diff options
Diffstat (limited to 'fs/ext4/mballoc.c')
| -rw-r--r-- | fs/ext4/mballoc.c | 70 |
1 files changed, 57 insertions, 13 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 4f2d3a9..aa499fe 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -658,6 +658,27 @@ static void ext4_mb_mark_free_simple(struct super_block *sb, } } +/* + * Cache the order of the largest free extent we have available in this block + * group. + */ +static void +mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp) +{ + int i; + int bits; + + grp->bb_largest_free_order = -1; /* uninit */ + + bits = sb->s_blocksize_bits + 1; + for (i = bits; i >= 0; i--) { + if (grp->bb_counters[i] > 0) { + grp->bb_largest_free_order = i; + break; + } + } +} + static noinline_for_stack void ext4_mb_generate_buddy(struct super_block *sb, void *buddy, void *bitmap, ext4_group_t group) @@ -700,6 +721,7 @@ void ext4_mb_generate_buddy(struct super_block *sb, */ grp->bb_free = free; } + mb_set_largest_free_order(sb, grp); clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state)); @@ -725,6 +747,9 @@ void ext4_mb_generate_buddy(struct super_block *sb, * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks. * So it can have information regarding groups_per_page which * is blocks_per_page/2 + * + * Locking note: This routine takes the block group lock of all groups + * for this page; do not hold this lock when calling this routine! */ static int ext4_mb_init_cache(struct page *page, char *incore) @@ -910,6 +935,11 @@ out: return err; } +/* + * Locking note: This routine calls ext4_mb_init_cache(), which takes the + * block group lock of all groups for this page; do not hold the BG lock when + * calling this routine! + */ static noinline_for_stack int ext4_mb_init_group(struct super_block *sb, ext4_group_t group) { @@ -1004,6 +1034,11 @@ err: return ret; } +/* + * Locking note: This routine calls ext4_mb_init_cache(), which takes the + * block group lock of all groups for this page; do not hold the BG lock when + * calling this routine! + */ static noinline_for_stack int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group, struct ext4_buddy *e4b) @@ -1299,6 +1334,7 @@ static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b, buddy = buddy2; } while (1); } + mb_set_largest_free_order(sb, e4b->bd_info); mb_check_buddy(e4b); } @@ -1427,6 +1463,7 @@ static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) e4b->bd_info->bb_counters[ord]++; e4b->bd_info->bb_counters[ord]++; } + mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info); mb_set_bits(EXT4_MB_BITMAP(e4b), ex->fe_start, len0); mb_check_buddy(e4b); @@ -1821,16 +1858,22 @@ void ext4_mb_scan_aligned(struct ext4_allocation_context *ac, } } +/* This is now called BEFORE we load the buddy bitmap. */ static int ext4_mb_good_group(struct ext4_allocation_context *ac, ext4_group_t group, int cr) { unsigned free, fragments; - unsigned i, bits; int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb)); struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); BUG_ON(cr < 0 || cr >= 4); - BUG_ON(EXT4_MB_GRP_NEED_INIT(grp)); + + /* We only do this if the grp has never been initialized */ + if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { + int ret = ext4_mb_init_group(ac->ac_sb, group); + if (ret) + return 0; + } free = grp->bb_free; fragments = grp->bb_fragments; @@ -1843,17 +1886,16 @@ static int ext4_mb_good_group(struct ext4_allocation_context *ac, case 0: BUG_ON(ac->ac_2order == 0); + if (grp->bb_largest_free_order < ac->ac_2order) + return 0; + /* Avoid using the first bg of a flexgroup for data files */ if ((ac->ac_flags & EXT4_MB_HINT_DATA) && (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) && ((group % flex_size) == 0)) return 0; - bits = ac->ac_sb->s_blocksize_bits + 1; - for (i = ac->ac_2order; i <= bits; i++) - if (grp->bb_counters[i] > 0) - return 1; - break; + return 1; case 1: if ((free / fragments) >= ac->ac_g_ex.fe_len) return 1; @@ -2024,14 +2066,11 @@ repeat: group = ac->ac_g_ex.fe_group; for (i = 0; i < ngroups; group++, i++) { - struct ext4_group_info *grp; - if (group == ngroups) group = 0; - /* quick check to skip empty groups */ - grp = ext4_get_group_info(sb, group); - if (grp->bb_free == 0) + /* This now checks without needing the buddy page */ + if (!ext4_mb_good_group(ac, group, cr)) continue; err = ext4_mb_load_buddy(sb, group, &e4b); @@ -2039,8 +2078,12 @@ repeat: goto out; ext4_lock_group(sb, group); + + /* + * We need to check again after locking the + * block group + */ if (!ext4_mb_good_group(ac, group, cr)) { - /* someone did allocation from this group */ ext4_unlock_group(sb, group); ext4_mb_unload_buddy(&e4b); continue; @@ -2253,6 +2296,7 @@ int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group, INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list); init_rwsem(&meta_group_info[i]->alloc_sem); meta_group_info[i]->bb_free_root = RB_ROOT; + meta_group_info[i]->bb_largest_free_order = -1; /* uninit */ #ifdef DOUBLE_CHECK { |