This patch refines the read logic in __ceph_sync_read() to ensure more predictable and efficient behavior in various edge cases. - Return early if the requested read length is zero or if the file size (`i_size`) is zero. - Initialize the index variable (`idx`) where needed and reorder some code to ensure it is always set before use. - Improve error handling by checking for negative return values earlier. - Remove redundant encrypted file checks after failures. Only attempt filesystem-level decryption if the read succeeded. - Simplify leftover calculations to correctly handle cases where the read extends beyond the end of the file or stops short. - This resolves multiple issues caused by integer overflow - https://tracker.ceph.com/issues/67524 - https://tracker.ceph.com/issues/68981 - https://tracker.ceph.com/issues/68980 Signed-off-by: Alex Markuze <amarkuze@xxxxxxxxxx> --- fs/ceph/file.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) diff --git a/fs/ceph/file.c b/fs/ceph/file.c index ce342a5d4b8b..8e0400d461a2 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -1066,7 +1066,7 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos, if (ceph_inode_is_shutdown(inode)) return -EIO; - if (!len) + if (!len || !i_size) return 0; /* * flush any page cache pages in this range. this @@ -1086,7 +1086,7 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos, int num_pages; size_t page_off; bool more; - int idx; + int idx = 0; size_t left; struct ceph_osd_req_op *op; u64 read_off = off; @@ -1160,7 +1160,14 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos, else if (ret == -ENOENT) ret = 0; - if (ret > 0 && IS_ENCRYPTED(inode)) { + if (ret < 0) { + ceph_osdc_put_request(req); + if (ret == -EBLOCKLISTED) + fsc->blocklisted = true; + break; + } + + if (IS_ENCRYPTED(inode)) { int fret; fret = ceph_fscrypt_decrypt_extents(inode, pages, @@ -1187,7 +1194,7 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos, } /* Short read but not EOF? Zero out the remainder. */ - if (ret >= 0 && ret < len && (off + ret < i_size)) { + if (ret < len && (off + ret < i_size)) { int zlen = min(len - ret, i_size - off - ret); int zoff = page_off + ret; @@ -1197,13 +1204,11 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos, ret += zlen; } - idx = 0; - if (ret <= 0) - left = 0; - else if (off + ret > i_size) - left = i_size - off; + if (off + ret > i_size) + left = (i_size > off) ? i_size - off : 0; else left = ret; + while (left > 0) { size_t plen, copied; @@ -1222,12 +1227,6 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos, ceph_osdc_put_request(req); - if (ret < 0) { - if (ret == -EBLOCKLISTED) - fsc->blocklisted = true; - break; - } - if (off >= i_size || !more) break; } -- 2.34.1
