diff options
| -rw-r--r-- | fs/nilfs2/cpfile.c | 58 |
1 files changed, 52 insertions, 6 deletions
diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c index 0d58075..b6596ca 100644 --- a/fs/nilfs2/cpfile.c +++ b/fs/nilfs2/cpfile.c @@ -53,6 +53,13 @@ nilfs_cpfile_get_offset(const struct inode *cpfile, __u64 cno) return do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile)); } +static __u64 nilfs_cpfile_first_checkpoint_in_block(const struct inode *cpfile, + unsigned long blkoff) +{ + return (__u64)nilfs_cpfile_checkpoints_per_block(cpfile) * blkoff + + 1 - NILFS_MDT(cpfile)->mi_first_entry_offset; +} + static unsigned long nilfs_cpfile_checkpoints_in_block(const struct inode *cpfile, __u64 curr, @@ -146,6 +153,44 @@ static inline int nilfs_cpfile_get_checkpoint_block(struct inode *cpfile, create, nilfs_cpfile_block_init, bhp); } +/** + * nilfs_cpfile_find_checkpoint_block - find and get a buffer on cpfile + * @cpfile: inode of cpfile + * @start_cno: start checkpoint number (inclusive) + * @end_cno: end checkpoint number (inclusive) + * @cnop: place to store the next checkpoint number + * @bhp: place to store a pointer to buffer_head struct + * + * Return Value: On success, it returns 0. On error, the following negative + * error code is returned. + * + * %-ENOMEM - Insufficient memory available. + * + * %-EIO - I/O error + * + * %-ENOENT - no block exists in the range. + */ +static int nilfs_cpfile_find_checkpoint_block(struct inode *cpfile, + __u64 start_cno, __u64 end_cno, + __u64 *cnop, + struct buffer_head **bhp) +{ + unsigned long start, end, blkoff; + int ret; + + if (unlikely(start_cno > end_cno)) + return -ENOENT; + + start = nilfs_cpfile_get_blkoff(cpfile, start_cno); + end = nilfs_cpfile_get_blkoff(cpfile, end_cno); + + ret = nilfs_mdt_find_block(cpfile, start, end, &blkoff, bhp); + if (!ret) + *cnop = (blkoff == start) ? start_cno : + nilfs_cpfile_first_checkpoint_in_block(cpfile, blkoff); + return ret; +} + static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile, __u64 cno) { @@ -403,14 +448,15 @@ static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop, return -ENOENT; /* checkpoint number 0 is invalid */ down_read(&NILFS_MDT(cpfile)->mi_sem); - for (n = 0; cno < cur_cno && n < nci; cno += ncps) { - ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno); - ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh); + for (n = 0; n < nci; cno += ncps) { + ret = nilfs_cpfile_find_checkpoint_block( + cpfile, cno, cur_cno - 1, &cno, &bh); if (ret < 0) { - if (ret != -ENOENT) - goto out; - continue; /* skip hole */ + if (likely(ret == -ENOENT)) + break; + goto out; } + ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno); kaddr = kmap_atomic(bh->b_page); cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); |
