fs: fix fsync() error reporting
authorDmitry Monakhov <dmonakhov@openvz.org>
Mon, 29 Apr 2013 22:08:42 +0000 (15:08 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 29 Apr 2013 22:54:38 +0000 (15:54 -0700)
commit865ffef3797da2cac85b3354b5b6050dc9660978
tree831324f5fe5b1f0ed91318f5de7669045f4f941e
parent209ff86d61d6b50979cffb47878fc77ca2f6c8a2
fs: fix fsync() error reporting

There are two convenient ways to report errors to userspace

1) retun error to original syscall for example write(2)
2) mark mapping with error flag and return it on later fsync(2)

Second one is broken if (mapping->nrpages == 0) This is real-life
situation because after error pages are likey to be truncated or
invalidated.

We have to return an error regardless to number of pages in the mapping.

#Original testcase: git@github.com:dmonakhov/xfstests.git
MOUNT_OPTIONS="-b1024"
./check shared/305

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/filemap.c