diff options
Diffstat (limited to 'fs/ext4/extents.c')
| -rw-r--r-- | fs/ext4/extents.c | 188 |
1 files changed, 28 insertions, 160 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 26481e543312..b52ac813ca20 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3819,83 +3819,6 @@ out: return ext4_mark_inode_dirty(handle, inode); } -/** - * Determines how many complete clusters (out of those specified by the 'map') - * are under delalloc and were reserved quota for. - * This function is called when we are writing out the blocks that were - * originally written with their allocation delayed, but then the space was - * allocated using fallocate() before the delayed allocation could be resolved. - * The cases to look for are: - * ('=' indicated delayed allocated blocks - * '-' indicates non-delayed allocated blocks) - * (a) partial clusters towards beginning and/or end outside of allocated range - * are not delalloc'ed. - * Ex: - * |----c---=|====c====|====c====|===-c----| - * |++++++ allocated ++++++| - * ==> 4 complete clusters in above example - * - * (b) partial cluster (outside of allocated range) towards either end is - * marked for delayed allocation. In this case, we will exclude that - * cluster. - * Ex: - * |----====c========|========c========| - * |++++++ allocated ++++++| - * ==> 1 complete clusters in above example - * - * Ex: - * |================c================| - * |++++++ allocated ++++++| - * ==> 0 complete clusters in above example - * - * The ext4_da_update_reserve_space will be called only if we - * determine here that there were some "entire" clusters that span - * this 'allocated' range. - * In the non-bigalloc case, this function will just end up returning num_blks - * without ever calling ext4_find_delalloc_range. - */ -static unsigned int -get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start, - unsigned int num_blks) -{ - struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); - ext4_lblk_t alloc_cluster_start, alloc_cluster_end; - ext4_lblk_t lblk_from, lblk_to, c_offset; - unsigned int allocated_clusters = 0; - - alloc_cluster_start = EXT4_B2C(sbi, lblk_start); - alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1); - - /* max possible clusters for this allocation */ - allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1; - - trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks); - - /* Check towards left side */ - c_offset = EXT4_LBLK_COFF(sbi, lblk_start); - if (c_offset) { - lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start); - lblk_to = lblk_from + c_offset - 1; - - if (ext4_es_scan_range(inode, &ext4_es_is_delayed, lblk_from, - lblk_to)) - allocated_clusters--; - } - - /* Now check towards right. */ - c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks); - if (allocated_clusters && c_offset) { - lblk_from = lblk_start + num_blks; - lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1; - - if (ext4_es_scan_range(inode, &ext4_es_is_delayed, lblk_from, - lblk_to)) - allocated_clusters--; - } - - return allocated_clusters; -} - static int convert_initialized_extent(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, @@ -4077,23 +4000,6 @@ out: } map->m_len = allocated; - /* - * If we have done fallocate with the offset that is already - * delayed allocated, we would have block reservation - * and quota reservation done in the delayed write path. - * But fallocate would have already updated quota and block - * count for this offset. So cancel these reservation - */ - if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { - unsigned int reserved_clusters; - reserved_clusters = get_reserved_cluster_alloc(inode, - map->m_lblk, map->m_len); - if (reserved_clusters) - ext4_da_update_reserve_space(inode, - reserved_clusters, - 0); - } - map_out: map->m_flags |= EXT4_MAP_MAPPED; if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) { @@ -4482,77 +4388,39 @@ got_allocated_blocks: map->m_flags |= EXT4_MAP_NEW; /* - * Update reserved blocks/metadata blocks after successful - * block allocation which had been deferred till now. + * Reduce the reserved cluster count to reflect successful deferred + * allocation of delayed allocated clusters or direct allocation of + * clusters discovered to be delayed allocated. Once allocated, a + * cluster is not included in the reserved count. */ - if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { - unsigned int reserved_clusters; - /* - * Check how many clusters we had reserved this allocated range - */ - reserved_clusters = get_reserved_cluster_alloc(inode, - map->m_lblk, allocated); - if (!map_from_cluster) { - BUG_ON(allocated_clusters < reserved_clusters); - if (reserved_clusters < allocated_clusters) { - struct ext4_inode_info *ei = EXT4_I(inode); - int reservation = allocated_clusters - - reserved_clusters; - /* - * It seems we claimed few clusters outside of - * the range of this allocation. We should give - * it back to the reservation pool. This can - * happen in the following case: - * - * * Suppose s_cluster_ratio is 4 (i.e., each - * cluster has 4 blocks. Thus, the clusters - * are [0-3],[4-7],[8-11]... - * * First comes delayed allocation write for - * logical blocks 10 & 11. Since there were no - * previous delayed allocated blocks in the - * range [8-11], we would reserve 1 cluster - * for this write. - * * Next comes write for logical blocks 3 to 8. - * In this case, we will reserve 2 clusters - * (for [0-3] and [4-7]; and not for [8-11] as - * that range has a delayed allocated blocks. - * Thus total reserved clusters now becomes 3. - * * Now, during the delayed allocation writeout - * time, we will first write blocks [3-8] and - * allocate 3 clusters for writing these - * blocks. Also, we would claim all these - * three clusters above. - * * Now when we come here to writeout the - * blocks [10-11], we would expect to claim - * the reservation of 1 cluster we had made - * (and we would claim it since there are no - * more delayed allocated blocks in the range - * [8-11]. But our reserved cluster count had - * already gone to 0. - * - * Thus, at the step 4 above when we determine - * that there are still some unwritten delayed - * allocated blocks outside of our current - * block range, we should increment the - * reserved clusters count so that when the - * remaining blocks finally gets written, we - * could claim them. - */ - dquot_reserve_block(inode, - EXT4_C2B(sbi, reservation)); - spin_lock(&ei->i_block_reservation_lock); - ei->i_reserved_data_blocks += reservation; - spin_unlock(&ei->i_block_reservation_lock); - } + if (test_opt(inode->i_sb, DELALLOC) && !map_from_cluster) { + if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { /* - * We will claim quota for all newly allocated blocks. - * We're updating the reserved space *after* the - * correction above so we do not accidentally free - * all the metadata reservation because we might - * actually need it later on. + * When allocating delayed allocated clusters, simply + * reduce the reserved cluster count and claim quota */ ext4_da_update_reserve_space(inode, allocated_clusters, 1); + } else { + ext4_lblk_t lblk, len; + unsigned int n; + + /* + * When allocating non-delayed allocated clusters + * (from fallocate, filemap, DIO, or clusters + * allocated when delalloc has been disabled by + * ext4_nonda_switch), reduce the reserved cluster + * count by the number of allocated clusters that + * have previously been delayed allocated. Quota + * has been claimed by ext4_mb_new_blocks() above, + * so release the quota reservations made for any + * previously delayed allocated clusters. + */ + lblk = EXT4_LBLK_CMASK(sbi, map->m_lblk); + len = allocated_clusters << sbi->s_cluster_bits; + n = ext4_es_delayed_clu(inode, lblk, len); + if (n > 0) + ext4_da_update_reserve_space(inode, (int) n, 0); } } |