diff options
Diffstat (limited to 'fs/ext3/balloc.c')
| -rw-r--r-- | fs/ext3/balloc.c | 135 |
1 files changed, 63 insertions, 72 deletions
diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c index ccd632f..e463dca 100644 --- a/fs/ext3/balloc.c +++ b/fs/ext3/balloc.c @@ -749,24 +749,24 @@ fail_access: * to find a free region that is of my size and has not * been reserved. * - * on succeed, it returns the reservation window to be appended to. - * failed, return NULL. */ -static struct ext3_reserve_window_node *find_next_reservable_window( +static int find_next_reservable_window( struct ext3_reserve_window_node *search_head, - unsigned long size, int *start_block, + struct ext3_reserve_window_node *my_rsv, + struct super_block * sb, int start_block, int last_block) { struct rb_node *next; struct ext3_reserve_window_node *rsv, *prev; int cur; + int size = my_rsv->rsv_goal_size; /* TODO: make the start of the reservation window byte-aligned */ /* cur = *start_block & ~7;*/ - cur = *start_block; + cur = start_block; rsv = search_head; if (!rsv) - return NULL; + return -1; while (1) { if (cur <= rsv->rsv_end) @@ -782,11 +782,11 @@ static struct ext3_reserve_window_node *find_next_reservable_window( * space with expected-size (or more)... */ if (cur > last_block) - return NULL; /* fail */ + return -1; /* fail */ prev = rsv; next = rb_next(&rsv->rsv_node); - rsv = list_entry(next, struct ext3_reserve_window_node, rsv_node); + rsv = list_entry(next,struct ext3_reserve_window_node,rsv_node); /* * Reached the last reservation, we can just append to the @@ -813,8 +813,25 @@ static struct ext3_reserve_window_node *find_next_reservable_window( * return the reservation window that we could append to. * succeed. */ - *start_block = cur; - return prev; + + if ((prev != my_rsv) && (!rsv_is_empty(&my_rsv->rsv_window))) + rsv_window_remove(sb, my_rsv); + + /* + * Let's book the whole avaliable window for now. We will check the + * disk bitmap later and then, if there are free blocks then we adjust + * the window size if it's larger than requested. + * Otherwise, we will remove this node from the tree next time + * call find_next_reservable_window. + */ + my_rsv->rsv_start = cur; + my_rsv->rsv_end = cur + size - 1; + my_rsv->rsv_alloc_hit = 0; + + if (prev != my_rsv) + ext3_rsv_window_add(sb, my_rsv); + + return 0; } /** @@ -852,6 +869,7 @@ static struct ext3_reserve_window_node *find_next_reservable_window( * @sb: the super block * @group: the group we are trying to allocate in * @bitmap_bh: the block group block bitmap + * */ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv, int goal, struct super_block *sb, @@ -860,10 +878,10 @@ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv, struct ext3_reserve_window_node *search_head; int group_first_block, group_end_block, start_block; int first_free_block; - int reservable_space_start; - struct ext3_reserve_window_node *prev_rsv; struct rb_root *fs_rsv_root = &EXT3_SB(sb)->s_rsv_window_root; unsigned long size; + int ret; + spinlock_t *rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock; group_first_block = le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) + group * EXT3_BLOCKS_PER_GROUP(sb); @@ -875,6 +893,7 @@ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv, start_block = goal + group_first_block; size = my_rsv->rsv_goal_size; + if (!rsv_is_empty(&my_rsv->rsv_window)) { /* * if the old reservation is cross group boundary @@ -908,6 +927,8 @@ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv, my_rsv->rsv_goal_size= size; } } + + spin_lock(rsv_lock); /* * shift the search start to the window near the goal block */ @@ -921,11 +942,16 @@ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv, * need to check the bitmap after we found a reservable window. */ retry: - prev_rsv = find_next_reservable_window(search_head, size, - &start_block, group_end_block); - if (prev_rsv == NULL) - goto failed; - reservable_space_start = start_block; + ret = find_next_reservable_window(search_head, my_rsv, sb, + start_block, group_end_block); + + if (ret == -1) { + if (!rsv_is_empty(&my_rsv->rsv_window)) + rsv_window_remove(sb, my_rsv); + spin_unlock(rsv_lock); + return -1; + } + /* * On success, find_next_reservable_window() returns the * reservation window where there is a reservable space after it. @@ -937,8 +963,9 @@ retry: * block. Search start from the start block of the reservable space * we just found. */ + spin_unlock(rsv_lock); first_free_block = bitmap_search_next_usable_block( - reservable_space_start - group_first_block, + my_rsv->rsv_start - group_first_block, bitmap_bh, group_end_block - group_first_block + 1); if (first_free_block < 0) { @@ -946,54 +973,29 @@ retry: * no free block left on the bitmap, no point * to reserve the space. return failed. */ - goto failed; + spin_lock(rsv_lock); + if (!rsv_is_empty(&my_rsv->rsv_window)) + rsv_window_remove(sb, my_rsv); + spin_unlock(rsv_lock); + return -1; /* failed */ } + start_block = first_free_block + group_first_block; /* * check if the first free block is within the - * free space we just found + * free space we just reserved */ - if ((start_block >= reservable_space_start) && - (start_block < reservable_space_start + size)) - goto found_rsv_window; + if (start_block >= my_rsv->rsv_start && start_block < my_rsv->rsv_end) + return 0; /* success */ /* * if the first free bit we found is out of the reservable space - * this means there is no free block on the reservable space - * we should continue search for next reservable space, + * continue search for next reservable space, * start from where the free block is, * we also shift the list head to where we stopped last time */ - search_head = prev_rsv; + search_head = my_rsv; + spin_lock(rsv_lock); goto retry; - -found_rsv_window: - /* - * great! the reservable space contains some free blocks. - * if the search returns that we should add the new - * window just next to where the old window, we don't - * need to remove the old window first then add it to the - * same place, just update the new start and new end. - */ - if (my_rsv != prev_rsv) { - if (!rsv_is_empty(&my_rsv->rsv_window)) - rsv_window_remove(sb, my_rsv); - } - my_rsv->rsv_start = reservable_space_start; - my_rsv->rsv_end = my_rsv->rsv_start + size - 1; - my_rsv->rsv_alloc_hit = 0; - if (my_rsv != prev_rsv) { - ext3_rsv_window_add(sb, my_rsv); - } - return 0; /* succeed */ -failed: - /* - * failed to find a new reservation window in the current - * group, remove the current(stale) reservation window - * if there is any - */ - if (!rsv_is_empty(&my_rsv->rsv_window)) - rsv_window_remove(sb, my_rsv); - return -1; /* failed */ } /* @@ -1023,7 +1025,6 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle, int goal, struct ext3_reserve_window_node * my_rsv, int *errp) { - spinlock_t *rsv_lock; unsigned long group_first_block; int ret = 0; int fatal; @@ -1052,7 +1053,6 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle, ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, goal, NULL); goto out; } - rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock; /* * goal is a group relative block number (if there is a goal) * 0 < goal < EXT3_BLOCKS_PER_GROUP(sb) @@ -1078,30 +1078,21 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle, * then we could go to allocate from the reservation window directly. */ while (1) { - struct ext3_reserve_window rsv_copy; - - rsv_copy._rsv_start = my_rsv->rsv_start; - rsv_copy._rsv_end = my_rsv->rsv_end; - - if (rsv_is_empty(&rsv_copy) || (ret < 0) || - !goal_in_my_reservation(&rsv_copy, goal, group, sb)) { - spin_lock(rsv_lock); + if (rsv_is_empty(&my_rsv->rsv_window) || (ret < 0) || + !goal_in_my_reservation(&my_rsv->rsv_window, goal, group, sb)) { ret = alloc_new_reservation(my_rsv, goal, sb, group, bitmap_bh); - rsv_copy._rsv_start = my_rsv->rsv_start; - rsv_copy._rsv_end = my_rsv->rsv_end; - spin_unlock(rsv_lock); if (ret < 0) break; /* failed */ - if (!goal_in_my_reservation(&rsv_copy, goal, group, sb)) + if (!goal_in_my_reservation(&my_rsv->rsv_window, goal, group, sb)) goal = -1; } - if ((rsv_copy._rsv_start >= group_first_block + EXT3_BLOCKS_PER_GROUP(sb)) - || (rsv_copy._rsv_end < group_first_block)) + if ((my_rsv->rsv_start >= group_first_block + EXT3_BLOCKS_PER_GROUP(sb)) + || (my_rsv->rsv_end < group_first_block)) BUG(); ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, goal, - &rsv_copy); + &my_rsv->rsv_window); if (ret >= 0) { my_rsv->rsv_alloc_hit++; break; /* succeed */ |
