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-rw-r--r--fs/ext2/inode.c524
1 files changed, 308 insertions, 216 deletions
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 8481817..b1ab32a 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -54,19 +54,6 @@ static inline int ext2_inode_is_fast_symlink(struct inode *inode)
}
/*
- * Called at each iput().
- *
- * The inode may be "bad" if ext2_read_inode() saw an error from
- * ext2_get_inode(), so we need to check that to avoid freeing random disk
- * blocks.
- */
-void ext2_put_inode(struct inode *inode)
-{
- if (!is_bad_inode(inode))
- ext2_discard_prealloc(inode);
-}
-
-/*
* Called at the last iput() if i_nlink is zero.
*/
void ext2_delete_inode (struct inode * inode)
@@ -89,61 +76,6 @@ no_delete:
clear_inode(inode); /* We must guarantee clearing of inode... */
}
-void ext2_discard_prealloc (struct inode * inode)
-{
-#ifdef EXT2_PREALLOCATE
- struct ext2_inode_info *ei = EXT2_I(inode);
- write_lock(&ei->i_meta_lock);
- if (ei->i_prealloc_count) {
- unsigned short total = ei->i_prealloc_count;
- unsigned long block = ei->i_prealloc_block;
- ei->i_prealloc_count = 0;
- ei->i_prealloc_block = 0;
- write_unlock(&ei->i_meta_lock);
- ext2_free_blocks (inode, block, total);
- return;
- } else
- write_unlock(&ei->i_meta_lock);
-#endif
-}
-
-static int ext2_alloc_block (struct inode * inode, unsigned long goal, int *err)
-{
-#ifdef EXT2FS_DEBUG
- static unsigned long alloc_hits, alloc_attempts;
-#endif
- unsigned long result;
-
-
-#ifdef EXT2_PREALLOCATE
- struct ext2_inode_info *ei = EXT2_I(inode);
- write_lock(&ei->i_meta_lock);
- if (ei->i_prealloc_count &&
- (goal == ei->i_prealloc_block || goal + 1 == ei->i_prealloc_block))
- {
- result = ei->i_prealloc_block++;
- ei->i_prealloc_count--;
- write_unlock(&ei->i_meta_lock);
- ext2_debug ("preallocation hit (%lu/%lu).\n",
- ++alloc_hits, ++alloc_attempts);
- } else {
- write_unlock(&ei->i_meta_lock);
- ext2_discard_prealloc (inode);
- ext2_debug ("preallocation miss (%lu/%lu).\n",
- alloc_hits, ++alloc_attempts);
- if (S_ISREG(inode->i_mode))
- result = ext2_new_block (inode, goal,
- &ei->i_prealloc_count,
- &ei->i_prealloc_block, err);
- else
- result = ext2_new_block(inode, goal, NULL, NULL, err);
- }
-#else
- result = ext2_new_block (inode, goal, 0, 0, err);
-#endif
- return result;
-}
-
typedef struct {
__le32 *p;
__le32 key;
@@ -228,7 +160,8 @@ static int ext2_block_to_path(struct inode *inode,
ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big");
}
if (boundary)
- *boundary = (i_block & (ptrs - 1)) == (final - 1);
+ *boundary = final - 1 - (i_block & (ptrs - 1));
+
return n;
}
@@ -355,39 +288,129 @@ static unsigned long ext2_find_near(struct inode *inode, Indirect *ind)
* @block: block we want
* @chain: chain of indirect blocks
* @partial: pointer to the last triple within a chain
- * @goal: place to store the result.
*
- * Normally this function find the prefered place for block allocation,
- * stores it in *@goal and returns zero. If the branch had been changed
- * under us we return -EAGAIN.
+ * Returns preferred place for a block (the goal).
*/
static inline int ext2_find_goal(struct inode *inode,
long block,
Indirect chain[4],
- Indirect *partial,
- unsigned long *goal)
+ Indirect *partial)
{
- struct ext2_inode_info *ei = EXT2_I(inode);
- write_lock(&ei->i_meta_lock);
- if ((block == ei->i_next_alloc_block + 1) && ei->i_next_alloc_goal) {
- ei->i_next_alloc_block++;
- ei->i_next_alloc_goal++;
- }
- if (verify_chain(chain, partial)) {
- /*
- * try the heuristic for sequential allocation,
- * failing that at least try to get decent locality.
- */
- if (block == ei->i_next_alloc_block)
- *goal = ei->i_next_alloc_goal;
- if (!*goal)
- *goal = ext2_find_near(inode, partial);
- write_unlock(&ei->i_meta_lock);
- return 0;
+ struct ext2_block_alloc_info *block_i;
+
+ block_i = EXT2_I(inode)->i_block_alloc_info;
+
+ /*
+ * try the heuristic for sequential allocation,
+ * failing that at least try to get decent locality.
+ */
+ if (block_i && (block == block_i->last_alloc_logical_block + 1)
+ && (block_i->last_alloc_physical_block != 0)) {
+ return block_i->last_alloc_physical_block + 1;
}
- write_unlock(&ei->i_meta_lock);
- return -EAGAIN;
+
+ return ext2_find_near(inode, partial);
+}
+
+/**
+ * ext2_blks_to_allocate: Look up the block map and count the number
+ * of direct blocks need to be allocated for the given branch.
+ *
+ * @branch: chain of indirect blocks
+ * @k: number of blocks need for indirect blocks
+ * @blks: number of data blocks to be mapped.
+ * @blocks_to_boundary: the offset in the indirect block
+ *
+ * return the total number of blocks to be allocate, including the
+ * direct and indirect blocks.
+ */
+static int
+ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks,
+ int blocks_to_boundary)
+{
+ unsigned long count = 0;
+
+ /*
+ * Simple case, [t,d]Indirect block(s) has not allocated yet
+ * then it's clear blocks on that path have not allocated
+ */
+ if (k > 0) {
+ /* right now don't hanel cross boundary allocation */
+ if (blks < blocks_to_boundary + 1)
+ count += blks;
+ else
+ count += blocks_to_boundary + 1;
+ return count;
+ }
+
+ count++;
+ while (count < blks && count <= blocks_to_boundary
+ && le32_to_cpu(*(branch[0].p + count)) == 0) {
+ count++;
+ }
+ return count;
+}
+
+/**
+ * ext2_alloc_blocks: multiple allocate blocks needed for a branch
+ * @indirect_blks: the number of blocks need to allocate for indirect
+ * blocks
+ *
+ * @new_blocks: on return it will store the new block numbers for
+ * the indirect blocks(if needed) and the first direct block,
+ * @blks: on return it will store the total number of allocated
+ * direct blocks
+ */
+static int ext2_alloc_blocks(struct inode *inode,
+ ext2_fsblk_t goal, int indirect_blks, int blks,
+ ext2_fsblk_t new_blocks[4], int *err)
+{
+ int target, i;
+ unsigned long count = 0;
+ int index = 0;
+ ext2_fsblk_t current_block = 0;
+ int ret = 0;
+
+ /*
+ * Here we try to allocate the requested multiple blocks at once,
+ * on a best-effort basis.
+ * To build a branch, we should allocate blocks for
+ * the indirect blocks(if not allocated yet), and at least
+ * the first direct block of this branch. That's the
+ * minimum number of blocks need to allocate(required)
+ */
+ target = blks + indirect_blks;
+
+ while (1) {
+ count = target;
+ /* allocating blocks for indirect blocks and direct blocks */
+ current_block = ext2_new_blocks(inode,goal,&count,err);
+ if (*err)
+ goto failed_out;
+
+ target -= count;
+ /* allocate blocks for indirect blocks */
+ while (index < indirect_blks && count) {
+ new_blocks[index++] = current_block++;
+ count--;
+ }
+
+ if (count > 0)
+ break;
+ }
+
+ /* save the new block number for the first direct block */
+ new_blocks[index] = current_block;
+
+ /* total number of blocks allocated for direct blocks */
+ ret = count;
+ *err = 0;
+ return ret;
+failed_out:
+ for (i = 0; i <index; i++)
+ ext2_free_blocks(inode, new_blocks[i], 1);
+ return ret;
}
/**
@@ -416,39 +439,49 @@ static inline int ext2_find_goal(struct inode *inode,
*/
static int ext2_alloc_branch(struct inode *inode,
- int num,
- unsigned long goal,
- int *offsets,
- Indirect *branch)
+ int indirect_blks, int *blks, ext2_fsblk_t goal,
+ int *offsets, Indirect *branch)
{
int blocksize = inode->i_sb->s_blocksize;
- int n = 0;
- int err;
- int i;
- int parent = ext2_alloc_block(inode, goal, &err);
-
- branch[0].key = cpu_to_le32(parent);
- if (parent) for (n = 1; n < num; n++) {
- struct buffer_head *bh;
- /* Allocate the next block */
- int nr = ext2_alloc_block(inode, parent, &err);
- if (!nr)
- break;
- branch[n].key = cpu_to_le32(nr);
+ int i, n = 0;
+ int err = 0;
+ struct buffer_head *bh;
+ int num;
+ ext2_fsblk_t new_blocks[4];
+ ext2_fsblk_t current_block;
+
+ num = ext2_alloc_blocks(inode, goal, indirect_blks,
+ *blks, new_blocks, &err);
+ if (err)
+ return err;
+
+ branch[0].key = cpu_to_le32(new_blocks[0]);
+ /*
+ * metadata blocks and data blocks are allocated.
+ */
+ for (n = 1; n <= indirect_blks; n++) {
/*
- * Get buffer_head for parent block, zero it out and set
- * the pointer to new one, then send parent to disk.
+ * Get buffer_head for parent block, zero it out
+ * and set the pointer to new one, then send
+ * parent to disk.
*/
- bh = sb_getblk(inode->i_sb, parent);
- if (!bh) {
- err = -EIO;
- break;
- }
+ bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
+ branch[n].bh = bh;
lock_buffer(bh);
memset(bh->b_data, 0, blocksize);
- branch[n].bh = bh;
branch[n].p = (__le32 *) bh->b_data + offsets[n];
+ branch[n].key = cpu_to_le32(new_blocks[n]);
*branch[n].p = branch[n].key;
+ if ( n == indirect_blks) {
+ current_block = new_blocks[n];
+ /*
+ * End of chain, update the last new metablock of
+ * the chain to point to the new allocated
+ * data blocks numbers
+ */
+ for (i=1; i < num; i++)
+ *(branch[n].p + i) = cpu_to_le32(++current_block);
+ }
set_buffer_uptodate(bh);
unlock_buffer(bh);
mark_buffer_dirty_inode(bh, inode);
@@ -458,77 +491,68 @@ static int ext2_alloc_branch(struct inode *inode,
*/
if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
sync_dirty_buffer(bh);
- parent = nr;
}
- if (n == num)
- return 0;
-
- /* Allocation failed, free what we already allocated */
- for (i = 1; i < n; i++)
- bforget(branch[i].bh);
- for (i = 0; i < n; i++)
- ext2_free_blocks(inode, le32_to_cpu(branch[i].key), 1);
+ *blks = num;
return err;
}
/**
- * ext2_splice_branch - splice the allocated branch onto inode.
- * @inode: owner
- * @block: (logical) number of block we are adding
- * @chain: chain of indirect blocks (with a missing link - see
- * ext2_alloc_branch)
- * @where: location of missing link
- * @num: number of blocks we are adding
+ * ext2_splice_branch - splice the allocated branch onto inode.
+ * @inode: owner
+ * @block: (logical) number of block we are adding
+ * @chain: chain of indirect blocks (with a missing link - see
+ * ext2_alloc_branch)
+ * @where: location of missing link
+ * @num: number of indirect blocks we are adding
+ * @blks: number of direct blocks we are adding
*
- * This function verifies that chain (up to the missing link) had not
- * changed, fills the missing link and does all housekeeping needed in
- * inode (->i_blocks, etc.). In case of success we end up with the full
- * chain to new block and return 0. Otherwise (== chain had been changed)
- * we free the new blocks (forgetting their buffer_heads, indeed) and
- * return -EAGAIN.
+ * This function fills the missing link and does all housekeeping needed in
+ * inode (->i_blocks, etc.). In case of success we end up with the full
+ * chain to new block and return 0.
*/
-
-static inline int ext2_splice_branch(struct inode *inode,
- long block,
- Indirect chain[4],
- Indirect *where,
- int num)
+static void ext2_splice_branch(struct inode *inode,
+ long block, Indirect *where, int num, int blks)
{
- struct ext2_inode_info *ei = EXT2_I(inode);
int i;
+ struct ext2_block_alloc_info *block_i;
+ ext2_fsblk_t current_block;
- /* Verify that place we are splicing to is still there and vacant */
-
- write_lock(&ei->i_meta_lock);
- if (!verify_chain(chain, where-1) || *where->p)
- goto changed;
+ block_i = EXT2_I(inode)->i_block_alloc_info;
+ /* XXX LOCKING probably should have i_meta_lock ?*/
/* That's it */
*where->p = where->key;
- ei->i_next_alloc_block = block;
- ei->i_next_alloc_goal = le32_to_cpu(where[num-1].key);
- write_unlock(&ei->i_meta_lock);
+ /*
+ * Update the host buffer_head or inode to point to more just allocated
+ * direct blocks blocks
+ */
+ if (num == 0 && blks > 1) {
+ current_block = le32_to_cpu(where->key) + 1;
+ for (i = 1; i < blks; i++)
+ *(where->p + i ) = cpu_to_le32(current_block++);
+ }
- /* We are done with atomic stuff, now do the rest of housekeeping */
+ /*
+ * update the most recently allocated logical & physical block
+ * in i_block_alloc_info, to assist find the proper goal block for next
+ * allocation
+ */
+ if (block_i) {
+ block_i->last_alloc_logical_block = block + blks - 1;
+ block_i->last_alloc_physical_block =
+ le32_to_cpu(where[num].key) + blks - 1;
+ }
- inode->i_ctime = CURRENT_TIME_SEC;
+ /* We are done with atomic stuff, now do the rest of housekeeping */
/* had we spliced it onto indirect block? */
if (where->bh)
mark_buffer_dirty_inode(where->bh, inode);
+ inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
- return 0;
-
-changed:
- write_unlock(&ei->i_meta_lock);
- for (i = 1; i < num; i++)
- bforget(where[i].bh);
- for (i = 0; i < num; i++)
- ext2_free_blocks(inode, le32_to_cpu(where[i].key), 1);
- return -EAGAIN;
}
/*
@@ -542,64 +566,99 @@ changed:
* That has a nice additional property: no special recovery from the failed
* allocations is needed - we simply release blocks and do not touch anything
* reachable from inode.
+ *
+ * `handle' can be NULL if create == 0.
+ *
+ * The BKL may not be held on entry here. Be sure to take it early.
+ * return > 0, # of blocks mapped or allocated.
+ * return = 0, if plain lookup failed.
+ * return < 0, error case.
*/
-
-int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
+static int ext2_get_blocks(struct inode *inode,
+ sector_t iblock, unsigned long maxblocks,
+ struct buffer_head *bh_result,
+ int create)
{
int err = -EIO;
int offsets[4];
Indirect chain[4];
Indirect *partial;
- unsigned long goal;
- int left;
- int boundary = 0;
- int depth = ext2_block_to_path(inode, iblock, offsets, &boundary);
+ ext2_fsblk_t goal;
+ int indirect_blks;
+ int blocks_to_boundary = 0;
+ int depth;
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ int count = 0;
+ ext2_fsblk_t first_block = 0;
- if (depth == 0)
- goto out;
+ depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
+ if (depth == 0)
+ return (err);
reread:
partial = ext2_get_branch(inode, depth, offsets, chain, &err);
/* Simplest case - block found, no allocation needed */
if (!partial) {
-got_it:
- map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
- if (boundary)
- set_buffer_boundary(bh_result);
- /* Clean up and exit */
- partial = chain+depth-1; /* the whole chain */
- goto cleanup;
+ first_block = le32_to_cpu(chain[depth - 1].key);
+ clear_buffer_new(bh_result); /* What's this do? */
+ count++;
+ /*map more blocks*/
+ while (count < maxblocks && count <= blocks_to_boundary) {
+ ext2_fsblk_t blk;
+
+ if (!verify_chain(chain, partial)) {
+ /*
+ * Indirect block might be removed by
+ * truncate while we were reading it.
+ * Handling of that case: forget what we've
+ * got now, go to reread.
+ */
+ count = 0;
+ goto changed;
+ }
+ blk = le32_to_cpu(*(chain[depth-1].p + count));
+ if (blk == first_block + count)
+ count++;
+ else
+ break;
+ }
+ goto got_it;
}
/* Next simple case - plain lookup or failed read of indirect block */
- if (!create || err == -EIO) {
-cleanup:
- while (partial > chain) {
- brelse(partial->bh);
- partial--;
- }
-out:
- return err;
- }
+ if (!create || err == -EIO)
+ goto cleanup;
+
+ mutex_lock(&ei->truncate_mutex);
/*
- * Indirect block might be removed by truncate while we were
- * reading it. Handling of that case (forget what we've got and
- * reread) is taken out of the main path.
- */
- if (err == -EAGAIN)
- goto changed;
+ * Okay, we need to do block allocation. Lazily initialize the block
+ * allocation info here if necessary
+ */
+ if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
+ ext2_init_block_alloc_info(inode);
- goal = 0;
- if (ext2_find_goal(inode, iblock, chain, partial, &goal) < 0)
- goto changed;
+ goal = ext2_find_goal(inode, iblock, chain, partial);
- left = (chain + depth) - partial;
- err = ext2_alloc_branch(inode, left, goal,
- offsets+(partial-chain), partial);
- if (err)
+ /* the number of blocks need to allocate for [d,t]indirect blocks */
+ indirect_blks = (chain + depth) - partial - 1;
+ /*
+ * Next look up the indirect map to count the totoal number of
+ * direct blocks to allocate for this branch.
+ */
+ count = ext2_blks_to_allocate(partial, indirect_blks,
+ maxblocks, blocks_to_boundary);
+ /*
+ * XXX ???? Block out ext2_truncate while we alter the tree
+ */
+ err = ext2_alloc_branch(inode, indirect_blks, &count, goal,
+ offsets + (partial - chain), partial);
+
+ if (err) {
+ mutex_unlock(&ei->truncate_mutex);
goto cleanup;
+ }
if (ext2_use_xip(inode->i_sb)) {
/*
@@ -607,16 +666,28 @@ out:
*/
err = ext2_clear_xip_target (inode,
le32_to_cpu(chain[depth-1].key));
- if (err)
+ if (err) {
+ mutex_unlock(&ei->truncate_mutex);
goto cleanup;
+ }
}
- if (ext2_splice_branch(inode, iblock, chain, partial, left) < 0)
- goto changed;
-
+ ext2_splice_branch(inode, iblock, partial, indirect_blks, count);
+ mutex_unlock(&ei->truncate_mutex);
set_buffer_new(bh_result);
- goto got_it;
-
+got_it:
+ map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
+ if (count > blocks_to_boundary)
+ set_buffer_boundary(bh_result);
+ err = count;
+ /* Clean up and exit */
+ partial = chain + depth - 1; /* the whole chain */
+cleanup:
+ while (partial > chain) {
+ brelse(partial->bh);
+ partial--;
+ }
+ return err;
changed:
while (partial > chain) {
brelse(partial->bh);
@@ -625,6 +696,19 @@ changed:
goto reread;
}
+int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
+{
+ unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
+ int ret = ext2_get_blocks(inode, iblock, max_blocks,
+ bh_result, create);
+ if (ret > 0) {
+ bh_result->b_size = (ret << inode->i_blkbits);
+ ret = 0;
+ }
+ return ret;
+
+}
+
static int ext2_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page, ext2_get_block, wbc);
@@ -913,9 +997,10 @@ static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int de
ext2_free_data(inode, p, q);
}
-void ext2_truncate (struct inode * inode)
+void ext2_truncate(struct inode *inode)
{
__le32 *i_data = EXT2_I(inode)->i_data;
+ struct ext2_inode_info *ei = EXT2_I(inode);
int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
int offsets[4];
Indirect chain[4];
@@ -933,8 +1018,6 @@ void ext2_truncate (struct inode * inode)
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
return;
- ext2_discard_prealloc(inode);
-
blocksize = inode->i_sb->s_blocksize;
iblock = (inode->i_size + blocksize-1)
>> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
@@ -952,6 +1035,12 @@ void ext2_truncate (struct inode * inode)
if (n == 0)
return;
+ /*
+ * From here we block out all ext2_get_block() callers who want to
+ * modify the block allocation tree.
+ */
+ mutex_lock(&ei->truncate_mutex);
+
if (n == 1) {
ext2_free_data(inode, i_data+offsets[0],
i_data + EXT2_NDIR_BLOCKS);
@@ -1004,6 +1093,10 @@ do_indirects:
case EXT2_TIND_BLOCK:
;
}
+
+ ext2_discard_reservation(inode);
+
+ mutex_unlock(&ei->truncate_mutex);
inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
if (inode_needs_sync(inode)) {
sync_mapping_buffers(inode->i_mapping);
@@ -1104,6 +1197,8 @@ void ext2_read_inode (struct inode * inode)
ei->i_acl = EXT2_ACL_NOT_CACHED;
ei->i_default_acl = EXT2_ACL_NOT_CACHED;
#endif
+ ei->i_block_alloc_info = NULL;
+
if (IS_ERR(raw_inode))
goto bad_inode;
@@ -1145,9 +1240,6 @@ void ext2_read_inode (struct inode * inode)
ei->i_dtime = 0;
inode->i_generation = le32_to_cpu(raw_inode->i_generation);
ei->i_state = 0;
- ei->i_next_alloc_block = 0;
- ei->i_next_alloc_goal = 0;
- ei->i_prealloc_count = 0;
ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
ei->i_dir_start_lookup = 0;
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