diff options
author | Kirill Korotaev <dev@sw.ru> | 2005-06-23 00:09:54 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-23 09:45:27 -0700 |
commit | 618f06362ae3f60f95d7b0e666de25ee6ae35679 (patch) | |
tree | 4415b4e590913e16535704168ea74c6af5a93c48 /fs/quota.c | |
parent | 4fea2838aa00b9e59efde974dcdb455608192811 (diff) | |
download | linux-stable-618f06362ae3f60f95d7b0e666de25ee6ae35679.tar.gz linux-stable-618f06362ae3f60f95d7b0e666de25ee6ae35679.tar.bz2 linux-stable-618f06362ae3f60f95d7b0e666de25ee6ae35679.zip |
[PATCH] O(1) sb list traversing on syncs
This patch removes O(n^2) super block loops in sync_inodes(),
sync_filesystems() etc. in favour of using __put_super_and_need_restart()
which I introduced earlier. We faced a noticably long freezes on sb
syncing when there are thousands of super blocks in the system.
Signed-Off-By: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/quota.c')
-rw-r--r-- | fs/quota.c | 60 |
1 files changed, 24 insertions, 36 deletions
diff --git a/fs/quota.c b/fs/quota.c index 3f0333a51a23..f5d1cff55196 100644 --- a/fs/quota.c +++ b/fs/quota.c @@ -149,36 +149,6 @@ static int check_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t return error; } -static struct super_block *get_super_to_sync(int type) -{ - struct list_head *head; - int cnt, dirty; - -restart: - spin_lock(&sb_lock); - list_for_each(head, &super_blocks) { - struct super_block *sb = list_entry(head, struct super_block, s_list); - - /* This test just improves performance so it needn't be reliable... */ - for (cnt = 0, dirty = 0; cnt < MAXQUOTAS; cnt++) - if ((type == cnt || type == -1) && sb_has_quota_enabled(sb, cnt) - && info_any_dirty(&sb_dqopt(sb)->info[cnt])) - dirty = 1; - if (!dirty) - continue; - sb->s_count++; - spin_unlock(&sb_lock); - down_read(&sb->s_umount); - if (!sb->s_root) { - drop_super(sb); - goto restart; - } - return sb; - } - spin_unlock(&sb_lock); - return NULL; -} - static void quota_sync_sb(struct super_block *sb, int type) { int cnt; @@ -219,17 +189,35 @@ static void quota_sync_sb(struct super_block *sb, int type) void sync_dquots(struct super_block *sb, int type) { + int cnt, dirty; + if (sb) { if (sb->s_qcop->quota_sync) quota_sync_sb(sb, type); + return; } - else { - while ((sb = get_super_to_sync(type)) != NULL) { - if (sb->s_qcop->quota_sync) - quota_sync_sb(sb, type); - drop_super(sb); - } + + spin_lock(&sb_lock); +restart: + list_for_each_entry(sb, &super_blocks, s_list) { + /* This test just improves performance so it needn't be reliable... */ + for (cnt = 0, dirty = 0; cnt < MAXQUOTAS; cnt++) + if ((type == cnt || type == -1) && sb_has_quota_enabled(sb, cnt) + && info_any_dirty(&sb_dqopt(sb)->info[cnt])) + dirty = 1; + if (!dirty) + continue; + sb->s_count++; + spin_unlock(&sb_lock); + down_read(&sb->s_umount); + if (sb->s_root && sb->s_qcop->quota_sync) + quota_sync_sb(sb, type); + up_read(&sb->s_umount); + spin_lock(&sb_lock); + if (__put_super_and_need_restart(sb)) + goto restart; } + spin_unlock(&sb_lock); } /* Copy parameters and call proper function */ |