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| author | Zheng Liu <wenqing.lz@taobao.com> | 2012-07-09 16:29:29 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-07-09 16:29:29 -0400 |
| commit | 729f52c6be51013c9268e5fc85acbc1091286fdb (patch) | |
| tree | c3e8a6348ef23fcf15797b9f68905ec666ec43f8 /fs/ext4/ext4.h | |
| parent | fbe104942d3ff44f6802e8e4a3fbf267c1fb9ac4 (diff) | |
| download | blackbird-op-linux-729f52c6be51013c9268e5fc85acbc1091286fdb.tar.gz blackbird-op-linux-729f52c6be51013c9268e5fc85acbc1091286fdb.zip | |
ext4: add a new nolock flag in ext4_map_blocks
EXT4_GET_BLOCKS_NO_LOCK flag is added to indicate that we don't need
to acquire i_data_sem lock in ext4_map_blocks. Meanwhile, it changes
ext4_get_block() to not start a new journal because when we do a
overwrite dio, there is no any metadata that needs to be modified.
We define a new function called ext4_get_block_write_nolock, which is
used in dio overwrite nolock. In this function, it doesn't try to
acquire i_data_sem lock and doesn't start a new journal as it does a
lookup.
CC: Tao Ma <tm@tao.ma>
CC: Eric Sandeen <sandeen@redhat.com>
CC: Robin Dong <hao.bigrat@gmail.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ext4.h')
| -rw-r--r-- | fs/ext4/ext4.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 01434f25917d..4a49f8225d0b 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -571,6 +571,8 @@ enum { #define EXT4_GET_BLOCKS_NO_NORMALIZE 0x0040 /* Request will not result in inode size update (user for fallocate) */ #define EXT4_GET_BLOCKS_KEEP_SIZE 0x0080 + /* Do not take i_data_sem locking in ext4_map_blocks */ +#define EXT4_GET_BLOCKS_NO_LOCK 0x0100 /* * Flags used by ext4_free_blocks |
