[PATCH v4 2/8] ext4: add wrapper functions for buffer layer
From: Zheng Liu <hidden>
Date: 2012-01-23 16:50:22
Also in:
linux-fsdevel
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
Wrapper functions are defined to account the result of different IO type. CC: Jens Axboe <axboe@kernel.dk> CC: Steven Whitehouse <redacted> CC: Aditya Kali <redacted> Signed-off-by: Wang Shaoyan <redacted> Signed-off-by: Zheng Liu <redacted> --- fs/ext4/ext4.h | 21 +++++++++++++++ fs/ext4/super.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 99 insertions(+), 0 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 7ec0596..688891e 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h@@ -1968,6 +1968,27 @@ static inline void ext4_ios_read(struct super_block *sb, int type, __ext4_io_stat(sb, READ, type, count); } +extern void ext4_submit_bh_read_nowait(int rw, struct buffer_head *bh, + struct super_block *sb, int type, + unsigned long count); +extern int ext4_submit_bh_read(int rw, struct buffer_head *bh, + struct super_block *sb, int type, + unsigned long count); +extern void ext4_submit_bh_write_nowait(int rw, struct buffer_head *bh, + struct super_block *sb, int type, + unsigned long count); +extern struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block, + int type, unsigned long count); +extern void ext4_sb_breadahead(struct super_block *sb, + sector_t block, int type); + +static inline int ext4_bh_submit_read(struct buffer_head *bh, + struct super_block *sb, + int type, unsigned long count) +{ + return ext4_submit_bh_read(READ, bh, sb, type, count); +} + extern void *ext4_kvmalloc(size_t size, gfp_t flags); extern void *ext4_kvzalloc(size_t size, gfp_t flags); extern void ext4_kvfree(void *ptr);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f3a5cab..305ece7 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c@@ -4999,6 +4999,84 @@ count: __ext4_io_stat(sb, WRITE, type, count); } +void ext4_submit_bh_read_nowait(int rw, struct buffer_head *bh, + struct super_block *sb, int type, + unsigned long count) +{ + BUG_ON(rw & WRITE); + BUG_ON(!buffer_locked(bh)); + + /* IO type accouting */ + ext4_ios_read(sb, type, count); + + get_bh(bh); + bh->b_end_io = end_buffer_read_sync; + submit_bh(rw, bh); +} + +int ext4_submit_bh_read(int rw, struct buffer_head *bh, struct super_block *sb, + int type, unsigned long count) +{ + BUG_ON(rw & WRITE); + BUG_ON(!buffer_locked(bh)); + + if (buffer_uptodate(bh)) { + unlock_buffer(bh); + return 0; + } + + ext4_submit_bh_read_nowait(rw, bh, sb, type, count); + wait_on_buffer(bh); + if (buffer_uptodate(bh)) + return 0; + return -EIO; +} + +void ext4_submit_bh_write_nowait(int rw, struct buffer_head *bh, + struct super_block *sb, int type, + unsigned long count) +{ + BUG_ON(!(rw & WRITE)); + BUG_ON(!buffer_locked(bh)); + + /* IO type accouting */ + ext4_ios_write(sb, NULL, NULL, type, count); + + get_bh(bh); + bh->b_end_io = end_buffer_write_sync; + submit_bh(rw, bh); +} + +struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block, + int type, unsigned long count) +{ + struct buffer_head *bh = __getblk(sb->s_bdev, block, sb->s_blocksize); + + if (likely(bh) && !buffer_uptodate(bh)) { + lock_buffer(bh); + if (ext4_submit_bh_read(READ, bh, sb, type, count)) { + brelse(bh); + bh = NULL; + } + } + return bh; +} + +void ext4_sb_breadahead(struct super_block *sb, sector_t block, int type) +{ + struct buffer_head *bh = __getblk(sb->s_bdev, block, sb->s_blocksize); + if (likely(bh)) { + if (trylock_buffer(bh)) { + if (buffer_uptodate(bh)) + ext4_submit_bh_read_nowait(READ, bh, sb, + type, 1); + else + unlock_buffer(bh); + } + brelse(bh); + } +} + static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) {
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1.7.4.1