diff options
Diffstat (limited to 'fs/ext3')
| -rw-r--r-- | fs/ext3/balloc.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c index b3db22649426..045995c8ce5a 100644 --- a/fs/ext3/balloc.c +++ b/fs/ext3/balloc.c @@ -20,6 +20,7 @@ #include <linux/ext3_jbd.h> #include <linux/quotaops.h> #include <linux/buffer_head.h> +#include <linux/blkdev.h> /* * balloc.c contains the blocks allocation and deallocation routines @@ -39,6 +40,21 @@ #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) +/* + * Calculate the block group number and offset, given a block number + */ +static void ext3_get_group_no_and_offset(struct super_block *sb, + ext3_fsblk_t blocknr, unsigned long *blockgrpp, ext3_grpblk_t *offsetp) +{ + struct ext3_super_block *es = EXT3_SB(sb)->s_es; + + blocknr = blocknr - le32_to_cpu(es->s_first_data_block); + if (offsetp) + *offsetp = blocknr % EXT3_BLOCKS_PER_GROUP(sb); + if (blockgrpp) + *blockgrpp = blocknr / EXT3_BLOCKS_PER_GROUP(sb); +} + /** * ext3_get_group_desc() -- load group descriptor from disk * @sb: super block @@ -1885,3 +1901,253 @@ unsigned long ext3_bg_num_gdb(struct super_block *sb, int group) return ext3_bg_num_gdb_meta(sb,group); } + +/** + * ext3_trim_all_free -- function to trim all free space in alloc. group + * @sb: super block for file system + * @group: allocation group to trim + * @start: first group block to examine + * @max: last group block to examine + * @gdp: allocation group description structure + * @minblocks: minimum extent block count + * + * ext3_trim_all_free walks through group's block bitmap searching for free + * blocks. When the free block is found, it tries to allocate this block and + * consequent free block to get the biggest free extent possible, until it + * reaches any used block. Then issue a TRIM command on this extent and free + * the extent in the block bitmap. This is done until whole group is scanned. + */ +ext3_grpblk_t ext3_trim_all_free(struct super_block *sb, unsigned int group, + ext3_grpblk_t start, ext3_grpblk_t max, + ext3_grpblk_t minblocks) +{ + handle_t *handle; + ext3_grpblk_t next, free_blocks, bit, freed, count = 0; + ext3_fsblk_t discard_block; + struct ext3_sb_info *sbi; + struct buffer_head *gdp_bh, *bitmap_bh = NULL; + struct ext3_group_desc *gdp; + int err = 0, ret = 0; + + /* + * We will update one block bitmap, and one group descriptor + */ + handle = ext3_journal_start_sb(sb, 2); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + bitmap_bh = read_block_bitmap(sb, group); + if (!bitmap_bh) { + err = -EIO; + goto err_out; + } + + BUFFER_TRACE(bitmap_bh, "getting undo access"); + err = ext3_journal_get_undo_access(handle, bitmap_bh); + if (err) + goto err_out; + + gdp = ext3_get_group_desc(sb, group, &gdp_bh); + if (!gdp) { + err = -EIO; + goto err_out; + } + + BUFFER_TRACE(gdp_bh, "get_write_access"); + err = ext3_journal_get_write_access(handle, gdp_bh); + if (err) + goto err_out; + + free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); + sbi = EXT3_SB(sb); + + /* Walk through the whole group */ + while (start < max) { + start = bitmap_search_next_usable_block(start, bitmap_bh, max); + if (start < 0) + break; + next = start; + + /* + * Allocate contiguous free extents by setting bits in the + * block bitmap + */ + while (next < max + && claim_block(sb_bgl_lock(sbi, group), + next, bitmap_bh)) { + next++; + } + + /* We did not claim any blocks */ + if (next == start) + continue; + + discard_block = (ext3_fsblk_t)start + + ext3_group_first_block_no(sb, group); + + /* Update counters */ + spin_lock(sb_bgl_lock(sbi, group)); + le16_add_cpu(&gdp->bg_free_blocks_count, start - next); + spin_unlock(sb_bgl_lock(sbi, group)); + percpu_counter_sub(&sbi->s_freeblocks_counter, next - start); + + /* Do not issue a TRIM on extents smaller than minblocks */ + if ((next - start) < minblocks) + goto free_extent; + + /* Send the TRIM command down to the device */ + err = sb_issue_discard(sb, discard_block, next - start, + GFP_NOFS, 0); + count += (next - start); +free_extent: + freed = 0; + + /* + * Clear bits in the bitmap + */ + for (bit = start; bit < next; bit++) { + BUFFER_TRACE(bitmap_bh, "clear bit"); + if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, group), + bit, bitmap_bh->b_data)) { + ext3_error(sb, __func__, + "bit already cleared for block "E3FSBLK, + (unsigned long)bit); + BUFFER_TRACE(bitmap_bh, "bit already cleared"); + } else { + freed++; + } + } + + /* Update couters */ + spin_lock(sb_bgl_lock(sbi, group)); + le16_add_cpu(&gdp->bg_free_blocks_count, freed); + spin_unlock(sb_bgl_lock(sbi, group)); + percpu_counter_add(&sbi->s_freeblocks_counter, freed); + + start = next; + if (err < 0) { + if (err != -EOPNOTSUPP) + ext3_warning(sb, __func__, "Discard command " + "returned error %d\n", err); + break; + } + + if (fatal_signal_pending(current)) { + err = -ERESTARTSYS; + break; + } + + cond_resched(); + + /* No more suitable extents */ + if ((free_blocks - count) < minblocks) + break; + } + + /* We dirtied the bitmap block */ + BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); + ret = ext3_journal_dirty_metadata(handle, bitmap_bh); + if (!err) + err = ret; + + /* And the group descriptor block */ + BUFFER_TRACE(gdp_bh, "dirtied group descriptor block"); + ret = ext3_journal_dirty_metadata(handle, gdp_bh); + if (!err) + err = ret; + + ext3_debug("trimmed %d blocks in the group %d\n", + count, group); + +err_out: + if (err) + count = err; + ext3_journal_stop(handle); + brelse(bitmap_bh); + + return count; +} + +/** + * ext3_trim_fs() -- trim ioctl handle function + * @sb: superblock for filesystem + * @start: First Byte to trim + * @len: number of Bytes to trim from start + * @minlen: minimum extent length in Bytes + * + * ext3_trim_fs goes through all allocation groups containing Bytes from + * start to start+len. For each such a group ext3_trim_all_free function + * is invoked to trim all free space. + */ +int ext3_trim_fs(struct super_block *sb, struct fstrim_range *range) +{ + ext3_grpblk_t last_block, first_block, free_blocks; + unsigned long first_group, last_group; + unsigned long group, ngroups; + struct ext3_group_desc *gdp; + struct ext3_super_block *es = EXT3_SB(sb)->s_es; + uint64_t start, len, minlen, trimmed; + ext3_fsblk_t max_blks = le32_to_cpu(es->s_blocks_count); + int ret = 0; + + start = range->start >> sb->s_blocksize_bits; + len = range->len >> sb->s_blocksize_bits; + minlen = range->minlen >> sb->s_blocksize_bits; + trimmed = 0; + + if (unlikely(minlen > EXT3_BLOCKS_PER_GROUP(sb))) + return -EINVAL; + if (start >= max_blks) + goto out; + if (start < le32_to_cpu(es->s_first_data_block)) { + len -= le32_to_cpu(es->s_first_data_block) - start; + start = le32_to_cpu(es->s_first_data_block); + } + if (start + len > max_blks) + len = max_blks - start; + + ngroups = EXT3_SB(sb)->s_groups_count; + smp_rmb(); + + /* Determine first and last group to examine based on start and len */ + ext3_get_group_no_and_offset(sb, (ext3_fsblk_t) start, + &first_group, &first_block); + ext3_get_group_no_and_offset(sb, (ext3_fsblk_t) (start + len), + &last_group, &last_block); + last_group = (last_group > ngroups - 1) ? ngroups - 1 : last_group; + last_block = EXT3_BLOCKS_PER_GROUP(sb); + + if (first_group > last_group) + return -EINVAL; + + for (group = first_group; group <= last_group; group++) { + gdp = ext3_get_group_desc(sb, group, NULL); + if (!gdp) + break; + + free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); + if (free_blocks < minlen) + continue; + + if (len >= EXT3_BLOCKS_PER_GROUP(sb)) + len -= (EXT3_BLOCKS_PER_GROUP(sb) - first_block); + else + last_block = first_block + len; + + ret = ext3_trim_all_free(sb, group, first_block, + last_block, minlen); + if (ret < 0) + break; + + trimmed += ret; + first_block = 0; + } + + if (ret >= 0) + ret = 0; + +out: + range->len = trimmed * sb->s_blocksize; + + return ret; +} |