[PATCH 3.16 116/346] ceph: Correctly return NXIO errors from ceph_llseek

From: Ben Hutchings
Date: Sun Nov 13 2016 - 22:40:38 EST


3.16.39-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Phil Turnbull <phil.turnbull@xxxxxxxxxx>

commit 955818cd5b6c4b58ea574ace4573e7afa4c19c1e upstream.

ceph_llseek does not correctly return NXIO errors because the 'out' path
always returns 'offset'.

Fixes: 06222e491e66 ("fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek")
Signed-off-by: Phil Turnbull <phil.turnbull@xxxxxxxxxx>
Signed-off-by: Yan, Zheng <zyan@xxxxxxxxxx>
[bwh: Backported to 3.16; adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
fs/ceph/file.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)

--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -985,16 +985,14 @@ out_unlocked:
static loff_t ceph_llseek(struct file *file, loff_t offset, int whence)
{
struct inode *inode = file->f_mapping->host;
- int ret;
+ loff_t ret;

mutex_lock(&inode->i_mutex);

if (whence == SEEK_END || whence == SEEK_DATA || whence == SEEK_HOLE) {
ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE);
- if (ret < 0) {
- offset = ret;
+ if (ret < 0)
goto out;
- }
}

switch (whence) {
@@ -1009,7 +1007,7 @@ static loff_t ceph_llseek(struct file *f
* write() or lseek() might have altered it
*/
if (offset == 0) {
- offset = file->f_pos;
+ ret = file->f_pos;
goto out;
}
offset += file->f_pos;
@@ -1029,11 +1027,11 @@ static loff_t ceph_llseek(struct file *f
break;
}

- offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
+ ret = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);

out:
mutex_unlock(&inode->i_mutex);
- return offset;
+ return ret;
}

static inline void ceph_zero_partial_page(