We need to make sure adding new buffer_head to the
contiguous block extent doesn't result in nrblocks
greater than EXT4_MAX_TRANS_DATA. We only have
enought credit to insert EXT4_MAX_TRANS_DATA blocks.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
---
fs/ext4/inode.c | 38 +++++++++++++++++++++++++-------------
1 files changed, 25 insertions(+), 13 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index dcd1337..a10f8e5 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1909,27 +1909,39 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd)
static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
sector_t logical, struct buffer_head *bh)
{
- struct buffer_head *lbh = &mpd->lbh;
sector_t next;
+ size_t b_size = bh->b_size;
+ struct buffer_head *lbh = &mpd->lbh;
int nrblocks = lbh->b_size >> mpd->inode->i_blkbits;
/* check if thereserved journal credits might overflow */
- if (!(EXT4_I(mpd->inode)->i_flags & EXT4_EXTENTS_FL) &&
- (nrblocks >= EXT4_MAX_TRANS_DATA))
- /*
- * With noextent format we are limited by the journal
- * credit available. Total credit needed to insert
- * nrblocks contiguous blocks is dependent on the
- * nrblocks. So limit nrblocks.
- */
- goto flush_it;
-
+ if (!(EXT4_I(mpd->inode)->i_flags & EXT4_EXTENTS_FL)) {
+ if (nrblocks >= EXT4_MAX_TRANS_DATA) {
+ /*
+ * With noextent format we are limited by the journal
+ * credit available. Total credit needed to insert
+ * nrblocks contiguous blocks is dependent on the
+ * nrblocks. So limit nrblocks.
+ */
+ goto flush_it;
+ } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
+ EXT4_MAX_TRANS_DATA) {
+ /*
+ * Adding the new buffer_head would make it cross the
+ * allowed limit for which we have journal credit
+ * reserved. So limit the new bh->b_size
+ */
+ b_size = (EXT4_MAX_TRANS_DATA - nrblocks) <<
+ mpd->inode->i_blkbits;
+ /* we will do mpage_da_submit_io in the next loop */
+ }
+ }
/*
* First block in the extent
*/
if (lbh->b_size == 0) {
lbh->b_blocknr = logical;
- lbh->b_size = bh->b_size;
+ lbh->b_size = b_size;
lbh->b_state = bh->b_state & BH_FLAGS;
return;
}
@@ -1939,7 +1951,7 @@ static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
* Can we merge the block to our big extent?
*/
if (logical == next && (bh->b_state & BH_FLAGS) == lbh->b_state) {
- lbh->b_size += bh->b_size;
+ lbh->b_size += b_size;
return;
}
--
1.6.0.2.g2ebc0
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