmount_inodes at the
bottom of the list_for_each_entry_safe loop showing next_i had become
free.

We believe the root cause of the problem is that next_i is being freed
during the window of time that the list_for_each_entry_safe loop
temporarily releases inode_sb_list_lock to call fsnotify and
fsnotify_inode_delete.

The code in fsnotify_unmount_inodes attempts to prevent the freeing of
inode and next_i by calling __iget.  However, the code doesn't do the
__iget call on next_i

	if i_count == 0 or
	if i_state & (I_FREEING | I_WILL_FREE)

The patch addresses this issue by advancing next_i in the above two cases
until we either find a next_i which we can __iget or we reach the end of
the list.  This makes the handling of next_i more closely match the
handling of the variable "inode."

The time to reproduce the hang is highly variable (from hours to days.) We
ran the stress test on a 3.10 kernel with the proposed patch for a week
without failure.

During list_for_each_entry_safe, next_i is becoming free causing
the loop to never terminate.  Advance next_i in those cases where
__iget is not done.

Signed-off-by: Jerry Hoemann <jerry.hoemann@hp.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Ken Helias <kenhelias@firemail.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-29 16:33:14 -07:00
Linus Torvalds
d506aa68c2 Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
 "A small collection of fixes for the current kernel.  This contains:

   - Two error handling fixes from Jan Kara.  One for null_blk on
     failure to add a device, and the other for the block/scsi_ioctl
     SCSI_IOCTL_SEND_COMMAND fixing up the error jump point.

   - A commit added in the merge window for the bio integrity bits
     unfortunately disabled merging for all requests if
     CONFIG_BLK_DEV_INTEGRITY wasn't set.  Reverse the logic, so that
     integrity checking wont disallow merges when not enabled.

   - A fix from Ming Lei for merging and generating too many segments.
     This caused a BUG in virtio_blk.

   - Two error handling printk() fixups from Robert Elliott, improving
     the information given when we rate limit.

   - Error handling fixup on elevator_init() failure from Sudip
     Mukherjee.

   - A fix from Tony Battersby, fixing up a memory leak in the
     scatterlist handling with scsi-mq"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: Fix merge logic when CONFIG_BLK_DEV_INTEGRITY is not defined
  lib/scatterlist: fix memory leak with scsi-mq
  block: fix wrong error return in elevator_init()
  scsi: Fix error handling in SCSI_IOCTL_SEND_COMMAND
  null_blk: Cleanup error recovery in null_add_dev()
  blk-merge: recaculate segment if it isn't less than max segments
  fs: clarify rate limit suppressed buffer I/O errors
  fs: merge I/O error prints into one line
2014-10-29 11:57:10 -07:00
Al Viro
f643ff550a isofs_cmp(): we'll never see a dentry for . or ..
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-28 18:37:40 -04:00
Miklos Szeredi
d1b72cc6d8 overlayfs: fix lockdep misannotation
In an overlay directory that shadows an empty lower directory, say
/mnt/a/empty102, do:

 	touch /mnt/a/empty102/x
 	unlink /mnt/a/empty102/x
 	rmdir /mnt/a/empty102

It's actually harmless, but needs another level of nesting between
I_MUTEX_CHILD and I_MUTEX_NORMAL.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-28 18:32:47 -04:00
Miklos Szeredi
c2096537d4 ovl: fix check for cursor
ovl_cache_entry.name is now an array not a pointer, so it makes no sense
test for it being NULL.

Detected by coverity.

From: Miklos Szeredi <mszeredi@suse.cz>
Fixes: 68bf861107 ("overlayfs: make ovl_cache_entry->name an array instead of
+pointer")
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-28 18:31:54 -04:00
Al Viro
d45f00ae43 overlayfs: barriers for opening upper-layer directory
make sure that
	a) all stores done by opening struct file don't leak past storing
the reference in od->upperfile
	b) the lockless side has read dependency barrier

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-28 18:27:28 -04:00
Filipe Manana
d05a2b4cd9 Btrfs: fix race that makes btrfs_lookup_extent_info miss skinny extent items
We have a race that can lead us to miss skinny extent items in the function
btrfs_lookup_extent_info() when the skinny metadata feature is enabled.
So basically the sequence of steps is:

1) We search in the extent tree for the skinny extent, which returns > 0
   (not found);

2) We check the previous item in the returned leaf for a non-skinny extent,
   and we don't find it;

3) Because we didn't find the non-skinny extent in step 2), we release our
   path to search the extent tree again, but this time for a non-skinny
   extent key;

4) Right after we released our path in step 3), a skinny extent was inserted
   in the extent tree (delayed refs were run) - our second extent tree search
   will miss it, because it's not looking for a skinny extent;

5) After the second search returned (with ret > 0), we look for any delayed
   ref for our extent's bytenr (and we do it while holding a read lock on the
   leaf), but we won't find any, as such delayed ref had just run and completed
   after we released out path in step 3) before doing the second search.

Fix this by removing completely the path release and re-search logic. This is
safe, because if we seach for a metadata item and we don't find it, we have the
guarantee that the returned leaf is the one where the item would be inserted,
and so path->slots[0] > 0 and path->slots[0] - 1 must be the slot where the
non-skinny extent item is if it exists. The only case where path->slots[0] is
zero is when there are no smaller keys in the tree (i.e. no left siblings for
our leaf), in which case the re-search logic isn't needed as well.

This race has been present since the introduction of skinny metadata (change
3173a18f70).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-10-28 13:59:54 -07:00
Linus Torvalds
9f76628da2 Merge branch 'for-3.18' of git://linux-nfs.org/~bfields/linux
Pull two nfsd fixes from Bruce Fields:
 "One regression from the 3.16 xdr rewrite, one an older bug exposed by
  a separate bug in the client's new SEEK code"

* 'for-3.18' of git://linux-nfs.org/~bfields/linux:
  nfsd4: fix crash on unknown operation number
  nfsd4: fix response size estimation for OP_SEQUENCE
2014-10-28 13:32:06 -07:00
Josef Bacik
5ed5f58841 Btrfs: properly clean up btrfs_end_io_wq_cache
In one of Dave's cleanup commits he forgot to call btrfs_end_io_wq_exit on
unload, which makes us unable to unload and then re-load the btrfs module.  This
fixes the problem.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-10-27 13:16:53 -07:00
Filipe Manana
1a4ed8fdca Btrfs: fix invalid leaf slot access in btrfs_lookup_extent()
If we couldn't find our extent item, we accessed the current slot
(path->slots[0]) to check if it corresponds to an equivalent skinny
metadata item. However this slot could be beyond our last item in the
leaf (i.e. path->slots[0] >= btrfs_header_nritems(leaf)), in which case
we shouldn't process it.

Since btrfs_lookup_extent() is only used to find extent items for data
extents, fix this by removing completely the logic that looks up for an
equivalent skinny metadata item, since it can not exist.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-10-27 13:16:52 -07:00
David Sterba
21e7626b12 btrfs: use macro accessors in superblock validation checks
The initial patch c926093ec5 (btrfs: add more superblock checks)
did not properly use the macro accessors that wrap endianness and the
code would not work correctly on big endian machines.

Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-10-27 13:16:52 -07:00
Linus Torvalds
d1e14f1d63 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "overlayfs merge + leak fix for d_splice_alias() failure exits"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  overlayfs: embed middle into overlay_readdir_data
  overlayfs: embed root into overlay_readdir_data
  overlayfs: make ovl_cache_entry->name an array instead of pointer
  overlayfs: don't hold ->i_mutex over opening the real directory
  fix inode leaks on d_splice_alias() failure exits
  fs: limit filesystem stacking depth
  overlay: overlay filesystem documentation
  overlayfs: implement show_options
  overlayfs: add statfs support
  overlay filesystem
  shmem: support RENAME_WHITEOUT
  ext4: support RENAME_WHITEOUT
  vfs: add RENAME_WHITEOUT
  vfs: add whiteout support
  vfs: export check_sticky()
  vfs: introduce clone_private_mount()
  vfs: export __inode_permission() to modules
  vfs: export do_splice_direct() to modules
  vfs: add i_op->dentry_open()
2014-10-26 11:19:18 -07:00
Al Viro
db6ec212b5 overlayfs: embed middle into overlay_readdir_data
same story...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-24 20:25:23 -04:00
Al Viro
49be4fb9cc overlayfs: embed root into overlay_readdir_data
no sense having it a pointer - all instances have it pointing to
local variable in the same stack frame

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-24 20:25:23 -04:00
Al Viro
68bf861107 overlayfs: make ovl_cache_entry->name an array instead of pointer
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-24 20:25:22 -04:00
Al Viro
3d268c9b13 overlayfs: don't hold ->i_mutex over opening the real directory
just use it to serialize the assignment

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-24 20:24:11 -04:00
Al Viro
1be47b387a Merge branch 'overlayfs.v25' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into for-linus 2014-10-23 22:52:55 -04:00
Al Viro
51486b900e fix inode leaks on d_splice_alias() failure exits
d_splice_alias() callers expect it to either stash the inode reference
into a new alias, or drop the inode reference.  That makes it possible
to just return d_splice_alias() result from ->lookup() instance, without
any extra housekeeping required.

Unfortunately, that should include the failure exits.  If d_splice_alias()
returns an error, it leaves the dentry it has been given negative and
thus it *must* drop the inode reference.  Easily fixed, but it goes way
back and will need backporting.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-23 22:30:18 -04:00
Miklos Szeredi
69c433ed2e fs: limit filesystem stacking depth
Add a simple read-only counter to super_block that indicates how deep this
is in the stack of filesystems.  Previously ecryptfs was the only stackable
filesystem and it explicitly disallowed multiple layers of itself.

Overlayfs, however, can be stacked recursively and also may be stacked
on top of ecryptfs or vice versa.

To limit the kernel stack usage we must limit the depth of the
filesystem stack.  Initially the limit is set to 2.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:39 +02:00
Erez Zadok
f45827e841 overlayfs: implement show_options
This is useful because of the stacking nature of overlayfs.  Users like to
find out (via /proc/mounts) which lower/upper directory were used at mount
time.

AV: even failing ovl_parse_opt() could've done some kstrdup()
AV: failure of ovl_alloc_entry() should end up with ENOMEM, not EINVAL

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:38 +02:00
Andy Whitcroft
cc2596392a overlayfs: add statfs support
Add support for statfs to the overlayfs filesystem.  As the upper layer
is the target of all write operations assume that the space in that
filesystem is the space in the overlayfs.  There will be some inaccuracy as
overwriting a file will copy it up and consume space we were not expecting,
but it is better than nothing.

Use the upper layer dentry and mount from the overlayfs root inode,
passing the statfs call to that filesystem.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:38 +02:00
Miklos Szeredi
e9be9d5e76 overlay filesystem
Overlayfs allows one, usually read-write, directory tree to be
overlaid onto another, read-only directory tree.  All modifications
go to the upper, writable layer.

This type of mechanism is most often used for live CDs but there's a
wide variety of other uses.

The implementation differs from other "union filesystem"
implementations in that after a file is opened all operations go
directly to the underlying, lower or upper, filesystems.  This
simplifies the implementation and allows native performance in these
cases.

The dentry tree is duplicated from the underlying filesystems, this
enables fast cached lookups without adding special support into the
VFS.  This uses slightly more memory than union mounts, but dentries
are relatively small.

Currently inodes are duplicated as well, but it is a possible
optimization to share inodes for non-directories.

Opening non directories results in the open forwarded to the
underlying filesystem.  This makes the behavior very similar to union
mounts (with the same limitations vs. fchmod/fchown on O_RDONLY file
descriptors).

Usage:

  mount -t overlayfs overlayfs -olowerdir=/lower,upperdir=/upper/upper,workdir=/upper/work /overlay

The following cotributions have been folded into this patch:

Neil Brown <neilb@suse.de>:
 - minimal remount support
 - use correct seek function for directories
 - initialise is_real before use
 - rename ovl_fill_cache to ovl_dir_read

Felix Fietkau <nbd@openwrt.org>:
 - fix a deadlock in ovl_dir_read_merged
 - fix a deadlock in ovl_remove_whiteouts

Erez Zadok <ezk@fsl.cs.sunysb.edu>
 - fix cleanup after WARN_ON

Sedat Dilek <sedat.dilek@googlemail.com>
 - fix up permission to confirm to new API

Robin Dong <hao.bigrat@gmail.com>
 - fix possible leak in ovl_new_inode
 - create new inode in ovl_link

Andy Whitcroft <apw@canonical.com>
 - switch to __inode_permission()
 - copy up i_uid/i_gid from the underlying inode

AV:
 - ovl_copy_up_locked() - dput(ERR_PTR(...)) on two failure exits
 - ovl_clear_empty() - one failure exit forgetting to do unlock_rename(),
   lack of check for udir being the parent of upper, dropping and regaining
   the lock on udir (which would require _another_ check for parent being
   right).
 - bogus d_drop() in copyup and rename [fix from your mail]
 - copyup/remove and copyup/rename races [fix from your mail]
 - ovl_dir_fsync() leaving ERR_PTR() in ->realfile
 - ovl_entry_free() is pointless - it's just a kfree_rcu()
 - fold ovl_do_lookup() into ovl_lookup()
 - manually assigning ->d_op is wrong.  Just use ->s_d_op.
 [patches picked from Miklos]:
 * copyup/remove and copyup/rename races
 * bogus d_drop() in copyup and rename

Also thanks to the following people for testing and reporting bugs:

  Jordi Pujol <jordipujolp@gmail.com>
  Andy Whitcroft <apw@canonical.com>
  Michal Suchanek <hramrach@centrum.cz>
  Felix Fietkau <nbd@openwrt.org>
  Erez Zadok <ezk@fsl.cs.sunysb.edu>
  Randy Dunlap <rdunlap@xenotime.net>

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:38 +02:00
Miklos Szeredi
cd808deced ext4: support RENAME_WHITEOUT
Add whiteout support to ext4_rename().  A whiteout inode (chrdev/0,0) is
created before the rename takes place.  The whiteout inode is added to the
old entry instead of deleting it.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:37 +02:00
Miklos Szeredi
0d7a855526 vfs: add RENAME_WHITEOUT
This adds a new RENAME_WHITEOUT flag.  This flag makes rename() create a
whiteout of source.  The whiteout creation is atomic relative to the
rename.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:37 +02:00
Miklos Szeredi
787fb6bc96 vfs: add whiteout support
Whiteout isn't actually a new file type, but is represented as a char
device (Linus's idea) with 0/0 device number.

This has several advantages compared to introducing a new whiteout file
type:

 - no userspace API changes (e.g. trivial to make backups of upper layer
   filesystem, without losing whiteouts)

 - no fs image format changes (you can boot an old kernel/fsck without
   whiteout support and things won't break)

 - implementation is trivial

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:36 +02:00
Miklos Szeredi
cbdf35bcb8 vfs: export check_sticky()
It's already duplicated in btrfs and about to be used in overlayfs too.

Move the sticky bit check to an inline helper and call the out-of-line
helper only in the unlikly case of the sticky bit being set.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:36 +02:00
Miklos Szeredi
c771d683a6 vfs: introduce clone_private_mount()
Overlayfs needs a private clone of the mount, so create a function for
this and export to modules.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:36 +02:00
Miklos Szeredi
bd5d08569c vfs: export __inode_permission() to modules
We need to be able to check inode permissions (but not filesystem implied
permissions) for stackable filesystems.  Expose this interface for overlayfs.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:35 +02:00
Miklos Szeredi
1c118596a7 vfs: export do_splice_direct() to modules
Export do_splice_direct() to modules.  Needed by overlay filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:35 +02:00
Miklos Szeredi
4aa7c6346b vfs: add i_op->dentry_open()
Add a new inode operation i_op->dentry_open().  This is for stacked filesystems
that want to return a struct file from a different filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:35 +02:00