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| author | Al Viro <viro@zeniv.linux.org.uk> | 2014-02-09 15:18:09 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2014-02-09 15:18:09 -0500 |
| commit | d311d79de305f1ada47cadd672e6ed1b28a949eb (patch) | |
| tree | ed5fe40264a27e1d8cc4410352585dfb34af50d8 /fs/cifs | |
| parent | 38dbfb59d1175ef458d006556061adeaa8751b72 (diff) | |
| download | linux-d311d79de305f1ada47cadd672e6ed1b28a949eb.tar.gz linux-d311d79de305f1ada47cadd672e6ed1b28a949eb.tar.bz2 linux-d311d79de305f1ada47cadd672e6ed1b28a949eb.zip | |
fix O_SYNC|O_APPEND syncing the wrong range on write()
It actually goes back to 2004 ([PATCH] Concurrent O_SYNC write support)
when sync_page_range() had been introduced; generic_file_write{,v}() correctly
synced
pos_after_write - written .. pos_after_write - 1
but generic_file_aio_write() synced
pos_before_write .. pos_before_write + written - 1
instead. Which is not the same thing with O_APPEND, obviously.
A couple of years later correct variant had been killed off when
everything switched to use of generic_file_aio_write().
All users of generic_file_aio_write() are affected, and the same bug
has been copied into other instances of ->aio_write().
The fix is trivial; the only subtle point is that generic_write_sync()
ought to be inlined to avoid calculations useless for the majority of
calls.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/cifs')
| -rw-r--r-- | fs/cifs/file.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 853d6d1cc822..a7eda8ebfacc 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2559,8 +2559,8 @@ cifs_writev(struct kiocb *iocb, const struct iovec *iov, if (rc > 0) { ssize_t err; - err = generic_write_sync(file, pos, rc); - if (err < 0 && rc > 0) + err = generic_write_sync(file, iocb->ki_pos - rc, rc); + if (err < 0) rc = err; } |