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  1. 27 10月, 2017 22 次提交
  3. 25 10月, 2017 1 次提交
  5. 24 10月, 2017 1 次提交
  7. 20 10月, 2017 1 次提交
    • M
      membarrier: Provide register expedited private command · a961e409
      由 Mathieu Desnoyers 提交于 
      This introduces a "register private expedited" membarrier command which
allows eventual removal of important memory barrier constraints on the
scheduler fast-paths. It changes how the "private expedited" membarrier
command (new to 4.14) is used from user-space.

This new command allows processes to register their intent to use the
private expedited command.  This affects how the expedited private
command introduced in 4.14-rc is meant to be used, and should be merged
before 4.14 final.

Processes are now required to register before using
MEMBARRIER_CMD_PRIVATE_EXPEDITED, otherwise that command returns EPERM.

This fixes a problem that arose when designing requested extensions to
sys_membarrier() to allow JITs to efficiently flush old code from
instruction caches.  Several potential algorithms are much less painful
if the user register intent to use this functionality early on, for
example, before the process spawns the second thread.  Registering at
this time removes the need to interrupt each and every thread in that
process at the first expedited sys_membarrier() system call.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a961e409
  9. 19 10月, 2017 1 次提交
  11. 17 10月, 2017 6 次提交
    • L
      fs: Avoid invalidation in interrupt context in dio_complete() · ffe51f01
      由 Lukas Czerner 提交于 
      Currently we try to defer completion of async DIO to the process context
in case there are any mapped pages associated with the inode so that we
can invalidate the pages when the IO completes. However the check is racy
and the pages can be mapped afterwards. If this happens we might end up
calling invalidate_inode_pages2_range() in dio_complete() in interrupt
context which could sleep. This can be reproduced by generic/451.

Fix this by passing the information whether we can or can't invalidate
to the dio_complete(). Thanks Eryu Guan for reporting this and Jan Kara
for suggesting a fix.

Fixes: 332391a9 ("fs: Fix page cache inconsistency when mixing buffered and AIO DIO")
Reported-by: NEryu Guan <eguan@redhat.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Tested-by: NEryu Guan <eguan@redhat.com>
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      ffe51f01
    • M
      vfs: fix mounting a filesystem with i_version · 917086ff
      由 Mimi Zohar 提交于 
      The mount i_version flag is not enabled in the new sb_flags.  This patch
adds the missing SB_I_VERSION flag.

Fixes: e462ec50 "VFS: Differentiate mount flags (MS_*) from internal
       superblock flags"
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      917086ff
    • A
      xfs: move two more RT specific functions into CONFIG_XFS_RT · 785545c8
      由 Arnd Bergmann 提交于 
      The last cleanup introduced two harmless warnings:

fs/xfs/xfs_fsmap.c:480:1: warning: '__xfs_getfsmap_rtdev' defined but not used
fs/xfs/xfs_fsmap.c:372:1: warning: 'xfs_getfsmap_rtdev_rtbitmap_helper' defined but not used

This moves those two functions as well.

Fixes: bb9c2e54 ("xfs: move more RT specific code under CONFIG_XFS_RT")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      785545c8
    • B
      xfs: trim writepage mapping to within eof · 40214d12
      由 Brian Foster 提交于 
      The writeback rework in commit fbcc0256 ("xfs: Introduce
writeback context for writepages") introduced a subtle change in
behavior with regard to the block mapping used across the
->writepages() sequence. The previous xfs_cluster_write() code would
only flush pages up to EOF at the time of the writepage, thus
ensuring that any pages due to file-extending writes would be
handled on a separate cycle and with a new, updated block mapping.

The updated code establishes a block mapping in xfs_writepage_map()
that could extend beyond EOF if the file has post-eof preallocation.
Because we now use the generic writeback infrastructure and pass the
cached mapping to each writepage call, there is no implicit EOF
limit in place. If eofblocks trimming occurs during ->writepages(),
any post-eof portion of the cached mapping becomes invalid. The
eofblocks code has no means to serialize against writeback because
there are no pages associated with post-eof blocks. Therefore if an
eofblocks trim occurs and is followed by a file-extending buffered
write, not only has the mapping become invalid, but we could end up
writing a page to disk based on the invalid mapping.

Consider the following sequence of events:

- A buffered write creates a delalloc extent and post-eof
  speculative preallocation.
- Writeback starts and on the first writepage cycle, the delalloc
  extent is converted to real blocks (including the post-eof blocks)
  and the mapping is cached.
- The file is closed and xfs_release() trims post-eof blocks. The
  cached writeback mapping is now invalid.
- Another buffered write appends the file with a delalloc extent.
- The concurrent writeback cycle picks up the just written page
  because the writeback range end is LLONG_MAX. xfs_writepage_map()
  attributes it to the (now invalid) cached mapping and writes the
  data to an incorrect location on disk (and where the file offset is
  still backed by a delalloc extent).

This problem is reproduced by xfstests test generic/464, which
triggers racing writes, appends, open/closes and writeback requests.

To address this problem, trim the mapping used during writeback to
within EOF when the mapping is validated. This ensures the mapping
is revalidated for any pages encountered beyond EOF as of the time
the current mapping was cached or last validated.
Reported-by: NEryu Guan <eguan@redhat.com>
Diagnosed-by: NEryu Guan <eguan@redhat.com>
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      40214d12
    • E
      fs: invalidate page cache after end_io() in dio completion · 5e25c269
      由 Eryu Guan 提交于 
      Commit 332391a9 ("fs: Fix page cache inconsistency when mixing
buffered and AIO DIO") moved page cache invalidation from
iomap_dio_rw() to iomap_dio_complete() for iomap based direct write
path, but before the dio->end_io() call, and it re-introdued the bug
fixed by commit c771c14b ("iomap: invalidate page caches should
be after iomap_dio_complete() in direct write").

I found this because fstests generic/418 started failing on XFS with
v4.14-rc3 kernel, which is the regression test for this specific
bug.

So similarly, fix it by moving dio->end_io() (which does the
unwritten extent conversion) before page cache invalidation, to make
sure next buffer read reads the final real allocations not unwritten
extents. I also add some comments about why should end_io() go first
in case we get it wrong again in the future.

Note that, there's no such problem in the non-iomap based direct
write path, because we didn't remove the page cache invalidation
after the ->direct_IO() in generic_file_direct_write() call, but I
decided to fix dio_complete() too so we don't leave a landmine
there, also be consistent with iomap_dio_complete().

Fixes: 332391a9 ("fs: Fix page cache inconsistency when mixing buffered and AIO DIO")
Signed-off-by: NEryu Guan <eguan@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>
      5e25c269
    • D
      xfs: cancel dirty pages on invalidation · 793d7dbe
      由 Dave Chinner 提交于 
      Recently we've had warnings arise from the vm handing us pages
without bufferheads attached to them. This should not ever occur
in XFS, but we don't defend against it properly if it does. The only
place where we remove bufferheads from a page is in
xfs_vm_releasepage(), but we can't tell the difference here between
"page is dirty so don't release" and "page is dirty but is being
invalidated so release it".

In some places that are invalidating pages ask for pages to be
released and follow up afterward calling ->releasepage by checking
whether the page was dirty and then aborting the invalidation. This
is a possible vector for releasing buffers from a page but then
leaving it in the mapping, so we really do need to avoid dirty pages
in xfs_vm_releasepage().

To differentiate between invalidated pages and normal pages, we need
to clear the page dirty flag when invalidating the pages. This can
be done through xfs_vm_invalidatepage(), and will result
xfs_vm_releasepage() seeing the page as clean which matches the
bufferhead state on the page after calling block_invalidatepage().

Hence we can re-add the page dirty check in xfs_vm_releasepage to
catch the case where we might be releasing a page that is actually
dirty and so should not have the bufferheads on it removed. This
will remove one possible vector of "dirty page with no bufferheads"
and so help narrow down the search for the root cause of that
problem.
Signed-Off-By: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      793d7dbe
  13. 14 10月, 2017 2 次提交
  15. 13 10月, 2017 3 次提交
    • E
      ecryptfs: fix dereference of NULL user_key_payload · f66665c0
      由 Eric Biggers 提交于 
      In eCryptfs, we failed to verify that the authentication token keys are
not revoked before dereferencing their payloads, which is problematic
because the payload of a revoked key is NULL.  request_key() *does* skip
revoked keys, but there is still a window where the key can be revoked
before we acquire the key semaphore.

Fix it by updating ecryptfs_get_key_payload_data() to return
-EKEYREVOKED if the key payload is NULL.  For completeness we check this
for "encrypted" keys as well as "user" keys, although encrypted keys
cannot be revoked currently.

Alternatively we could use key_validate(), but since we'll also need to
fix ecryptfs_get_key_payload_data() to validate the payload length, it
seems appropriate to just check the payload pointer.

Fixes: 237fead6 ("[PATCH] ecryptfs: fs/Makefile and fs/Kconfig")
Reviewed-by: NJames Morris <james.l.morris@oracle.com>
Cc: <stable@vger.kernel.org>    [v2.6.19+]
Cc: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
      f66665c0
    • E
      fscrypt: fix dereference of NULL user_key_payload · d60b5b78
      由 Eric Biggers 提交于 
      When an fscrypt-encrypted file is opened, we request the file's master
key from the keyrings service as a logon key, then access its payload.
However, a revoked key has a NULL payload, and we failed to check for
this.  request_key() *does* skip revoked keys, but there is still a
window where the key can be revoked before we acquire its semaphore.

Fix it by checking for a NULL payload, treating it like a key which was
already revoked at the time it was requested.

Fixes: 88bd6ccd ("ext4 crypto: add encryption key management facilities")
Reviewed-by: NJames Morris <james.l.morris@oracle.com>
Cc: <stable@vger.kernel.org>    [v4.1+]
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
      d60b5b78
    • E
      FS-Cache: fix dereference of NULL user_key_payload · d124b2c5
      由 Eric Biggers 提交于 
      When the file /proc/fs/fscache/objects (available with
CONFIG_FSCACHE_OBJECT_LIST=y) is opened, we request a user key with
description "fscache:objlist", then access its payload.  However, a
revoked key has a NULL payload, and we failed to check for this.
request_key() *does* skip revoked keys, but there is still a window
where the key can be revoked before we access its payload.

Fix it by checking for a NULL payload, treating it like a key which was
already revoked at the time it was requested.

Fixes: 4fbf4291 ("FS-Cache: Allow the current state of all objects to be dumped")
Reviewed-by: NJames Morris <james.l.morris@oracle.com>
Cc: <stable@vger.kernel.org>    [v2.6.32+]
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
      d124b2c5
  17. 12 10月, 2017 3 次提交