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authorLinus Torvalds <torvalds@linux-foundation.org>2009-05-15 08:07:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-05-15 08:07:25 -0700
commit5d41343ac88eeddd25dc4ffb7050c9095c41a70d (patch)
treebb40dd5493d19276a806bbd35064c44922b11d93
parentc244450dac6d83be1ceadf29a65a5b49c34ceed8 (diff)
parent2ec0ae3acec47f628179ee95fe2c4da01b5e9fc4 (diff)
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: Fix race in ext4_inode_info.i_cached_extent ext4: Clear the unwritten buffer_head flag after the extent is initialized ext4: Use a fake block number for delayed new buffer_head ext4: Fix sub-block zeroing for writes into preallocated extents
-rw-r--r--fs/ext4/extents.c19
-rw-r--r--fs/ext4/inode.c26
2 files changed, 39 insertions, 6 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e40332158340..e3a55eb8b26a 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1841,11 +1841,13 @@ ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
{
struct ext4_ext_cache *cex;
BUG_ON(len == 0);
+ spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
cex = &EXT4_I(inode)->i_cached_extent;
cex->ec_type = type;
cex->ec_block = block;
cex->ec_len = len;
cex->ec_start = start;
+ spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
}
/*
@@ -1902,12 +1904,17 @@ ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
struct ext4_extent *ex)
{
struct ext4_ext_cache *cex;
+ int ret = EXT4_EXT_CACHE_NO;
+ /*
+ * We borrow i_block_reservation_lock to protect i_cached_extent
+ */
+ spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
cex = &EXT4_I(inode)->i_cached_extent;
/* has cache valid data? */
if (cex->ec_type == EXT4_EXT_CACHE_NO)
- return EXT4_EXT_CACHE_NO;
+ goto errout;
BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP &&
cex->ec_type != EXT4_EXT_CACHE_EXTENT);
@@ -1918,11 +1925,11 @@ ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
ext_debug("%u cached by %u:%u:%llu\n",
block,
cex->ec_block, cex->ec_len, cex->ec_start);
- return cex->ec_type;
+ ret = cex->ec_type;
}
-
- /* not in cache */
- return EXT4_EXT_CACHE_NO;
+errout:
+ spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+ return ret;
}
/*
@@ -2875,6 +2882,8 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
if (allocated > max_blocks)
allocated = max_blocks;
set_buffer_unwritten(bh_result);
+ bh_result->b_bdev = inode->i_sb->s_bdev;
+ bh_result->b_blocknr = newblock;
goto out2;
}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e91f978c7f12..2a9ffd528dd1 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1149,6 +1149,7 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
int retval;
clear_buffer_mapped(bh);
+ clear_buffer_unwritten(bh);
/*
* Try to see if we can get the block without requesting
@@ -1179,6 +1180,18 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
return retval;
/*
+ * When we call get_blocks without the create flag, the
+ * BH_Unwritten flag could have gotten set if the blocks
+ * requested were part of a uninitialized extent. We need to
+ * clear this flag now that we are committed to convert all or
+ * part of the uninitialized extent to be an initialized
+ * extent. This is because we need to avoid the combination
+ * of BH_Unwritten and BH_Mapped flags being simultaneously
+ * set on the buffer_head.
+ */
+ clear_buffer_unwritten(bh);
+
+ /*
* New blocks allocate and/or writing to uninitialized extent
* will possibly result in updating i_data, so we take
* the write lock of i_data_sem, and call get_blocks()
@@ -2297,6 +2310,10 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
int ret = 0;
+ sector_t invalid_block = ~((sector_t) 0xffff);
+
+ if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
+ invalid_block = ~0;
BUG_ON(create == 0);
BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
@@ -2318,11 +2335,18 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
/* not enough space to reserve */
return ret;
- map_bh(bh_result, inode->i_sb, 0);
+ map_bh(bh_result, inode->i_sb, invalid_block);
set_buffer_new(bh_result);
set_buffer_delay(bh_result);
} else if (ret > 0) {
bh_result->b_size = (ret << inode->i_blkbits);
+ /*
+ * With sub-block writes into unwritten extents
+ * we also need to mark the buffer as new so that
+ * the unwritten parts of the buffer gets correctly zeroed.
+ */
+ if (buffer_unwritten(bh_result))
+ set_buffer_new(bh_result);
ret = 0;
}