This inserts readahead in the recovery code. The readahead request is issued per segment while searching the latest super root block.
This will shorten mount time after unclean unmount. A measurement shows the recovery time was reduced by more than 60 percent: e.g. real 0m11.586s -> 0m3.918s (x 2.96) Signed-off-by: Ryusuke Konishi <[email protected]> --- fs/nilfs2/recovery.c | 26 +++++++++++++++++++------- 1 files changed, 19 insertions(+), 7 deletions(-) diff --git a/fs/nilfs2/recovery.c b/fs/nilfs2/recovery.c index bcd386d..6d5412e 100644 --- a/fs/nilfs2/recovery.c +++ b/fs/nilfs2/recovery.c @@ -798,6 +798,7 @@ int nilfs_search_super_root(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, struct nilfs_segsum_info ssi; sector_t pseg_start, pseg_end, sr_pseg_start = 0; sector_t seg_start, seg_end; /* range of full segment (block number) */ + sector_t b, end; u64 seg_seq; __u64 segnum, nextnum = 0; __u64 cno; @@ -813,6 +814,11 @@ int nilfs_search_super_root(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, /* Calculate range of segment */ nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); + /* Read ahead segment */ + b = seg_start; + while (b <= seg_end) + sb_breadahead(sbi->s_super, b++); + for (;;) { /* Load segment summary */ ret = load_segment_summary(sbi, pseg_start, seg_seq, &ssi, 1); @@ -835,14 +841,20 @@ int nilfs_search_super_root(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, ri->ri_nextnum = nextnum; empty_seg = 0; + if (!NILFS_SEG_HAS_SR(&ssi) && !scan_newer) { + /* This will never happen because a superblock + (last_segment) always points to a pseg + having a super root. */ + ret = NILFS_SEG_FAIL_CONSISTENCY; + goto failed; + } + + if (pseg_start == seg_start) { + nilfs_get_segment_range(nilfs, nextnum, &b, &end); + while (b <= end) + sb_breadahead(sbi->s_super, b++); + } if (!NILFS_SEG_HAS_SR(&ssi)) { - if (!scan_newer) { - /* This will never happen because a superblock - (last_segment) always points to a pseg - having a super root. */ - ret = NILFS_SEG_FAIL_CONSISTENCY; - goto failed; - } if (!ri->ri_lsegs_start && NILFS_SEG_LOGBGN(&ssi)) { ri->ri_lsegs_start = pseg_start; ri->ri_lsegs_start_seq = seg_seq; -- 1.6.3.4 _______________________________________________ users mailing list [email protected] https://www.nilfs.org/mailman/listinfo/users
