diff options
| author | Brian Behlendorf <[email protected]> | 2015-02-20 10:28:25 -0800 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2015-02-24 11:21:54 -0800 |
| commit | 1efdc45ea805e61de2c54736cd1b2a4a5f48a913 (patch) | |
| tree | 864346e155a41ce191030482021f8545db1a877c /module/zfs/zpl_file.c | |
| parent | 1d966336f5095c7e0345360c3862577642670d2d (diff) | |
Fix O_APPEND open(2) flag
As described in flags section of open(2):
O_APPEND:
The file is opened in append mode. Before each write(2), the
file offset is positioned at the end of the file, as if with
lseek(2). O_APPEND may lead to corrupted files on NFS filesys-
tems if more than one process appends data to a file at once.
This is because NFS does not support appending to a file, so the
client kernel has to simulate it, which can't be done without a
race condition.
This issue was originally overlooked because normally the generic
VFS code handles this for a filesystem. However, because ZFS explictly
registers a zpl_write() function it's responsible for the seek.
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #3124
Diffstat (limited to 'module/zfs/zpl_file.c')
| -rw-r--r-- | module/zfs/zpl_file.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/module/zfs/zpl_file.c b/module/zfs/zpl_file.c index 5f5bbba3d..571e04315 100644 --- a/module/zfs/zpl_file.c +++ b/module/zfs/zpl_file.c @@ -272,6 +272,9 @@ zpl_write_common_iovec(struct inode *ip, const struct iovec *iovp, size_t count, uio_t uio; int error; + if (flags & O_APPEND) + *ppos = i_size_read(ip); + uio.uio_iov = (struct iovec *)iovp; uio.uio_resid = count; uio.uio_iovcnt = nr_segs; |