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-rw-r--r--fs/ocfs2/buffer_head_io.c77
1 files changed, 59 insertions, 18 deletions
diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c
index 9f8250df99f1..f9b84f7a3e4b 100644
--- a/fs/ocfs2/buffer_head_io.c
+++ b/fs/ocfs2/buffer_head_io.c
@@ -99,25 +99,34 @@ out:
return ret;
}
+/* Caller must provide a bhs[] with all NULL or non-NULL entries, so it
+ * will be easier to handle read failure.
+ */
int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
unsigned int nr, struct buffer_head *bhs[])
{
int status = 0;
unsigned int i;
struct buffer_head *bh;
+ int new_bh = 0;
trace_ocfs2_read_blocks_sync((unsigned long long)block, nr);
if (!nr)
goto bail;
+ /* Don't put buffer head and re-assign it to NULL if it is allocated
+ * outside since the caller can't be aware of this alternation!
+ */
+ new_bh = (bhs[0] == NULL);
+
for (i = 0 ; i < nr ; i++) {
if (bhs[i] == NULL) {
bhs[i] = sb_getblk(osb->sb, block++);
if (bhs[i] == NULL) {
status = -ENOMEM;
mlog_errno(status);
- goto bail;
+ break;
}
}
bh = bhs[i];
@@ -157,9 +166,26 @@ int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
submit_bh(REQ_OP_READ, 0, bh);
}
+read_failure:
for (i = nr; i > 0; i--) {
bh = bhs[i - 1];
+ if (unlikely(status)) {
+ if (new_bh && bh) {
+ /* If middle bh fails, let previous bh
+ * finish its read and then put it to
+ * aovoid bh leak
+ */
+ if (!buffer_jbd(bh))
+ wait_on_buffer(bh);
+ put_bh(bh);
+ bhs[i - 1] = NULL;
+ } else if (bh && buffer_uptodate(bh)) {
+ clear_buffer_uptodate(bh);
+ }
+ continue;
+ }
+
/* No need to wait on the buffer if it's managed by JBD. */
if (!buffer_jbd(bh))
wait_on_buffer(bh);
@@ -169,8 +195,7 @@ int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
* so we can safely record this and loop back
* to cleanup the other buffers. */
status = -EIO;
- put_bh(bh);
- bhs[i - 1] = NULL;
+ goto read_failure;
}
}
@@ -178,6 +203,9 @@ bail:
return status;
}
+/* Caller must provide a bhs[] with all NULL or non-NULL entries, so it
+ * will be easier to handle read failure.
+ */
int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
struct buffer_head *bhs[], int flags,
int (*validate)(struct super_block *sb,
@@ -187,6 +215,7 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
int i, ignore_cache = 0;
struct buffer_head *bh;
struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
+ int new_bh = 0;
trace_ocfs2_read_blocks_begin(ci, (unsigned long long)block, nr, flags);
@@ -212,6 +241,11 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
goto bail;
}
+ /* Don't put buffer head and re-assign it to NULL if it is allocated
+ * outside since the caller can't be aware of this alternation!
+ */
+ new_bh = (bhs[0] == NULL);
+
ocfs2_metadata_cache_io_lock(ci);
for (i = 0 ; i < nr ; i++) {
if (bhs[i] == NULL) {
@@ -220,7 +254,8 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
ocfs2_metadata_cache_io_unlock(ci);
status = -ENOMEM;
mlog_errno(status);
- goto bail;
+ /* Don't forget to put previous bh! */
+ break;
}
}
bh = bhs[i];
@@ -314,16 +349,27 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
}
}
- status = 0;
-
+read_failure:
for (i = (nr - 1); i >= 0; i--) {
bh = bhs[i];
if (!(flags & OCFS2_BH_READAHEAD)) {
- if (status) {
- /* Clear the rest of the buffers on error */
- put_bh(bh);
- bhs[i] = NULL;
+ if (unlikely(status)) {
+ /* Clear the buffers on error including those
+ * ever succeeded in reading
+ */
+ if (new_bh && bh) {
+ /* If middle bh fails, let previous bh
+ * finish its read and then put it to
+ * aovoid bh leak
+ */
+ if (!buffer_jbd(bh))
+ wait_on_buffer(bh);
+ put_bh(bh);
+ bhs[i] = NULL;
+ } else if (bh && buffer_uptodate(bh)) {
+ clear_buffer_uptodate(bh);
+ }
continue;
}
/* We know this can't have changed as we hold the
@@ -341,9 +387,7 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
* uptodate. */
status = -EIO;
clear_buffer_needs_validate(bh);
- put_bh(bh);
- bhs[i] = NULL;
- continue;
+ goto read_failure;
}
if (buffer_needs_validate(bh)) {
@@ -353,11 +397,8 @@ int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
BUG_ON(buffer_jbd(bh));
clear_buffer_needs_validate(bh);
status = validate(sb, bh);
- if (status) {
- put_bh(bh);
- bhs[i] = NULL;
- continue;
- }
+ if (status)
+ goto read_failure;
}
}