From: Xiubo Li xiubli@redhat.com
[ Upstream commit 1065da21e5df9d843d2c5165d5d576be000142a6 ]
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: c3d8e0b5de48 ("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 --- fs/ceph/file.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/fs/ceph/file.c b/fs/ceph/file.c index b5f8038065d7c..bdd0a3b894b7b 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -1108,7 +1108,12 @@ 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;
@@ -1137,15 +1142,13 @@ 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)