diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 215b7068f548..3dd9b9e2f967 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4814,7 +4814,7 @@ ext4_mb_release_group_pa(struct ext4_buddy *e4b, */ static noinline_for_stack int ext4_mb_discard_group_preallocations(struct super_block *sb, - ext4_group_t group, int needed) + ext4_group_t group, int *busy) { struct ext4_group_info *grp = ext4_get_group_info(sb, group); struct buffer_head *bitmap_bh = NULL; @@ -4822,8 +4822,7 @@ ext4_mb_discard_group_preallocations(struct super_block *sb, struct list_head list; struct ext4_buddy e4b; int err; - int busy = 0; - int free, free_total = 0; + int free = 0; mb_debug(sb, "discard preallocation for group %u\n", group); if (list_empty(&grp->bb_prealloc_list)) @@ -4846,19 +4845,14 @@ ext4_mb_discard_group_preallocations(struct super_block *sb, goto out_dbg; } - if (needed == 0) - needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1; - INIT_LIST_HEAD(&list); -repeat: - free = 0; ext4_lock_group(sb, group); list_for_each_entry_safe(pa, tmp, &grp->bb_prealloc_list, pa_group_list) { spin_lock(&pa->pa_lock); if (atomic_read(&pa->pa_count)) { spin_unlock(&pa->pa_lock); - busy = 1; + *busy = 1; continue; } if (pa->pa_deleted) { @@ -4898,22 +4892,13 @@ repeat: call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); } - free_total += free; - - /* if we still need more blocks and some PAs were used, try again */ - if (free_total < needed && busy) { - ext4_unlock_group(sb, group); - cond_resched(); - busy = 0; - goto repeat; - } ext4_unlock_group(sb, group); ext4_mb_unload_buddy(&e4b); put_bh(bitmap_bh); out_dbg: mb_debug(sb, "discarded (%d) blocks preallocated for group %u bb_free (%d)\n", - free_total, group, grp->bb_free); - return free_total; + free, group, grp->bb_free); + return free; } /* @@ -5455,13 +5440,24 @@ static int ext4_mb_discard_preallocations(struct super_block *sb, int needed) { ext4_group_t i, ngroups = ext4_get_groups_count(sb); int ret; - int freed = 0; + int freed = 0, busy = 0; + int retry = 0; trace_ext4_mb_discard_preallocations(sb, needed); + + if (needed == 0) + needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1; + repeat: for (i = 0; i < ngroups && needed > 0; i++) { - ret = ext4_mb_discard_group_preallocations(sb, i, needed); + ret = ext4_mb_discard_group_preallocations(sb, i, &busy); freed += ret; needed -= ret; + cond_resched(); + } + + if (needed > 0 && busy && ++retry < 3) { + busy = 0; + goto repeat; } return freed;