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  1. 14 12月, 2014 1 次提交
    • H
      fallocate: create FAN_MODIFY and IN_MODIFY events · 820c12d5
      由 Heinrich Schuchardt 提交于 
      The fanotify and the inotify API can be used to monitor changes of the
file system.  System call fallocate() modifies files.  Hence it should
trigger the corresponding fanotify (FAN_MODIFY) and inotify (IN_MODIFY)
events.  The most interesting case is FALLOC_FL_COLLAPSE_RANGE because
this value allows to create arbitrary file content from random data.

This patch adds the missing call to fsnotify_modify().

The FAN_MODIFY and IN_MODIFY event will be created when fallocate()
succeeds.  It will even be created if the file length remains unchanged,
e.g.  when calling fanotify with flag FALLOC_FL_KEEP_SIZE.

This logic was primarily chosen to keep the coding simple.

It resembles the logic of the write() system call.

When we call write() we always create a FAN_MODIFY event, even in the case
of overwriting with identical data.

Events FAN_MODIFY and IN_MODIFY do not provide any guarantee that data was
actually changed.

Furthermore even if if the filesize remains unchanged, fallocate() may
influence whether a subsequent write() will succeed and hence the
fallocate() call may be considered a modification.

The fallocate(2) man page teaches: After a successful call, subsequent
writes into the range specified by offset and len are guaranteed not to
fail because of lack of disk space.

So calling fallocate(fd, FALLOC_FL_KEEP_SIZE, offset, len) may result in
different outcomes of a subsequent write depending on the values of offset
and len.
Signed-off-by: NHeinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@parisplace.org>
Cc: John McCutchan <john@johnmccutchan.com>
Cc: Robert Love <rlove@rlove.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      820c12d5
  3. 20 11月, 2014 1 次提交
    • A
      new helper: audit_file() · 9f45f5bf
      由 Al Viro 提交于 
      ... for situations when we don't have any candidate in pathnames - basically,
in descriptor-based syscalls.

[Folded the build fix for !CONFIG_AUDITSYSCALL configs from Chen Gang]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      9f45f5bf
  5. 08 11月, 2014 1 次提交
  7. 24 10月, 2014 1 次提交
  9. 01 8月, 2014 1 次提交
  11. 07 5月, 2014 2 次提交
    • A
      new methods: ->read_iter() and ->write_iter() · 293bc982
      由 Al Viro 提交于 
      Beginning to introduce those.  Just the callers for now, and it's
clumsier than it'll eventually become; once we finish converting
aio_read and aio_write instances, the things will get nicer.

For now, these guys are in parallel to ->aio_read() and ->aio_write();
they take iocb and iov_iter, with everything in iov_iter already
validated.  File offset is passed in iocb->ki_pos, iov/nr_segs -
in iov_iter.

Main concerns in that series are stack footprint and ability to
split the damn thing cleanly.

[fix from Peter Ujfalusi <peter.ujfalusi@ti.com> folded]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      293bc982
    • A
      replace checking for ->read/->aio_read presence with check in ->f_mode · 7f7f25e8
      由 Al Viro 提交于 
      Since we are about to introduce new methods (read_iter/write_iter), the
tests in a bunch of places would have to grow inconveniently.  Check
once (at open() time) and store results in ->f_mode as FMODE_CAN_READ
and FMODE_CAN_WRITE resp.  It might end up being a temporary measure -
once everything switches from ->aio_{read,write} to ->{read,write}_iter
it might make sense to return to open-coded checks.  We'll see...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      7f7f25e8
  13. 12 4月, 2014 3 次提交
  15. 02 4月, 2014 5 次提交
  17. 13 3月, 2014 1 次提交
    • L
      fs: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate · 409332b6
      由 Lukas Czerner 提交于 
      Introduce new FALLOC_FL_ZERO_RANGE flag for fallocate. This has the same
functionality as xfs ioctl XFS_IOC_ZERO_RANGE.

It can be used to convert a range of file to zeros preferably without
issuing data IO. Blocks should be preallocated for the regions that span
holes in the file, and the entire range is preferable converted to
unwritten extents - even though file system may choose to zero out the
extent or do whatever which will result in reading zeros from the range
while the range remains allocated for the file.

This can be also used to preallocate blocks past EOF in the same way as
with fallocate. Flag FALLOC_FL_KEEP_SIZE which should cause the inode
size to remain the same.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>
      409332b6
  19. 10 3月, 2014 1 次提交
    • L
      vfs: atomic f_pos accesses as per POSIX · 9c225f26
      由 Linus Torvalds 提交于 
      Our write() system call has always been atomic in the sense that you get
the expected thread-safe contiguous write, but we haven't actually
guaranteed that concurrent writes are serialized wrt f_pos accesses, so
threads (or processes) that share a file descriptor and use "write()"
concurrently would quite likely overwrite each others data.

This violates POSIX.1-2008/SUSv4 Section XSI 2.9.7 that says:

 "2.9.7 Thread Interactions with Regular File Operations

  All of the following functions shall be atomic with respect to each
  other in the effects specified in POSIX.1-2008 when they operate on
  regular files or symbolic links: [...]"

and one of the effects is the file position update.

This unprotected file position behavior is not new behavior, and nobody
has ever cared.  Until now.  Yongzhi Pan reported unexpected behavior to
Michael Kerrisk that was due to this.

This resolves the issue with a f_pos-specific lock that is taken by
read/write/lseek on file descriptors that may be shared across threads
or processes.
Reported-by: NYongzhi Pan <panyongzhi@gmail.com>
Reported-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      9c225f26
  21. 24 2月, 2014 1 次提交
  23. 09 11月, 2013 2 次提交
  25. 25 10月, 2013 1 次提交
  27. 17 9月, 2013 1 次提交
    • M
      vfs: improve i_op->atomic_open() documentation · 0854d450
      由 Miklos Szeredi 提交于 
      Fix documentation of ->atomic_open() and related functions: finish_open()
and finish_no_open().  Also add details that seem to be unclear and a
source of bugs (some of which are fixed in the following series).

Cc-ing maintainers of all filesystems implementing ->atomic_open().
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Steve French <sfrench@samba.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      0854d450
  29. 04 9月, 2013 1 次提交
  31. 31 8月, 2013 1 次提交
  33. 05 8月, 2013 1 次提交
  35. 20 7月, 2013 1 次提交
  37. 13 7月, 2013 1 次提交
    • A
      Safer ABI for O_TMPFILE · bb458c64
      由 Al Viro 提交于 
      [suggested by Rasmus Villemoes] make O_DIRECTORY | O_RDWR part of O_TMPFILE;
that will fail on old kernels in a lot more cases than what I came up with.
And make sure O_CREAT doesn't get there...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      bb458c64
  39. 29 6月, 2013 2 次提交
  41. 04 3月, 2013 2 次提交
  43. 02 3月, 2013 1 次提交
  45. 26 2月, 2013 1 次提交
  47. 25 2月, 2013 1 次提交
  49. 23 2月, 2013 2 次提交
  51. 21 12月, 2012 4 次提交