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-rw-r--r--fs/ext3/balloc.c266
1 files changed, 266 insertions, 0 deletions
diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c
index b3db2264942..045995c8ce5 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;
+}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-24 16:30:42 +0000