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author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-05-15 17:07:25 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-05-15 17:07:25 +0200 |
commit | 5d41343ac88eeddd25dc4ffb7050c9095c41a70d (patch) | |
tree | bb40dd5493d19276a806bbd35064c44922b11d93 | |
parent | Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiw... (diff) | |
parent | ext4: Fix race in ext4_inode_info.i_cached_extent (diff) | |
download | linux-5d41343ac88eeddd25dc4ffb7050c9095c41a70d.tar.xz linux-5d41343ac88eeddd25dc4ffb7050c9095c41a70d.zip |
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.c | 19 | ||||
-rw-r--r-- | fs/ext4/inode.c | 26 |
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; } |