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Filipe Manana 0d836392ca Btrfs: fix mount failure after fsync due to hard link recreation
If we end up with logging an inode reference item which has the same name
but different index from the one we have persisted, we end up failing when
replaying the log with an errno value of -EEXIST. The error comes from
btrfs_add_link(), which is called from add_inode_ref(), when we are
replaying an inode reference item.

Example scenario where this happens:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ touch /mnt/foo
  $ ln /mnt/foo /mnt/bar

  $ sync

  # Rename the first hard link (foo) to a new name and rename the second
  # hard link (bar) to the old name of the first hard link (foo).
  $ mv /mnt/foo /mnt/qwerty
  $ mv /mnt/bar /mnt/foo

  # Create a new file, in the same parent directory, with the old name of
  # the second hard link (bar) and fsync this new file.
  # We do this instead of calling fsync on foo/qwerty because if we did
  # that the fsync resulted in a full transaction commit, not triggering
  # the problem.
  $ touch /mnt/bar
  $ xfs_io -c "fsync" /mnt/bar

  <power fail>

  $ mount /dev/sdb /mnt
  mount: mount /dev/sdb on /mnt failed: File exists

So fix this by checking if a conflicting inode reference exists (same
name, same parent but different index), removing it (and the associated
dir index entries from the parent inode) if it exists, before attempting
to add the new reference.

A test case for fstests follows soon.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:59 +02:00
arch Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-05 09:39:30 -07:00
block Partially revert "block: fail op_is_write() requests to read-only partitions" 2018-08-04 18:19:55 -07:00
certs certs/blacklist: fix const confusion 2018-06-26 09:43:03 -07:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-07-19 07:32:44 -07:00
Documentation Documentation: dpaa2: Use correct heading adornment 2018-08-01 09:45:57 -07:00
drivers Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-08-05 08:20:39 -07:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Btrfs: fix mount failure after fsync due to hard link recreation 2018-08-06 13:12:59 +02:00
include btrfs: Get rid of the confusing btrfs_file_extent_inline_len 2018-08-06 13:12:38 +02:00
init Kbuild fixes for v4.18 2018-06-30 13:05:30 -07:00
ipc ipc/shm.c add ->pagesize function to shm_vm_ops 2018-08-02 16:03:40 -07:00
kernel Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-05 09:25:29 -07:00
lib kasan: only select SLUB_DEBUG with SYSFS=y 2018-07-26 19:38:03 -07:00
LICENSES LICENSES: Add Linux-OpenIB license text 2018-04-27 16:41:53 -06:00
mm ipc/shm.c add ->pagesize function to shm_vm_ops 2018-08-02 16:03:40 -07:00
net netlink: Don't shift on 64 for ngroups 2018-08-04 17:52:51 -07:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-07-18 19:32:54 -07:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-07-18 19:32:54 -07:00
security selinux/stable-4.18 PR 20180629 2018-06-30 11:15:12 -07:00
sound ALSA: hda/realtek - Yet another Clevo P950 quirk entry 2018-07-18 12:17:46 +02:00
tools Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-05 09:13:07 -07:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt Miscellaneous bugfixes, plus a small patchlet related to Spectre v2. 2018-07-18 11:08:44 -07:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap Merge branch 'asoc-4.17' into asoc-4.18 for compress dependencies 2018-04-26 12:24:28 +01:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: add basic helper macros to scripts/Kconfig.include 2018-05-29 03:31:19 +09:00
MAINTAINERS ARC updates for 4.18 2018-08-02 16:52:50 -07:00
Makefile Linux 4.18-rc8 2018-08-05 12:37:41 -07:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.