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Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Browse Source 
* '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
This commit is contained in:
Linus Torvalds 2009-05-15 08:07:25 -07:00
commit 5d41343ac8
2 changed files with 39 additions and 6 deletions
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19
fs/ext4/extents.c
View File

@ -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;
}

26
fs/ext4/inode.c
View File

@ -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
@ -1178,6 +1179,18 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
if (retval > 0 && buffer_mapped(bh))
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
@ -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;
}