From 1065da21e5df9d843d2c5165d5d576be000142a6 Mon Sep 17 00:00:00 2001 From: Xiubo Li Date: Wed, 21 Feb 2024 09:16:12 +0800 Subject: [PATCH] ceph: stop copying to iter at EOF on sync reads 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 Signed-off-by: Xiubo Li Reviewed-by: Ilya Dryomov Tested-by: Frank Hsiao Signed-off-by: Ilya Dryomov --- 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 abe8028d95bf..3d1cd079dbf1 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -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)