ext4: online defrag-- Allocate new contiguous blocks with mballoc
From: Akira Fujita <a-fujita@xxxxxxxxxxxxx>
Search contiguous free blocks with mutil-block allocation
and allocate them for the temporary inode.
Signed-off-by: Akira Fujita <a-fujita@xxxxxxxxxxxxx>
Signed-off-by: Takashi Sato <t-sato@xxxxxxxxxxxxx>
---
fs/ext4/defrag.c | 286 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/ext4/ext4.h | 5 +
fs/ext4/ext4_extents.h | 3 +
fs/ext4/extents.c | 6 +-
4 files changed, 297 insertions(+), 3 deletions(-)
diff --git a/fs/ext4/defrag.c b/fs/ext4/defrag.c
index a03da84..09b2c56 100644
--- a/fs/ext4/defrag.c
+++ b/fs/ext4/defrag.c
@@ -6,6 +6,75 @@
#include "group.h"
/**
+ * ext4_defrag_next_extent - Search for the next extent and set it to "extent"
+ *
+ * @inode: inode of the the original file
+ * @path: this will obtain data for the next extent
+ * @extent: pointer to the next extent we have just gotten
+ *
+ * This function returns 0 or 1(last entry) if succeeded, otherwise
+ * returns -EIO.
+ */
+static int
+ext4_defrag_next_extent(struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_extent **extent)
+{
+ int ppos;
+ int leaf_ppos = path->p_depth;
+
+ ppos = leaf_ppos;
+ if (EXT_LAST_EXTENT(path[ppos].p_hdr) > path[ppos].p_ext) {
+ /* leaf block */
+ *extent = ++path[ppos].p_ext;
+ return 0;
+ }
+
+ while (--ppos >= 0) {
+ if (EXT_LAST_INDEX(path[ppos].p_hdr) >
+ path[ppos].p_idx) {
+ int cur_ppos = ppos;
+
+ /* index block */
+ path[ppos].p_idx++;
+ path[ppos].p_block =
+ idx_pblock(path[ppos].p_idx);
+ if (path[ppos+1].p_bh)
+ brelse(path[ppos+1].p_bh);
+ path[ppos+1].p_bh =
+ sb_bread(inode->i_sb, path[ppos].p_block);
+ if (!path[ppos+1].p_bh)
+ return -EIO;
+ path[ppos+1].p_hdr =
+ ext_block_hdr(path[ppos+1].p_bh);
+
+ /* Halfway index block */
+ while (++cur_ppos < leaf_ppos) {
+ path[cur_ppos].p_idx =
+ EXT_FIRST_INDEX(path[cur_ppos].p_hdr);
+ path[cur_ppos].p_block =
+ idx_pblock(path[cur_ppos].p_idx);
+ if (path[cur_ppos+1].p_bh)
+ brelse(path[cur_ppos+1].p_bh);
+ path[cur_ppos+1].p_bh = sb_bread(inode->i_sb,
+ path[cur_ppos].p_block);
+ if (!path[cur_ppos+1].p_bh)
+ return -EIO;
+ path[cur_ppos+1].p_hdr =
+ ext_block_hdr(path[cur_ppos+1].p_bh);
+ }
+
+ /* leaf block */
+ path[leaf_ppos].p_ext = *extent =
+ EXT_FIRST_EXTENT(path[leaf_ppos].p_hdr);
+ return 0;
+ }
+ }
+ /* We found the last extent */
+ return 1;
+}
+
+/**
* ext4_defrag_merge_across_blocks - Merge extents across leaf block
*
* @handle journal handle
@@ -618,6 +687,148 @@ out:
}
/**
+ * ext4_defrag_alloc_blocks - Allocate contiguous blocks to temporary inode
+ *
+ * @dest_inode temporary inode for multiple block allocation
+ * @org_inode original inode
+ * @iblock file related offset
+ * @total_blocks contiguous blocks count
+ *
+ * If succeed, fuction returns count of extent we got,
+ * otherwise returns err.
+ */
+static int ext4_defrag_alloc_blocks(struct inode *dest_inode,
+ struct inode *org_inode, ext4_lblk_t iblock,
+ ext4_fsblk_t total_blocks)
+{
+ handle_t *handle = NULL;
+ struct ext4_ext_path *dest_path = NULL;
+ struct ext4_ext_path *org_path = NULL;
+ struct ext4_extent newex;
+ struct ext4_allocation_request ar;
+ struct buffer_head *bh = NULL;
+ struct super_block *org_sb = org_inode->i_sb;
+ ext4_fsblk_t newblock = 0;
+ ext4_fsblk_t rest = total_blocks;
+ ext4_fsblk_t alloc_total = 0;
+ unsigned long org_len;
+ ext4_group_t dest_grp_no;
+ ext4_grpblk_t dest_blk_off;
+ int metadata = 1;
+ int count = 0;
+ int credits = 0;
+ int err = 0;
+ int err2 = 0;
+ int len_cnt = 0;
+
+ ar.len = total_blocks;
+ org_len = ar.len;
+
+ /* Find first extent */
+ dest_path = ext4_ext_find_extent(dest_inode, iblock, dest_path);
+ if (IS_ERR(dest_path)) {
+ err = PTR_ERR(dest_path);
+ dest_path = NULL;
+ goto out2;
+ }
+
+ ar.inode = dest_inode;
+ ar.flags = EXT4_MB_HINT_DATA | EXT4_MB_HINT_RESERVED
+ | EXT4_MB_HINT_NOPREALLOC;
+
+ ar.goal = ext4_ext_find_goal(dest_inode, dest_path, iblock);
+
+ ar.logical = iblock;
+ ar.lleft = 0;
+ ar.pleft = 0;
+ ar.lright = 0;
+ ar.pright = 0;
+
+ handle = ext4_journal_start(dest_inode, credits);
+ if (IS_ERR(handle)) {
+ err = PTR_ERR(handle);
+ goto out2;
+ }
+
+ while (alloc_total != total_blocks) {
+ credits = ext4_ext_calc_credits_for_insert(dest_inode,
+ dest_path);
+ handle = ext4_ext_journal_restart(handle,
+ credits + EXT4_TRANS_META_BLOCKS);
+
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ newblock = ext4_mb_new_blocks(handle, &ar, &err);
+
+ if (err) {
+ /* Failed to get the contiguous blocks */
+ goto out;
+ } else {
+ /*
+ * Dirty buffer_head causes the overwriting
+ * if ext4_mb_new_blocks() allocates the block
+ * which used to be the metadata block.
+ * We should call unmap_underlying_metadata()
+ * to clear the dirty flag.
+ */
+ for (len_cnt = 0; len_cnt < ar.len; len_cnt++) {
+ bh = sb_find_get_block(org_sb,
+ newblock + len_cnt);
+ unmap_underlying_metadata(org_sb->s_bdev,
+ newblock + len_cnt);
+ }
+
+ alloc_total += ar.len;
+ ext4_get_group_no_and_offset(dest_inode->i_sb,
+ newblock, &dest_grp_no, &dest_blk_off);
+
+ newex.ee_block = cpu_to_le32(alloc_total - ar.len);
+ ext4_ext_store_pblock(&newex, newblock);
+ newex.ee_len = cpu_to_le16(ar.len);
+
+ ar.goal = newblock + ar.len;
+ rest = rest - ar.len;
+ ar.len = rest;
+
+ err = ext4_ext_insert_extent(handle, dest_inode,
+ dest_path, &newex);
+ if (!err) {
+ count++;
+ } else {
+ ext4_free_blocks(handle, org_inode,
+ newblock, ar.len, metadata);
+ goto out;
+ }
+ }
+ }
+
+out:
+ if (err) {
+ /* Faild case: We have to remove halfway blocks */
+ err2 = ext4_ext_remove_space(dest_inode, 0);
+ if (err2)
+ printk(KERN_ERR "ext4 defrag: "
+ "Failed to remove temporary inode blocks\n");
+ }
+out2:
+ if (dest_path) {
+ ext4_ext_drop_refs(dest_path);
+ kfree(dest_path);
+ }
+ if (org_path) {
+ ext4_ext_drop_refs(org_path);
+ kfree(org_path);
+ }
+
+ ext4_journal_stop(handle);
+
+ /* Return extents count or err value */
+ return (!err ? count : err);
+
+}
+
+/**
* ext4_defrag_partial - Defrag a file per page
*
* @tmp_inode: the inode which has blocks to swap with original
@@ -736,3 +947,78 @@ out:
return (ret < 0 ? ret : 0);
}
+
+/**
+ * ext4_defrag_new_extent_tree - Check extents improves or not
+ *
+ * @inode: inode of the original file
+ * @tmp_inode: inode of the temporary file
+ * @path: the structure holding some info about
+ * original extent tree
+ * @tar_start: starting offset to allocate in blocks
+ * @tar_blocks: the number of blocks to allocate
+ * @iblock: file related offset
+ *
+ * This function returns the value as below:
+ * 0(succeeded)
+ * 1(not improved)
+ * negative value(error)
+ */
+static int
+ext4_defrag_new_extent_tree(struct inode *inode, struct inode *tmp_inode,
+ struct ext4_ext_path *path, ext4_lblk_t tar_start,
+ ext4_lblk_t tar_blocks, ext4_lblk_t iblock)
+{
+ struct ext4_extent *ext = NULL;
+ struct ext4_extent_header *eh = NULL;
+ ext4_lblk_t tar_end = tar_start + tar_blocks - 1;
+ int sum_org = 0, sum_tmp = 0;
+ int ret = 0, depth;
+ int last_extent = 0;
+
+ eh = ext_inode_hdr(tmp_inode);
+ eh->eh_depth = 0;
+
+ /* Allocate contiguous blocks */
+ sum_tmp = ext4_defrag_alloc_blocks(tmp_inode, inode, iblock,
+ tar_blocks);
+ if (sum_tmp < 0) {
+ ret = sum_tmp;
+ goto out;
+ }
+
+ depth = ext_depth(inode);
+ ext = path[depth].p_ext;
+ /* Compare the number of the original extents with new one. */
+ while (1) {
+ if (!last_extent)
+ ++sum_org;
+
+ if (tar_end <= le32_to_cpu(ext->ee_block) +
+ le16_to_cpu(ext->ee_len) - 1 ||
+ last_extent) {
+
+ if (sum_org == sum_tmp) {
+ /* Not improved */
+ ret = ext4_ext_remove_space(tmp_inode, 0);
+ if (!ret)
+ ret = 1;
+ } else if (sum_org < sum_tmp) {
+ /* Fragment increased */
+ ret = ext4_ext_remove_space(tmp_inode, 0);
+ if (!ret)
+ ret = -ENOSPC;
+ printk(KERN_ERR "ext4 defrag: "
+ "Insufficient free blocks\n");
+ }
+ break;
+ }
+ last_extent = ext4_defrag_next_extent(tmp_inode, path, &ext);
+ if (last_extent < 0) {
+ ret = last_extent;
+ break;
+ }
+ }
+out:
+ return ret;
+}
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 92162f9..8dc174f 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -315,6 +315,8 @@ struct ext4_new_group_data {
#define EXT4_IOC32_GETVERSION_OLD FS_IOC32_GETVERSION
#define EXT4_IOC32_SETVERSION_OLD FS_IOC32_SETVERSION
+#define EXT4_TRANS_META_BLOCKS 4 /* bitmap + group desc + sb + inode */
+
/*
* Mount options
@@ -1110,6 +1112,8 @@ extern void ext4_inode_bitmap_set(struct super_block *sb,
struct ext4_group_desc *bg, ext4_fsblk_t blk);
extern void ext4_inode_table_set(struct super_block *sb,
struct ext4_group_desc *bg, ext4_fsblk_t blk);
+/* extents.c */
+extern handle_t *ext4_ext_journal_restart(handle_t *handle, int needed);
static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
{
@@ -1227,6 +1231,7 @@ extern int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode,
sector_t block, unsigned long max_blocks,
struct buffer_head *bh, int create,
int extend_disksize);
+extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start);
#endif /* __KERNEL__ */
#endif /* _EXT4_H */
diff --git a/fs/ext4/ext4_extents.h b/fs/ext4/ext4_extents.h
index 9868c02..734c1c7 100644
--- a/fs/ext4/ext4_extents.h
+++ b/fs/ext4/ext4_extents.h
@@ -230,5 +230,8 @@ extern int ext4_ext_search_right(struct inode *, struct ext4_ext_path *,
extern void ext4_ext_drop_refs(struct ext4_ext_path *);
extern ext4_fsblk_t ext_pblock(struct ext4_extent *ex);
extern void ext4_ext_drop_refs(struct ext4_ext_path *path);
+extern ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t block);
#endif /* _EXT4_EXTENTS */
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 1293b47..e60e51b 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -92,7 +92,7 @@ static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb)
ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
}
-static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed)
+handle_t *ext4_ext_journal_restart(handle_t *handle, int needed)
{
int err;
@@ -142,7 +142,7 @@ static int ext4_ext_dirty(handle_t *handle, struct inode *inode,
return err;
}
-static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
+ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
struct ext4_ext_path *path,
ext4_lblk_t block)
{
@@ -1956,7 +1956,7 @@ ext4_ext_more_to_rm(struct ext4_ext_path *path)
return 1;
}
-static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
+int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
{
struct super_block *sb = inode->i_sb;
int depth = ext_depth(inode);
--
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