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authorArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2009-01-27 16:12:31 +0200
committerArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2009-01-27 16:25:10 +0200
commit6f7ab6d458bbfc2f55d295fa3e6b9e69cdb1d517 (patch)
tree7d07f5ff88d205a652998c2fd281e7123ba9a112 /fs/ubifs/tnc.c
parent6ba87c9b920bea8c2703308d31eb7de925242c30 (diff)
downloadlinux-6f7ab6d458bbfc2f55d295fa3e6b9e69cdb1d517.tar.bz2
UBIFS: fix no_chk_data_crc
When data CRC checking is disabled, UBIFS returns incorrect return code from the 'try_read_node()' function (0 instead of 1, which means CRC error), which make the caller re-read the data node again, but using a different code patch, so the second read is fine. Thus, we read the same node twice. And the result of this is that UBIFS is slower with no_chk_data_crc option than it is with chk_data_crc option. This patches fixes the problem. Reported-by: Reuben Dowle <Reuben.Dowle@navico.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'fs/ubifs/tnc.c')
-rw-r--r--fs/ubifs/tnc.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index f7e36f545527..fa28a84c6a1b 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -443,6 +443,11 @@ static int tnc_read_node_nm(struct ubifs_info *c, struct ubifs_zbranch *zbr,
* This function performs that same function as ubifs_read_node except that
* it does not require that there is actually a node present and instead
* the return code indicates if a node was read.
+ *
+ * Note, this function does not check CRC of data nodes if @c->no_chk_data_crc
+ * is true (it is controlled by corresponding mount option). However, if
+ * @c->always_chk_crc is true, @c->no_chk_data_crc is ignored and CRC is always
+ * checked.
*/
static int try_read_node(const struct ubifs_info *c, void *buf, int type,
int len, int lnum, int offs)
@@ -470,9 +475,8 @@ static int try_read_node(const struct ubifs_info *c, void *buf, int type,
if (node_len != len)
return 0;
- if (type == UBIFS_DATA_NODE && !c->always_chk_crc)
- if (c->no_chk_data_crc)
- return 0;
+ if (type == UBIFS_DATA_NODE && !c->always_chk_crc && c->no_chk_data_crc)
+ return 1;
crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8);
node_crc = le32_to_cpu(ch->crc);
@@ -1506,7 +1510,7 @@ out:
*
* Note, if the bulk-read buffer length (@bu->buf_len) is known, this function
* makes sure bulk-read nodes fit the buffer. Otherwise, this function prepares
- * maxumum possible amount of nodes for bulk-read.
+ * maximum possible amount of nodes for bulk-read.
*/
int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu)
{