* @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.
+ * stores it in *@goal and returns zero.
*/
-static int ext3_find_goal(struct inode *inode, long block, Indirect chain[4],
- Indirect *partial, unsigned long *goal)
+static unsigned long ext3_find_goal(struct inode *inode, long block,
+ Indirect chain[4], Indirect *partial)
{
- struct ext3_inode_info *ei = EXT3_I(inode);
- /* Writer: ->i_next_alloc* */
- if ((block == ei->i_next_alloc_block + 1)&& ei->i_next_alloc_goal) {
- ei->i_next_alloc_block++;
- ei->i_next_alloc_goal++;
- }
- /* Writer: end */
- /* Reader: pointers, ->i_next_alloc* */
- 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 = ext3_find_near(inode, partial);
- return 0;
+ struct ext3_block_alloc_info *block_i = EXT3_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;
}
- /* Reader: end */
- return -EAGAIN;
+
+ return ext3_find_near(inode, partial);
}
/**
* @where: location of missing link
* @num: number of 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
+ * 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. Otherwise (== chain had been changed)
- * we free the new blocks (forgetting their buffer_heads, indeed) and
- * return -EAGAIN.
+ * chain to new block and return 0.
*/
static int ext3_splice_branch(handle_t *handle, struct inode *inode, long block,
{
int i;
int err = 0;
- struct ext3_inode_info *ei = EXT3_I(inode);
+ struct ext3_block_alloc_info *block_i = EXT3_I(inode)->i_block_alloc_info;
/*
* If we're splicing into a [td]indirect block (as opposed to the
if (err)
goto err_out;
}
- /* Verify that place we are splicing to is still there and vacant */
-
- /* Writer: pointers, ->i_next_alloc* */
- if (!verify_chain(chain, where-1) || *where->p)
- /* Writer: end */
- goto changed;
-
/* 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);
- /* Writer: end */
+
+ /*
+ * 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;
+ block_i->last_alloc_physical_block = le32_to_cpu(where[num-1].key);
+ }
/* We are done with atomic stuff, now do the rest of housekeeping */
}
return err;
-changed:
- /*
- * AKPM: if where[i].bh isn't part of the current updating
- * transaction then we explode nastily. Test this code path.
- */
- jbd_debug(1, "the chain changed: try again\n");
- err = -EAGAIN;
-
err_out:
for (i = 1; i < num; i++) {
BUFFER_TRACE(where[i].bh, "call journal_forget");
ext3_journal_forget(handle, where[i].bh);
}
- /* For the normal collision cleanup case, we free up the blocks.
- * On genuine filesystem errors we don't even think about doing
- * that. */
- if (err == -EAGAIN)
- for (i = 0; i < num; i++)
- ext3_free_blocks(handle, inode,
- le32_to_cpu(where[i].key), 1);
return err;
}
unsigned long goal;
int left;
int boundary = 0;
- int depth = ext3_block_to_path(inode, iblock, offsets, &boundary);
+ const int depth = ext3_block_to_path(inode, iblock, offsets, &boundary);
struct ext3_inode_info *ei = EXT3_I(inode);
J_ASSERT(handle != NULL || create == 0);
if (depth == 0)
goto out;
-reread:
partial = ext3_get_branch(inode, depth, offsets, chain, &err);
/* Simplest case - block found, no allocation needed */
if (!partial) {
clear_buffer_new(bh_result);
-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;
+ goto got_it;
}
/* Next simple case - plain lookup or failed read of indirect block */
- if (!create || err == -EIO) {
-cleanup:
+ if (!create || err == -EIO)
+ goto cleanup;
+
+ down(&ei->truncate_sem);
+
+ /*
+ * If the indirect block is missing while we are reading
+ * the chain(ext3_get_branch() returns -EAGAIN err), or
+ * if the chain has been changed after we grab the semaphore,
+ * (either because another process truncated this branch, or
+ * another get_block allocated this branch) re-grab the chain to see if
+ * the request block has been allocated or not.
+ *
+ * Since we already block the truncate/other get_block
+ * at this point, we will have the current copy of the chain when we
+ * splice the branch into the tree.
+ */
+ if (err == -EAGAIN || !verify_chain(chain, partial)) {
while (partial > chain) {
- BUFFER_TRACE(partial->bh, "call brelse");
brelse(partial->bh);
partial--;
}
- BUFFER_TRACE(bh_result, "returned");
-out:
- return err;
+ partial = ext3_get_branch(inode, depth, offsets, chain, &err);
+ if (!partial) {
+ up(&ei->truncate_sem);
+ if (err)
+ goto cleanup;
+ clear_buffer_new(bh_result);
+ goto got_it;
+ }
}
/*
- * 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))
+ ext3_init_block_alloc_info(inode);
- goal = 0;
- down(&ei->truncate_sem);
- if (ext3_find_goal(inode, iblock, chain, partial, &goal) < 0) {
- up(&ei->truncate_sem);
- goto changed;
- }
+ goal = ext3_find_goal(inode, iblock, chain, partial);
left = (chain + depth) - partial;
* Block out ext3_truncate while we alter the tree
*/
err = ext3_alloc_branch(handle, inode, left, goal,
- offsets+(partial-chain), partial);
+ offsets + (partial - chain), partial);
- /* The ext3_splice_branch call will free and forget any buffers
+ /*
+ * The ext3_splice_branch call will free and forget any buffers
* on the new chain if there is a failure, but that risks using
* up transaction credits, especially for bitmaps where the
* credits cannot be returned. Can we handle this somehow? We
- * may need to return -EAGAIN upwards in the worst case. --sct */
+ * may need to return -EAGAIN upwards in the worst case. --sct
+ */
if (!err)
err = ext3_splice_branch(handle, inode, iblock, chain,
partial, left);
- /* i_disksize growing is protected by truncate_sem
- * don't forget to protect it if you're about to implement
- * concurrent ext3_get_block() -bzzz */
+ /*
+ * i_disksize growing is protected by truncate_sem. Don't forget to
+ * protect it if you're about to implement concurrent
+ * ext3_get_block() -bzzz
+ */
if (!err && extend_disksize && inode->i_size > ei->i_disksize)
ei->i_disksize = inode->i_size;
up(&ei->truncate_sem);
- if (err == -EAGAIN)
- goto changed;
if (err)
goto cleanup;
set_buffer_new(bh_result);
- goto got_it;
-
-changed:
+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 */
+cleanup:
while (partial > chain) {
- jbd_debug(1, "buffer chain changed, retrying\n");
- BUFFER_TRACE(partial->bh, "brelsing");
+ BUFFER_TRACE(partial->bh, "call brelse");
brelse(partial->bh);
partial--;
}
- goto reread;
+ BUFFER_TRACE(bh_result, "returned");
+out:
+ return err;
}
static int ext3_get_block(struct inode *inode, sector_t iblock,
ret = PTR_ERR(handle);
goto out;
}
- ret = block_prepare_write(page, from, to, ext3_get_block);
+ if (test_opt(inode->i_sb, NOBH))
+ ret = nobh_prepare_write(page, from, to, ext3_get_block);
+ else
+ ret = block_prepare_write(page, from, to, ext3_get_block);
if (ret)
goto prepare_write_failed;
new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
if (new_i_size > EXT3_I(inode)->i_disksize)
EXT3_I(inode)->i_disksize = new_i_size;
- ret = generic_commit_write(file, page, from, to);
+
+ if (test_opt(inode->i_sb, NOBH))
+ ret = nobh_commit_write(file, page, from, to);
+ else
+ ret = generic_commit_write(file, page, from, to);
+
ret2 = ext3_journal_stop(handle);
if (!ret)
ret = ret2;
goto out_fail;
}
- ret = block_write_full_page(page, ext3_get_block, wbc);
+ if (test_opt(inode->i_sb, NOBH))
+ ret = nobh_writepage(page, ext3_get_block, wbc);
+ else
+ ret = block_write_full_page(page, ext3_get_block, wbc);
+
err = ext3_journal_stop(handle);
if (!ret)
ret = err;
journal_t *journal = EXT3_JOURNAL(page->mapping->host);
WARN_ON(PageChecked(page));
+ if (!page_has_buffers(page))
+ return 0;
return journal_try_to_free_buffers(journal, page, wait);
}
unsigned blocksize, iblock, length, pos;
struct inode *inode = mapping->host;
struct buffer_head *bh;
- int err;
+ int err = 0;
void *kaddr;
blocksize = inode->i_sb->s_blocksize;
length = blocksize - (offset & (blocksize - 1));
iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
+ /*
+ * For "nobh" option, we can only work if we don't need to
+ * read-in the page - otherwise we create buffers to do the IO.
+ */
+ if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH)) {
+ if (PageUptodate(page)) {
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr + offset, 0, length);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+ set_page_dirty(page);
+ goto unlock;
+ }
+ }
+
if (!page_has_buffers(page))
create_empty_buffers(page, blocksize, 0);
if (ext3_inode_is_fast_symlink(inode))
return;
- ext3_discard_reservation(inode);
-
/*
* We have to lock the EOF page here, because lock_page() nests
* outside journal_start().
case EXT3_TIND_BLOCK:
;
}
+
+ ext3_discard_reservation(inode);
+
up(&ei->truncate_sem);
inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
ext3_mark_inode_dirty(handle, inode);
ei->i_acl = EXT3_ACL_NOT_CACHED;
ei->i_default_acl = EXT3_ACL_NOT_CACHED;
#endif
- ei->i_rsv_window.rsv_end = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
+ ei->i_block_alloc_info = NULL;
if (__ext3_get_inode_loc(inode, &iloc, 0))
goto bad_inode;
inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
ei->i_state = 0;
- ei->i_next_alloc_block = 0;
- ei->i_next_alloc_goal = 0;
ei->i_dir_start_lookup = 0;
ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
/* We now have enough fields to check if the inode was active or not.
ei->i_disksize = inode->i_size;
inode->i_generation = le32_to_cpu(raw_inode->i_generation);
ei->i_block_group = iloc.block_group;
- ei->i_rsv_window.rsv_start = 0;
- ei->i_rsv_window.rsv_end= 0;
- atomic_set(&ei->i_rsv_window.rsv_goal_size, EXT3_DEFAULT_RESERVE_BLOCKS);
- seqlock_init(&ei->i_rsv_window.rsv_seqlock);
/*
* NOTE! The in-memory inode i_data array is in little-endian order
* even on big-endian machines: we do NOT byteswap the block numbers!
git://git.onelab.eu / linux-2.6.git / blobdiff