2006-11-09 11:10:26

by Takashi Sato

[permalink] [raw]
Subject: [RFC][PATCH 1/3] Allocate new contiguous blocks

Search contiguous free blocks with Alex's mutil-block allocation
and allocate them for the temporary inode.

This patch applies on top of Alex's patches.
"[RFC] extents,mballoc,delalloc for 2.6.16.8"
http://marc.theaimsgroup.com/?l=linux-ext4&m=114669168616780&w=2

Signed-off-by: Takashi Sato <[email protected]>
---
diff -upNr -X linux-2.6.16.8-alex-org/Documentation/dontdiff linux-2.6.16.8-alex-org/fs/ext3/extents.c linux-2.6.16.8-tmp1/fs/ext3/extents.c
--- linux-2.6.16.8-alex-org/fs/ext3/extents.c 2006-11-08 21:20:28.000000000 +0900
+++ linux-2.6.16.8-tmp1/fs/ext3/extents.c 2006-11-08 22:12:19.000000000 +0900
@@ -2341,11 +2341,418 @@ int ext3_ext_ioctl(struct inode *inode,
down(&EXT3_I(inode)->truncate_sem);
err = EXT_DEPTH(&tree);
up(&EXT3_I(inode)->truncate_sem);
+ } else if (cmd == EXT3_IOC_DEFRAG) {
+ struct ext3_ext_defrag_data defrag;
+
+ if (copy_from_user(&defrag,
+ (struct ext3_ext_defrag_data __user *)arg,
+ sizeof(defrag)))
+ return -EFAULT;
+
+ err = ext3_ext_defrag(filp, defrag.start_offset, defrag.defrag_size);
}

return err;
}

+/**
+ * ext3_ext_next_extent - search for next extent and set it to "extent"
+ * @inode: inode of the the original file
+ * @path: this will obtain data for next extent
+ * @extent: pointer to next extent we have just gotten
+ *
+ * This function returns 0 or 1(last_entry) if succeeded, otherwise
+ * returns -EIO
+ */
+static int
+ext3_ext_next_extent(struct inode *inode,
+ struct ext3_ext_path *path,
+ struct ext3_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 =
+ path[ppos].p_idx->ei_leaf;
+ 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 =
+ path[cur_ppos].p_idx->ei_leaf;
+ 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;
+ }
+ }
+ /* last_extent */
+ return 1;
+}
+
+/**
+ * ext3_ext_remove_index_blocks - remove leaf blocks and index blocks
+ * @handle handle
+ * @dest_tree extent tree of temporary inode
+ * @eh extent header
+ * @depth depth of extent tree
+ *
+ * This function returns 0 if succeed, otherwise returns error value
+ */
+static int ext3_ext_remove_index_blocks(handle_t *handle,
+ struct ext3_extents_tree *dest_tree,
+ struct ext3_extent_header *eh, int depth)
+{
+ struct ext3_extent_idx *idx;
+ struct buffer_head *bh;
+ int metadata = 1;
+ int count = 0;
+ int i, ret = 0;
+ int freed = 0;
+
+ if (depth == 0) {
+ eh->eh_entries = 0;
+ return 0;
+ }
+
+ idx = EXT_FIRST_INDEX(eh);
+
+ count = eh->eh_entries;
+
+ for (i = 1; i <= count; i++) {
+ if (depth > 1) {
+ bh = sb_bread(dest_tree->inode->i_sb, idx->ei_leaf);
+ if (!bh) {
+ ret = -EIO;
+ } else {
+ ret = ext3_ext_remove_index_blocks(handle,
+ dest_tree, EXT_BLOCK_HDR(bh),
+ depth - 1);
+ brelse(bh);
+ }
+ }
+ ext3_mb_free_blocks(handle, dest_tree->inode,
+ idx->ei_leaf, 1, metadata, &freed);
+ eh->eh_entries--;
+ idx++;
+ }
+ return ret;
+}
+
+/**
+ * ext3_ext_alloc_blocks - allocate contiguous block for temporary inode
+ * @handle handle
+ * @inode_dest temporary inode for multiple block allocation
+ * @dest_tree ext3_extents_tree of inode_dest
+ * @iblock file related offset
+ * @total_blocks contiguous blocks count
+ *
+ * If succeed, fuction returns extents-count we got,
+ * otherwise returns err.
+ */
+static int ext3_ext_alloc_blocks (handle_t *handle, struct inode *inode_dest,
+ struct ext3_extents_tree *dest_tree,
+ unsigned long iblock, unsigned long total_blocks)
+{
+ struct ext3_ext_path *path = NULL;
+ struct ext3_extent newex;
+ struct ext3_extent_header *eh = EXT_ROOT_HDR(dest_tree);
+ unsigned long newblock = 0;
+ unsigned long rest = total_blocks;
+ unsigned long alloc_total = 0;
+ int count = 0;
+ int goal = 0;
+ int flag = 0;
+ int err = 0;
+ int err2 = 0;
+ int len = MAX_BLOCKS_LEN;
+ flag |= EXT3_MB_HINT_RESERVED;
+
+ if (MAX_BLOCKS_LEN > total_blocks) {
+ len = total_blocks;
+ }
+
+ /* If we have already held index blocks, remove them. */
+ if (eh->eh_entries != 0) {
+ err2 = ext3_ext_remove_index_blocks(handle, dest_tree,
+ eh, eh->eh_depth);
+ if (err2 < 0) {
+ return err2;
+ }
+ }
+
+ /* Find first extent. */
+ path = ext3_ext_find_extent(dest_tree, iblock, path);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ path = NULL;
+ goto err;
+ }
+
+ goal = ext3_ext_find_goal(inode_dest, path, iblock);
+
+ while (alloc_total != total_blocks) {
+ /* Get contiguous blocks */
+ newblock = ext3_mb_new_blocks(handle, inode_dest, goal,
+ &len, flag, &err);
+ if (newblock == 0) {
+ len = len / 2;
+ if (len == 1) {
+ goto err;
+ }
+ } else {
+ /* Logical */
+ newex.ee_block = cpu_to_le32(alloc_total);
+ /* Physical start */
+ newex.ee_start = cpu_to_le32(newblock);
+ /* Physical-hi start */
+ newex.ee_start_hi = 0;
+ /* Length */
+ newex.ee_len = cpu_to_le32(len);
+
+ alloc_total += len;
+ rest = rest - len;
+ if (rest < len) {
+ len = rest;
+ }
+
+ goal = newblock + len;
+ err = ext3_ext_insert_extent(handle, dest_tree,
+ path, &newex);
+ if (err) {
+ goto err;
+ } else {
+ count++;
+ }
+ }
+ }
+ if (path) {
+ ext3_ext_drop_refs(path);
+ kfree(path);
+ }
+ return count;
+err:
+ /* We have to remove halfway blocks, if we failed. */
+ if (alloc_total != 0) {
+ err2 = ext3_ext_remove_space(dest_tree, iblock, alloc_total);
+ }
+ if (path) {
+ ext3_ext_drop_refs(path);
+ kfree(path);
+ }
+ if (err2 == 0) {
+ return err;
+ } else {
+ return err2;
+ }
+}
+
+/**
+ * ext3_ext_new_extent_tree - allocate contiguous blocks
+ * @tmp_inode: inode of the temporary file
+ * @org_tree: extent tree of the original inode
+ * @dest_tree: extent tree of the temporary inode
+ * @path: the structure holding some info about
+ * original extent tree
+ * @page_offset: starting offset to defrag in pages
+ * @nr_to_read: the number of pages to read
+ *
+ * This function returns 0 if succeeded, otherwise returns error value
+ */
+static int
+ext3_ext_new_extent_tree(struct inode *tmp_inode,
+ struct ext3_extents_tree *org_tree,
+ struct ext3_extents_tree *dest_tree,
+ struct ext3_ext_path *path,
+ pgoff_t page_offset, pgoff_t nr_to_read)
+{
+ struct ext3_extent *ext = NULL;
+ struct ext3_extent_header *eh = NULL;
+ handle_t *handle;
+ unsigned blocks_per_page = PAGE_SIZE >> tmp_inode->i_blkbits;
+ unsigned long tar_start = page_offset * blocks_per_page;
+ unsigned long tar_end =
+ ((page_offset + nr_to_read) * blocks_per_page) - 1;
+ unsigned long seq_blocks = tar_end - tar_start + 1;
+ int sum_org = 0, sum_tmp = 0;
+ unsigned jnum;
+ int ret = 0, err = 0, depth;
+ int last_extent = 0;
+
+ /* (blocks_per_page * count) * (extent_blocks + index_blocks)
+ * + super_block + block_bitmap + group_descriptor
+ * jnum = ext3_ext_writepage_trans_blocks(inode, count) + 3;
+ */
+ /* TODO:
+ * Need to consider the way of calculating journal blocks
+ * because j_max_transaction_buffer may exceed 2048
+ * if we have a deep depth.
+ */
+ jnum = 2048;
+ eh = EXT_ROOT_HDR(dest_tree);
+ eh->eh_depth = 0;
+ handle = ext3_journal_start(tmp_inode, jnum);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto ERR1;
+ }
+
+ ext3_extent_tree_init(handle, dest_tree);
+
+ /* allocate contiguous blocks */
+ if ((sum_tmp = ext3_ext_alloc_blocks(handle, tmp_inode,
+ dest_tree, 0, seq_blocks)) < 0) {
+ ret = sum_tmp;
+ goto ERR2;
+ }
+ depth = EXT_DEPTH(org_tree);
+ ext = path[depth].p_ext;
+
+ while (1) {
+ if (!last_extent)
+ ++sum_org;
+
+ if (tar_end <= le32_to_cpu(ext->ee_block) +
+ le32_to_cpu(ext->ee_len) - 1 ||
+ last_extent) {
+
+ /* fragment decreased */
+ if (sum_org > sum_tmp) {
+ if (tar_end == le32_to_cpu(ext->ee_block) +
+ le32_to_cpu(ext->ee_len) - 1) {
+ /* update path with next extent */
+ if ((last_extent =
+ ext3_ext_next_extent(tmp_inode,
+ path, &ext)) < 0) {
+ ret = last_extent;
+ break;
+ }
+ }
+ } else {
+ /* fragment increased */
+ ret = -ENOSPC;
+ }
+ break;
+ }
+
+ if ((last_extent =
+ ext3_ext_next_extent(tmp_inode,
+ path, &ext)) < 0) {
+ ret = last_extent;
+ break;
+ }
+ }
+
+ERR2:
+ err = ext3_journal_stop(handle);
+ if (ret >= 0)
+ ret = err;
+ERR1:
+ return ret;
+}
+
+/**
+ * ext3_ext_defrag - defrag whole file
+ * @filp: pointer to file
+ * @from: starting offset to defrag in bytes
+ * @defrag_size: size of defrag in bytes
+ *
+ * This function returns the number of pages if succeeded, otherwise
+ * returns error value
+ */
+int
+ext3_ext_defrag(struct file *filp, loff_t from, loff_t defrag_size)
+{
+ struct inode *inode = filp->f_dentry->d_inode, *tmp_inode = NULL;
+ struct ext3_extents_tree org_tree, dest_tree;
+ struct ext3_ext_path *path = NULL;
+ pgoff_t page_offset = from >> PAGE_SHIFT;
+ pgoff_t page_start = page_offset;
+ pgoff_t page_end = (from + defrag_size - 1) >> PAGE_SHIFT;
+ pgoff_t nr_to_read = DEFRAG_PAGES;
+ pgoff_t page_cnt = (defrag_size + PAGE_SIZE -1) >> PAGE_SHIFT;
+ pgoff_t dest_offset = 0;
+ int ret = 0;
+
+ tmp_inode = new_inode(inode->i_sb);
+ if (!tmp_inode) {
+ ret = -ENOMEM;
+ goto ERR1;
+ }
+
+ mutex_lock(&inode->i_mutex);
+ ext3_init_tree_desc(&org_tree, inode);
+ ext3_init_tree_desc(&dest_tree, tmp_inode);
+
+ path = ext3_ext_find_extent(&org_tree, 0, NULL);
+ if (IS_ERR(path)) {
+ ret = PTR_ERR(path);
+ goto ERR2;
+ }
+
+ if ((ret = ext3_ext_new_extent_tree(tmp_inode, &org_tree,
+ &dest_tree, path, page_start, page_cnt)) < 0) {
+ goto ERR3;
+ }
+
+ while (page_offset <= page_end) {
+ if (nr_to_read > page_end - page_offset + 1)
+ nr_to_read = page_end - page_offset + 1;
+
+ /* replace original branches for new branches */
+ if ((ret = ext3_ext_defrag_partial(filp, &org_tree,
+ &dest_tree, page_offset, dest_offset,
+ nr_to_read)) < 0)
+ break;
+
+ page_offset += nr_to_read;
+ dest_offset += nr_to_read;
+ }
+ERR3:
+ if (path) {
+ ext3_ext_drop_refs(path);
+ kfree(path);
+ }
+ERR2:
+ mutex_unlock(&inode->i_mutex);
+ iput(tmp_inode);
+ERR1:
+ return (ret ? ret : ((page_offset - page_start) << PAGE_SHIFT));
+}
+
EXPORT_SYMBOL(ext3_init_tree_desc);
EXPORT_SYMBOL(ext3_mark_inode_dirty);
EXPORT_SYMBOL(ext3_ext_invalidate_cache);
@@ -2353,3 +2760,5 @@ EXPORT_SYMBOL(ext3_ext_insert_extent);
EXPORT_SYMBOL(ext3_ext_walk_space);
EXPORT_SYMBOL(ext3_ext_find_goal);
EXPORT_SYMBOL(ext3_ext_calc_credits_for_insert);
+
+
diff -upNr -X linux-2.6.16.8-alex-org/Documentation/dontdiff linux-2.6.16.8-alex-org/fs/ext3/ioctl.c linux-2.6.16.8-tmp1/fs/ext3/ioctl.c
--- linux-2.6.16.8-alex-org/fs/ext3/ioctl.c 2006-11-08 21:20:26.000000000 +0900
+++ linux-2.6.16.8-tmp1/fs/ext3/ioctl.c 2006-11-08 21:21:41.000000000 +0900
@@ -103,6 +103,7 @@ flags_err:
case EXT3_IOC_GET_EXTENTS:
case EXT3_IOC_GET_TREE_STATS:
case EXT3_IOC_GET_TREE_DEPTH:
+ case EXT3_IOC_DEFRAG:
return ext3_ext_ioctl(inode, filp, cmd, arg);
case EXT3_IOC_GETVERSION:
case EXT3_IOC_GETVERSION_OLD:
diff -upNr -X linux-2.6.16.8-alex-org/Documentation/dontdiff linux-2.6.16.8-alex-org/include/linux/ext3_fs.h linux-2.6.16.8-tmp1/include/linux/ext3_fs.h
--- linux-2.6.16.8-alex-org/include/linux/ext3_fs.h 2006-11-08 21:20:31.000000000 +0900
+++ linux-2.6.16.8-tmp1/include/linux/ext3_fs.h 2006-11-08 21:21:52.000000000 +0900
@@ -229,6 +229,14 @@ struct ext3_new_group_data {
__u32 free_blocks_count;
};

+/* Used for defrag */
+struct ext3_ext_defrag_data {
+ loff_t start_offset; /* start offset to defrag in byte */
+ loff_t defrag_size; /* size of defrag in bytes */
+};
+
+#define DEFRAG_PAGES 128 /* the number of pages to defrag at one time */
+#define MAX_BLOCKS_LEN 16384 /* Maximum length of contiguous blocks */

/*
* ioctl commands
@@ -249,6 +257,7 @@ struct ext3_new_group_data {
#define EXT3_IOC_GET_EXTENTS _IOR('f', 7, long)
#define EXT3_IOC_GET_TREE_DEPTH _IOR('f', 8, long)
#define EXT3_IOC_GET_TREE_STATS _IOR('f', 9, long)
+#define EXT3_IOC_DEFRAG _IOW('f', 10, struct ext3_ext_defrag_data)

/*
* Mount options
@@ -812,6 +821,7 @@ extern void ext3_set_aops(struct inode *
/* ioctl.c */
extern int ext3_ioctl (struct inode *, struct file *, unsigned int,
unsigned long);
+extern int ext3_ext_defrag(struct file *, loff_t, loff_t);

/* namei.c */
extern int ext3_orphan_add(handle_t *, struct inode *);
@@ -882,6 +892,9 @@ extern int ext3_mb_reserve_blocks(struct
extern void ext3_mb_release_blocks(struct super_block *, int);
int __init init_ext3_proc(void);
void exit_ext3_proc(void);
+extern void ext3_mb_free_blocks(handle_t *handle, struct inode *inode,
+ unsigned long block, unsigned long count,
+ int metadata, int *freed);

/* writeback.c */
extern int ext3_wb_writepages(struct address_space *, struct writeback_control *);