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ext4: Simplify delalloc implementation by removing mpd.get_block
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This parameter was always set to ext4_da_get_block_write().

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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Theodore Ts'o committed Feb 23, 2009
1 parent 722bde6 commit ed5bde0
Showing 1 changed file with 58 additions and 67 deletions.
125 changes: 58 additions & 67 deletions fs/ext4/inode.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1705,7 +1705,6 @@ struct mpage_da_data {
struct inode *inode;
struct buffer_head lbh; /* extent of blocks */
unsigned long first_page, next_page; /* extent of pages */
get_block_t *get_block;
struct writeback_control *wbc;
int io_done;
int pages_written;
Expand All @@ -1719,7 +1718,6 @@ struct mpage_da_data {
* @mpd->inode: inode
* @mpd->first_page: first page of the extent
* @mpd->next_page: page after the last page of the extent
* @mpd->get_block: the filesystem's block mapper function
*
* By the time mpage_da_submit_io() is called we expect all blocks
* to be allocated. this may be wrong if allocation failed.
Expand Down Expand Up @@ -1929,16 +1927,60 @@ static void ext4_print_free_blocks(struct inode *inode)
return;
}

#define EXT4_DELALLOC_RSVED 1
static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
int ret;
unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
loff_t disksize = EXT4_I(inode)->i_disksize;
handle_t *handle = NULL;

handle = ext4_journal_current_handle();
BUG_ON(!handle);
ret = ext4_get_blocks_wrap(handle, inode, iblock, max_blocks,
bh_result, create, 0, EXT4_DELALLOC_RSVED);
if (ret <= 0)
return ret;

bh_result->b_size = (ret << inode->i_blkbits);

if (ext4_should_order_data(inode)) {
int retval;
retval = ext4_jbd2_file_inode(handle, inode);
if (retval)
/*
* Failed to add inode for ordered mode. Don't
* update file size
*/
return retval;
}

/*
* Update on-disk size along with block allocation we don't
* use 'extend_disksize' as size may change within already
* allocated block -bzzz
*/
disksize = ((loff_t) iblock + ret) << inode->i_blkbits;
if (disksize > i_size_read(inode))
disksize = i_size_read(inode);
if (disksize > EXT4_I(inode)->i_disksize) {
ext4_update_i_disksize(inode, disksize);
ret = ext4_mark_inode_dirty(handle, inode);
return ret;
}
return 0;
}

/*
* mpage_da_map_blocks - go through given space
*
* @mpd->lbh - bh describing space
* @mpd->get_block - the filesystem's block mapper function
*
* The function skips space we know is already mapped to disk blocks.
*
*/
static int mpage_da_map_blocks(struct mpage_da_data *mpd)
static int mpage_da_map_blocks(struct mpage_da_data *mpd)
{
int err = 0;
struct buffer_head new;
Expand All @@ -1960,30 +2002,29 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd)
*/
if (!new.b_size)
return 0;
err = mpd->get_block(mpd->inode, next, &new, 1);
if (err) {

/* If get block returns with error
* we simply return. Later writepage
* will redirty the page and writepages
* will find the dirty page again
err = ext4_da_get_block_write(mpd->inode, next, &new, 1);
if (err) {
/*
* If get block returns with error we simply
* return. Later writepage will redirty the page and
* writepages will find the dirty page again
*/
if (err == -EAGAIN)
return 0;

if (err == -ENOSPC &&
ext4_count_free_blocks(mpd->inode->i_sb)) {
ext4_count_free_blocks(mpd->inode->i_sb)) {
mpd->retval = err;
return 0;
}

/*
* get block failure will cause us
* to loop in writepages. Because
* a_ops->writepage won't be able to
* make progress. The page will be redirtied
* by writepage and writepages will again
* try to write the same.
* get block failure will cause us to loop in
* writepages, because a_ops->writepage won't be able
* to make progress. The page will be redirtied by
* writepage and writepages will again try to write
* the same.
*/
printk(KERN_EMERG "%s block allocation failed for inode %lu "
"at logical offset %llu with max blocks "
Expand Down Expand Up @@ -2212,7 +2253,6 @@ static int __mpage_da_writepage(struct page *page,
*
* @mapping: address space structure to write
* @wbc: subtract the number of written pages from *@wbc->nr_to_write
* @get_block: the filesystem's block mapper function.
*
* This is a library function, which implements the writepages()
* address_space_operation.
Expand All @@ -2223,9 +2263,6 @@ static int mpage_da_writepages(struct address_space *mapping,
{
int ret;

if (!mpd->get_block)
return generic_writepages(mapping, wbc);

mpd->lbh.b_size = 0;
mpd->lbh.b_state = 0;
mpd->lbh.b_blocknr = 0;
Expand Down Expand Up @@ -2289,51 +2326,6 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,

return ret;
}
#define EXT4_DELALLOC_RSVED 1
static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
int ret;
unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
loff_t disksize = EXT4_I(inode)->i_disksize;
handle_t *handle = NULL;

handle = ext4_journal_current_handle();
BUG_ON(!handle);
ret = ext4_get_blocks_wrap(handle, inode, iblock, max_blocks,
bh_result, create, 0, EXT4_DELALLOC_RSVED);
if (ret > 0) {

bh_result->b_size = (ret << inode->i_blkbits);

if (ext4_should_order_data(inode)) {
int retval;
retval = ext4_jbd2_file_inode(handle, inode);
if (retval)
/*
* Failed to add inode for ordered
* mode. Don't update file size
*/
return retval;
}

/*
* Update on-disk size along with block allocation
* we don't use 'extend_disksize' as size may change
* within already allocated block -bzzz
*/
disksize = ((loff_t) iblock + ret) << inode->i_blkbits;
if (disksize > i_size_read(inode))
disksize = i_size_read(inode);
if (disksize > EXT4_I(inode)->i_disksize) {
ext4_update_i_disksize(inode, disksize);
ret = ext4_mark_inode_dirty(handle, inode);
return ret;
}
ret = 0;
}
return ret;
}

static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh)
{
Expand Down Expand Up @@ -2584,7 +2576,6 @@ static int ext4_da_writepages(struct address_space *mapping,
dump_stack();
goto out_writepages;
}
mpd.get_block = ext4_da_get_block_write;
ret = mpage_da_writepages(mapping, wbc, &mpd);

ext4_journal_stop(handle);
Expand Down

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