ceph: stop copying to iter at EOF on sync reads

[ Upstream commit 1065da21e5 ]

If EOF is encountered, ceph_sync_read() return value is adjusted down
according to i_size, but the "to" iter is advanced by the actual number
of bytes read.  Then, when retrying, the remainder of the range may be
skipped incorrectly.

Ensure that the "to" iter is advanced only until EOF.

[ idryomov: changelog ]

Fixes: c3d8e0b5de ("ceph: return the real size read when it hits EOF")
Reported-by: Frank Hsiao <frankhsiao@qnap.com>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Frank Hsiao <frankhsiao@qnap.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Xiubo Li 2024-02-21 09:16:12 +08:00 committed by Sasha Levin
parent b15bce1666
commit 834c93dcef
1 changed files with 13 additions and 10 deletions

View File

@ -1138,7 +1138,12 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos,
}
idx = 0;
left = ret > 0 ? ret : 0;
if (ret <= 0)
left = 0;
else if (off + ret > i_size)
left = i_size - off;
else
left = ret;
while (left > 0) {
size_t plen, copied;
@ -1167,15 +1172,13 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos,
}
if (ret > 0) {
if (off > *ki_pos) {
if (off >= i_size) {
*retry_op = CHECK_EOF;
ret = i_size - *ki_pos;
*ki_pos = i_size;
} else {
ret = off - *ki_pos;
*ki_pos = off;
}
if (off >= i_size) {
*retry_op = CHECK_EOF;
ret = i_size - *ki_pos;
*ki_pos = i_size;
} else {
ret = off - *ki_pos;
*ki_pos = off;
}
if (last_objver)