From 44183d4231a52a797beb477f962e1d361e31299d Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Mon, 9 May 2011 21:52:36 -0400 Subject: [PATCH] ext4: remove alloc_semp After taking care of all group init races, all that remains is to remove alloc_semp from ext4_allocation_context and ext4_buddy structs. Signed-off-by: Amir Goldstein Signed-off-by: "Theodore Ts'o" --- fs/ext4/mballoc.c | 31 +------------------------------ fs/ext4/mballoc.h | 6 ------ 2 files changed, 1 insertion(+), 36 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 1816eafb0a05..254f1f9fc4eb 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1130,24 +1130,8 @@ ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group, e4b->bd_group = group; e4b->bd_buddy_page = NULL; e4b->bd_bitmap_page = NULL; - e4b->alloc_semp = &grp->alloc_sem; - - /* Take the read lock on the group alloc - * sem. This would make sure a parallel - * ext4_mb_init_group happening on other - * groups mapped by the page is blocked - * till we are done with allocation - */ -repeat_load_buddy: - down_read(e4b->alloc_semp); if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { - /* we need to check for group need init flag - * with alloc_semp held so that we can be sure - * that new blocks didn't get added to the group - * when we are loading the buddy cache - */ - up_read(e4b->alloc_semp); /* * we need full data about the group * to make a good selection @@ -1155,7 +1139,6 @@ repeat_load_buddy: ret = ext4_mb_init_group(sb, group); if (ret) return ret; - goto repeat_load_buddy; } /* @@ -1247,9 +1230,6 @@ err: page_cache_release(e4b->bd_buddy_page); e4b->bd_buddy = NULL; e4b->bd_bitmap = NULL; - - /* Done with the buddy cache */ - up_read(e4b->alloc_semp); return ret; } @@ -1259,9 +1239,6 @@ static void ext4_mb_unload_buddy(struct ext4_buddy *e4b) page_cache_release(e4b->bd_bitmap_page); if (e4b->bd_buddy_page) page_cache_release(e4b->bd_buddy_page); - /* Done with the buddy cache */ - if (e4b->alloc_semp) - up_read(e4b->alloc_semp); } @@ -1574,9 +1551,6 @@ static void ext4_mb_use_best_found(struct ext4_allocation_context *ac, get_page(ac->ac_bitmap_page); ac->ac_buddy_page = e4b->bd_buddy_page; get_page(ac->ac_buddy_page); - /* on allocation we use ac to track the held semaphore */ - ac->alloc_semp = e4b->alloc_semp; - e4b->alloc_semp = NULL; /* store last allocated for subsequent stream allocation */ if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) { spin_lock(&sbi->s_md_lock); @@ -4188,15 +4162,12 @@ static int ext4_mb_release_context(struct ext4_allocation_context *ac) spin_unlock(&pa->pa_lock); } } - if (ac->alloc_semp) - up_read(ac->alloc_semp); if (pa) { /* * We want to add the pa to the right bucket. * Remove it from the list and while adding * make sure the list to which we are adding - * doesn't grow big. We need to release - * alloc_semp before calling ext4_mb_add_n_trim() + * doesn't grow big. */ if ((pa->pa_type == MB_GROUP_PA) && likely(pa->pa_free)) { spin_lock(pa->pa_obj_lock); diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h index 22bd4d7f289b..20b5e7bfebd1 100644 --- a/fs/ext4/mballoc.h +++ b/fs/ext4/mballoc.h @@ -193,11 +193,6 @@ struct ext4_allocation_context { __u8 ac_op; /* operation, for history only */ struct page *ac_bitmap_page; struct page *ac_buddy_page; - /* - * pointer to the held semaphore upon successful - * block allocation - */ - struct rw_semaphore *alloc_semp; struct ext4_prealloc_space *ac_pa; struct ext4_locality_group *ac_lg; }; @@ -215,7 +210,6 @@ struct ext4_buddy { struct super_block *bd_sb; __u16 bd_blkbits; ext4_group_t bd_group; - struct rw_semaphore *alloc_semp; }; #define EXT4_MB_BITMAP(e4b) ((e4b)->bd_bitmap) #define EXT4_MB_BUDDY(e4b) ((e4b)->bd_buddy)