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author | Jan Kara <jack@suse.cz> | 2013-06-04 13:21:11 -0400 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2013-06-04 13:21:11 -0400 |
commit | 6b523df4fb5ae281ddbc817f40504b33e6226554 (patch) | |
tree | f129ccf336689296ff21e34ed86712b25d437a65 /fs/ext4/extents.c | |
parent | 3613d22807a2616e9346800bacd88aa8bbbefcd7 (diff) | |
download | kernel_goldelico_gta04-6b523df4fb5ae281ddbc817f40504b33e6226554.zip kernel_goldelico_gta04-6b523df4fb5ae281ddbc817f40504b33e6226554.tar.gz kernel_goldelico_gta04-6b523df4fb5ae281ddbc817f40504b33e6226554.tar.bz2 |
ext4: use transaction reservation for extent conversion in ext4_end_io
Later we would like to clear PageWriteback bit only after extent
conversion from unwritten to written extents is performed. However it
is not possible to start a transaction after PageWriteback is set
because that violates lock ordering (and is easy to deadlock). So we
have to reserve a transaction before locking pages and sending them
for IO and later we use the transaction for extent conversion from
ext4_end_io().
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/extents.c')
-rw-r--r-- | fs/ext4/extents.c | 40 |
1 files changed, 29 insertions, 11 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 94283d0..208f664 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4566,10 +4566,9 @@ retry: * function, to convert the fallocated extents after IO is completed. * Returns 0 on success. */ -int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset, - ssize_t len) +int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode, + loff_t offset, ssize_t len) { - handle_t *handle; unsigned int max_blocks; int ret = 0; int ret2 = 0; @@ -4584,16 +4583,32 @@ int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset, max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) - map.m_lblk); /* - * credits to insert 1 extent into extent tree + * This is somewhat ugly but the idea is clear: When transaction is + * reserved, everything goes into it. Otherwise we rather start several + * smaller transactions for conversion of each extent separately. */ - credits = ext4_chunk_trans_blocks(inode, max_blocks); + if (handle) { + handle = ext4_journal_start_reserved(handle, + EXT4_HT_EXT_CONVERT); + if (IS_ERR(handle)) + return PTR_ERR(handle); + credits = 0; + } else { + /* + * credits to insert 1 extent into extent tree + */ + credits = ext4_chunk_trans_blocks(inode, max_blocks); + } while (ret >= 0 && ret < max_blocks) { map.m_lblk += ret; map.m_len = (max_blocks -= ret); - handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, credits); - if (IS_ERR(handle)) { - ret = PTR_ERR(handle); - break; + if (credits) { + handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, + credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + break; + } } ret = ext4_map_blocks(handle, inode, &map, EXT4_GET_BLOCKS_IO_CONVERT_EXT); @@ -4604,10 +4619,13 @@ int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset, inode->i_ino, map.m_lblk, map.m_len, ret); ext4_mark_inode_dirty(handle, inode); - ret2 = ext4_journal_stop(handle); - if (ret <= 0 || ret2 ) + if (credits) + ret2 = ext4_journal_stop(handle); + if (ret <= 0 || ret2) break; } + if (!credits) + ret2 = ext4_journal_stop(handle); return ret > 0 ? ret2 : ret; } |