free_space = btrfs_super_total_bytes(disk_super);
/*
- * we allow the metadata to grow to a max of either 5gb or 5% of the
+ * we allow the metadata to grow to a max of either 10gb or 5% of the
* space in the volume.
*/
- min_metadata = min((u64)5 * 1024 * 1024 * 1024,
+ min_metadata = min((u64)10 * 1024 * 1024 * 1024,
div64_u64(free_space * 5, 100));
if (info->total_bytes >= min_metadata) {
spin_unlock(&info->lock);
}
enum btrfs_loop_type {
- LOOP_CACHED_ONLY = 0,
+ LOOP_FIND_IDEAL = 0,
LOOP_CACHING_NOWAIT = 1,
LOOP_CACHING_WAIT = 2,
LOOP_ALLOC_CHUNK = 3,
struct btrfs_block_group_cache *block_group = NULL;
int empty_cluster = 2 * 1024 * 1024;
int allowed_chunk_alloc = 0;
+ int done_chunk_alloc = 0;
struct btrfs_space_info *space_info;
int last_ptr_loop = 0;
int loop = 0;
bool found_uncached_bg = false;
bool failed_cluster_refill = false;
bool failed_alloc = false;
+ u64 ideal_cache_percent = 0;
+ u64 ideal_cache_offset = 0;
WARN_ON(num_bytes < root->sectorsize);
btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
empty_cluster = 0;
if (search_start == hint_byte) {
+ideal_cache:
block_group = btrfs_lookup_block_group(root->fs_info,
search_start);
/*
* we don't want to use the block group if it doesn't match our
* allocation bits, or if its not cached.
+ *
+ * However if we are re-searching with an ideal block group
+ * picked out then we don't care that the block group is cached.
*/
if (block_group && block_group_bits(block_group, data) &&
- block_group_cache_done(block_group)) {
+ (block_group->cached != BTRFS_CACHE_NO ||
+ search_start == ideal_cache_offset)) {
down_read(&space_info->groups_sem);
if (list_empty(&block_group->list) ||
block_group->ro) {
*/
btrfs_put_block_group(block_group);
up_read(&space_info->groups_sem);
- } else
+ } else {
goto have_block_group;
+ }
} else if (block_group) {
btrfs_put_block_group(block_group);
}
}
-
search:
down_read(&space_info->groups_sem);
list_for_each_entry(block_group, &space_info->block_groups, list) {
have_block_group:
if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
+ u64 free_percent;
+
+ free_percent = btrfs_block_group_used(&block_group->item);
+ free_percent *= 100;
+ free_percent = div64_u64(free_percent,
+ block_group->key.offset);
+ free_percent = 100 - free_percent;
+ if (free_percent > ideal_cache_percent &&
+ likely(!block_group->ro)) {
+ ideal_cache_offset = block_group->key.objectid;
+ ideal_cache_percent = free_percent;
+ }
+
/*
- * we want to start caching kthreads, but not too many
- * right off the bat so we don't overwhelm the system,
- * so only start them if there are less than 2 and we're
- * in the initial allocation phase.
+ * We only want to start kthread caching if we are at
+ * the point where we will wait for caching to make
+ * progress, or if our ideal search is over and we've
+ * found somebody to start caching.
*/
if (loop > LOOP_CACHING_NOWAIT ||
- atomic_read(&space_info->caching_threads) < 2) {
+ (loop > LOOP_FIND_IDEAL &&
+ atomic_read(&space_info->caching_threads) < 2)) {
ret = cache_block_group(block_group);
BUG_ON(ret);
}
- }
-
- cached = block_group_cache_done(block_group);
- if (unlikely(!cached)) {
found_uncached_bg = true;
- /* if we only want cached bgs, loop */
- if (loop == LOOP_CACHED_ONLY)
+ /*
+ * If loop is set for cached only, try the next block
+ * group.
+ */
+ if (loop == LOOP_FIND_IDEAL)
goto loop;
}
+ cached = block_group_cache_done(block_group);
+ if (unlikely(!cached))
+ found_uncached_bg = true;
+
if (unlikely(block_group->ro))
goto loop;
}
up_read(&space_info->groups_sem);
- /* LOOP_CACHED_ONLY, only search fully cached block groups
- * LOOP_CACHING_NOWAIT, search partially cached block groups, but
- * dont wait foR them to finish caching
+ /* LOOP_FIND_IDEAL, only search caching/cached bg's, and don't wait for
+ * for them to make caching progress. Also
+ * determine the best possible bg to cache
+ * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
+ * caching kthreads as we move along
* LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
* LOOP_ALLOC_CHUNK, force a chunk allocation and try again
* LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE &&
(found_uncached_bg || empty_size || empty_cluster ||
allowed_chunk_alloc)) {
- if (found_uncached_bg) {
+ if (loop == LOOP_FIND_IDEAL && found_uncached_bg) {
found_uncached_bg = false;
- if (loop < LOOP_CACHING_WAIT) {
- loop++;
+ loop++;
+ if (!ideal_cache_percent &&
+ atomic_read(&space_info->caching_threads))
goto search;
- }
+
+ /*
+ * 1 of the following 2 things have happened so far
+ *
+ * 1) We found an ideal block group for caching that
+ * is mostly full and will cache quickly, so we might
+ * as well wait for it.
+ *
+ * 2) We searched for cached only and we didn't find
+ * anything, and we didn't start any caching kthreads
+ * either, so chances are we will loop through and
+ * start a couple caching kthreads, and then come back
+ * around and just wait for them. This will be slower
+ * because we will have 2 caching kthreads reading at
+ * the same time when we could have just started one
+ * and waited for it to get far enough to give us an
+ * allocation, so go ahead and go to the wait caching
+ * loop.
+ */
+ loop = LOOP_CACHING_WAIT;
+ search_start = ideal_cache_offset;
+ ideal_cache_percent = 0;
+ goto ideal_cache;
+ } else if (loop == LOOP_FIND_IDEAL) {
+ /*
+ * Didn't find a uncached bg, wait on anything we find
+ * next.
+ */
+ loop = LOOP_CACHING_WAIT;
+ goto search;
+ }
+
+ if (loop < LOOP_CACHING_WAIT) {
+ loop++;
+ goto search;
}
if (loop == LOOP_ALLOC_CHUNK) {
ret = do_chunk_alloc(trans, root, num_bytes +
2 * 1024 * 1024, data, 1);
allowed_chunk_alloc = 0;
- } else {
+ done_chunk_alloc = 1;
+ } else if (!done_chunk_alloc) {
space_info->force_alloc = 1;
}
git.samba.org / sfrench / cifs-2.6.git / blobdiff