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| author | OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> | 2006-01-08 01:02:11 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-08 20:13:46 -0800 |
| commit | e5174baaea7585760f02eef23b225847d209a8db (patch) | |
| tree | 34198b0f205a91670104abc800ec560e14296db3 /fs/fat/cache.c | |
| parent | 7c709d00d614d0f2b6a80895b2a1aedbe04e8478 (diff) | |
| download | lwn-e5174baaea7585760f02eef23b225847d209a8db.tar.gz lwn-e5174baaea7585760f02eef23b225847d209a8db.zip | |
[PATCH] fat: support ->direct_IO()
This patch add to support of ->direct_IO() for mostly read.
The user of this seems to want to use for streaming read. So, current direct
I/O has limitation, it can only overwrite. (For write operation, mainly we
need to handle the hole etc..)
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/fat/cache.c')
| -rw-r--r-- | fs/fat/cache.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/fs/fat/cache.c b/fs/fat/cache.c index 77c24fcf712a..1acc941245fb 100644 --- a/fs/fat/cache.c +++ b/fs/fat/cache.c @@ -295,7 +295,8 @@ static int fat_bmap_cluster(struct inode *inode, int cluster) return dclus; } -int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys) +int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, + unsigned long *mapped_blocks) { struct super_block *sb = inode->i_sb; struct msdos_sb_info *sbi = MSDOS_SB(sb); @@ -303,9 +304,12 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys) int cluster, offset; *phys = 0; + *mapped_blocks = 0; if ((sbi->fat_bits != 32) && (inode->i_ino == MSDOS_ROOT_INO)) { - if (sector < (sbi->dir_entries >> sbi->dir_per_block_bits)) + if (sector < (sbi->dir_entries >> sbi->dir_per_block_bits)) { *phys = sector + sbi->dir_start; + *mapped_blocks = 1; + } return 0; } last_block = (MSDOS_I(inode)->mmu_private + (sb->s_blocksize - 1)) @@ -318,7 +322,11 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys) cluster = fat_bmap_cluster(inode, cluster); if (cluster < 0) return cluster; - else if (cluster) + else if (cluster) { *phys = fat_clus_to_blknr(sbi, cluster) + offset; + *mapped_blocks = sbi->sec_per_clus - offset; + if (*mapped_blocks > last_block - sector) + *mapped_blocks = last_block - sector; + } return 0; } |