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authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2010-07-18 05:42:23 +0400
committerRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2010-07-23 05:02:15 +0400
commit26dfdd8e29f28c08aa67861b3c83d0f3f7d30cee (patch)
tree3cc14a71010b454f6524006e973147837f040a39 /fs/nilfs2/btnode.c
parentf8e6cc013b896d75d6ce4ec9e168014af1257fd8 (diff)
downloadlinux-26dfdd8e29f28c08aa67861b3c83d0f3f7d30cee.tar.xz
nilfs2: add read ahead mode to nilfs_btnode_submit_block
This adds mode argument to nilfs_btnode_submit_block() function and allows it to issue a read-ahead request. An optional submit_ptr argument is also added to store the actual block address for which bio is sent. submit_ptr is used for a series of read-ahead requests, and helps to decide if each requested block is continous to the previous one on disk. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Diffstat (limited to 'fs/nilfs2/btnode.c')
-rw-r--r--fs/nilfs2/btnode.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c
index 0a6834bb278e..f78ab1044d1d 100644
--- a/fs/nilfs2/btnode.c
+++ b/fs/nilfs2/btnode.c
@@ -96,7 +96,8 @@ nilfs_btnode_create_block(struct address_space *btnc, __u64 blocknr)
}
int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr,
- sector_t pblocknr, struct buffer_head **pbh)
+ sector_t pblocknr, int mode,
+ struct buffer_head **pbh, sector_t *submit_ptr)
{
struct buffer_head *bh;
struct inode *inode = NILFS_BTNC_I(btnc);
@@ -127,7 +128,16 @@ int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr,
}
}
}
- lock_buffer(bh);
+
+ if (mode == READA) {
+ if (pblocknr != *submit_ptr + 1 || !trylock_buffer(bh)) {
+ err = -EBUSY; /* internal code */
+ brelse(bh);
+ goto out_locked;
+ }
+ } else { /* mode == READ */
+ lock_buffer(bh);
+ }
if (buffer_uptodate(bh)) {
unlock_buffer(bh);
err = -EEXIST; /* internal code */
@@ -138,8 +148,9 @@ int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr,
bh->b_blocknr = pblocknr; /* set block address for read */
bh->b_end_io = end_buffer_read_sync;
get_bh(bh);
- submit_bh(READ, bh);
+ submit_bh(mode, bh);
bh->b_blocknr = blocknr; /* set back to the given block address */
+ *submit_ptr = pblocknr;
err = 0;
found:
*pbh = bh;