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authorLi Dongyang <lidongyang@novell.com>2011-03-24 06:24:28 -0400
committerroot <Chris Mason chris.mason@oracle.com>2011-03-28 05:37:47 -0400
commitf7039b1d5c32241f87a513e33120db36bf30264d (patch)
treee911bc79c795fceb3e9a618d8f18571c2a776307 /fs/btrfs/free-space-cache.c
parent5378e60734f5b7bfe1b43dc191aaf6131c1befe7 (diff)
Btrfs: add btrfs_trim_fs() to handle FITRIM
We take an free extent out from allocator, trim it, then put it back, but before we trim the block group, we should make sure the block group is cached, so plus a little change to make cache_block_group() run without a transaction. Signed-off-by: Li Dongyang <lidongyang@novell.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/free-space-cache.c')
-rw-r--r--fs/btrfs/free-space-cache.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index f03ef97c3b21..0037427d8a9d 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2178,3 +2178,95 @@ void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
2178 cluster->block_group = NULL; 2178 cluster->block_group = NULL;
2179} 2179}
2180 2180
2181int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
2182 u64 *trimmed, u64 start, u64 end, u64 minlen)
2183{
2184 struct btrfs_free_space *entry = NULL;
2185 struct btrfs_fs_info *fs_info = block_group->fs_info;
2186 u64 bytes = 0;
2187 u64 actually_trimmed;
2188 int ret = 0;
2189
2190 *trimmed = 0;
2191
2192 while (start < end) {
2193 spin_lock(&block_group->tree_lock);
2194
2195 if (block_group->free_space < minlen) {
2196 spin_unlock(&block_group->tree_lock);
2197 break;
2198 }
2199
2200 entry = tree_search_offset(block_group, start, 0, 1);
2201 if (!entry)
2202 entry = tree_search_offset(block_group,
2203 offset_to_bitmap(block_group,
2204 start),
2205 1, 1);
2206
2207 if (!entry || entry->offset >= end) {
2208 spin_unlock(&block_group->tree_lock);
2209 break;
2210 }
2211
2212 if (entry->bitmap) {
2213 ret = search_bitmap(block_group, entry, &start, &bytes);
2214 if (!ret) {
2215 if (start >= end) {
2216 spin_unlock(&block_group->tree_lock);
2217 break;
2218 }
2219 bytes = min(bytes, end - start);
2220 bitmap_clear_bits(block_group, entry,
2221 start, bytes);
2222 if (entry->bytes == 0)
2223 free_bitmap(block_group, entry);
2224 } else {
2225 start = entry->offset + BITS_PER_BITMAP *
2226 block_group->sectorsize;
2227 spin_unlock(&block_group->tree_lock);
2228 ret = 0;
2229 continue;
2230 }
2231 } else {
2232 start = entry->offset;
2233 bytes = min(entry->bytes, end - start);
2234 unlink_free_space(block_group, entry);
2235 kfree(entry);
2236 }
2237
2238 spin_unlock(&block_group->tree_lock);
2239
2240 if (bytes >= minlen) {
2241 int update_ret;
2242 update_ret = btrfs_update_reserved_bytes(block_group,
2243 bytes, 1, 1);
2244
2245 ret = btrfs_error_discard_extent(fs_info->extent_root,
2246 start,
2247 bytes,
2248 &actually_trimmed);
2249
2250 btrfs_add_free_space(block_group,
2251 start, bytes);
2252 if (!update_ret)
2253 btrfs_update_reserved_bytes(block_group,
2254 bytes, 0, 1);
2255
2256 if (ret)
2257 break;
2258 *trimmed += actually_trimmed;
2259 }
2260 start += bytes;
2261 bytes = 0;
2262
2263 if (fatal_signal_pending(current)) {
2264 ret = -ERESTARTSYS;
2265 break;
2266 }
2267
2268 cond_resched();
2269 }
2270
2271 return ret;
2272}