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Message-Id: <1272927081-12694-2-git-send-email-tytso@mit.edu>
Date: Mon, 3 May 2010 18:51:21 -0400
From: Theodore Ts'o <tytso@....edu>
To: Ext4 Developers List <linux-ext4@...r.kernel.org>
Cc: Theodore Ts'o <tytso@....edu>
Subject: [PATCH, RFC 2/2] ext4: Convert callers of ext4_get_blocks() to use ext4_map_blocks()
This saves a huge amount of stack space by avoiding unnecesary struct
buffer_head's from being allocated on the stack.
In addition, to make the code easier to understand, collapse and
refactor ext4_get_block(), ext4_get_block_write(),
noalloc_get_block_write(), into a single function.
Signed-off-by: "Theodore Ts'o" <tytso@....edu>
---
fs/ext4/dir.c | 12 +-
fs/ext4/ext4.h | 2 +-
fs/ext4/extents.c | 40 +++----
fs/ext4/inode.c | 342 +++++++++++++++++++++--------------------------------
4 files changed, 158 insertions(+), 238 deletions(-)
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 86cb6d8..e3f2700 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -128,14 +128,14 @@ static int ext4_readdir(struct file *filp,
offset = filp->f_pos & (sb->s_blocksize - 1);
while (!error && !stored && filp->f_pos < inode->i_size) {
- ext4_lblk_t blk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb);
- struct buffer_head map_bh;
+ struct ext4_map_blocks map;
struct buffer_head *bh = NULL;
- map_bh.b_state = 0;
- err = ext4_get_blocks(NULL, inode, blk, 1, &map_bh, 0);
+ map.m_lblk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb);
+ map.m_len = 1;
+ err = ext4_map_blocks(NULL, inode, &map, 0);
if (err > 0) {
- pgoff_t index = map_bh.b_blocknr >>
+ pgoff_t index = map.m_pblk >>
(PAGE_CACHE_SHIFT - inode->i_blkbits);
if (!ra_has_index(&filp->f_ra, index))
page_cache_sync_readahead(
@@ -143,7 +143,7 @@ static int ext4_readdir(struct file *filp,
&filp->f_ra, filp,
index, 1);
filp->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
- bh = ext4_bread(NULL, inode, blk, 0, &err);
+ bh = ext4_bread(NULL, inode, map.m_lblk, 0, &err);
}
/*
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 8dfc70b..08f541b 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -139,7 +139,7 @@ struct ext4_allocation_request {
#define EXT4_MAP_UNINIT (1 << BH_Uninit)
#define EXT4_MAP_FLAGS (EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
- EXT4_MAP_UNINIT);
+ EXT4_MAP_UNINIT)
struct ext4_map_blocks {
ext4_fsblk_t m_pblk;
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 005dce9..2282f40 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3667,13 +3667,12 @@ static void ext4_falloc_update_inode(struct inode *inode,
long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
{
handle_t *handle;
- ext4_lblk_t block;
loff_t new_size;
unsigned int max_blocks;
int ret = 0;
int ret2 = 0;
int retries = 0;
- struct buffer_head map_bh;
+ struct ext4_map_blocks map;
unsigned int credits, blkbits = inode->i_blkbits;
/*
@@ -3687,13 +3686,13 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
if (S_ISDIR(inode->i_mode))
return -ENODEV;
- block = offset >> blkbits;
+ map.m_lblk = offset >> blkbits;
/*
* We can't just convert len to max_blocks because
* If blocksize = 4096 offset = 3072 and len = 2048
*/
max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
- - block;
+ - map.m_lblk;
/*
* credits to insert 1 extent into extent tree
*/
@@ -3701,16 +3700,14 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
mutex_lock(&inode->i_mutex);
retry:
while (ret >= 0 && ret < max_blocks) {
- block = block + ret;
- max_blocks = max_blocks - ret;
+ map.m_lblk = map.m_lblk + ret;
+ map.m_len = max_blocks = max_blocks - ret;
handle = ext4_journal_start(inode, credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
break;
}
- map_bh.b_state = 0;
- ret = ext4_get_blocks(handle, inode, block,
- max_blocks, &map_bh,
+ ret = ext4_map_blocks(handle, inode, &map,
EXT4_GET_BLOCKS_CREATE_UNINIT_EXT);
if (ret <= 0) {
#ifdef EXT4FS_DEBUG
@@ -3724,14 +3721,14 @@ retry:
ret2 = ext4_journal_stop(handle);
break;
}
- if ((block + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
+ if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
blkbits) >> blkbits))
new_size = offset + len;
else
- new_size = (block + ret) << blkbits;
+ new_size = (map.m_lblk + ret) << blkbits;
ext4_falloc_update_inode(inode, mode, new_size,
- buffer_new(&map_bh));
+ (map.m_flags & EXT4_MAP_NEW));
ext4_mark_inode_dirty(handle, inode);
ret2 = ext4_journal_stop(handle);
if (ret2)
@@ -3760,42 +3757,39 @@ int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
ssize_t len)
{
handle_t *handle;
- ext4_lblk_t block;
unsigned int max_blocks;
int ret = 0;
int ret2 = 0;
- struct buffer_head map_bh;
+ struct ext4_map_blocks map;
unsigned int credits, blkbits = inode->i_blkbits;
- block = offset >> blkbits;
+ map.m_lblk = offset >> blkbits;
/*
* We can't just convert len to max_blocks because
* If blocksize = 4096 offset = 3072 and len = 2048
*/
- max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
- - block;
+ max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) -
+ map.m_lblk);
/*
* credits to insert 1 extent into extent tree
*/
credits = ext4_chunk_trans_blocks(inode, max_blocks);
while (ret >= 0 && ret < max_blocks) {
- block = block + ret;
- max_blocks = max_blocks - ret;
+ map.m_lblk += ret;
+ map.m_len = (max_blocks -= ret);
handle = ext4_journal_start(inode, credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
break;
}
- map_bh.b_state = 0;
- ret = ext4_get_blocks(handle, inode, block,
- max_blocks, &map_bh,
+ ret = ext4_map_blocks(handle, inode, &map,
EXT4_GET_BLOCKS_IO_CONVERT_EXT);
if (ret <= 0) {
WARN_ON(ret <= 0);
printk(KERN_ERR "%s: ext4_ext_map_blocks "
"returned error inode#%lu, block=%u, "
"max_blocks=%u", __func__,
- inode->i_ino, block, max_blocks);
+ inode->i_ino, map.m_lblk, map.m_len);
}
ext4_mark_inode_dirty(handle, inode);
ret2 = ext4_journal_stop(handle);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 0b79f46..9b4456f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1345,133 +1345,112 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
return retval;
}
-int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
- unsigned int max_blocks, struct buffer_head *bh,
- int flags)
-{
- struct ext4_map_blocks map;
- int ret;
-
- map.m_lblk = block;
- map.m_len = max_blocks;
-
- ret = ext4_map_blocks(handle, inode, &map, flags);
- if (ret < 0)
- return ret;
-
- bh->b_blocknr = map.m_pblk;
- bh->b_size = inode->i_sb->s_blocksize * map.m_len;
- bh->b_bdev = inode->i_sb->s_bdev;
- bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
- return ret;
-}
-
/* Maximum number of blocks we map for direct IO at once. */
#define DIO_MAX_BLOCKS 4096
-int ext4_get_block(struct inode *inode, sector_t iblock,
- struct buffer_head *bh_result, int create)
+static int _ext4_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh, int flags)
{
handle_t *handle = ext4_journal_current_handle();
+ struct ext4_map_blocks map;
int ret = 0, started = 0;
- unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
int dio_credits;
- if (create && !handle) {
+ map.m_lblk = iblock;
+ map.m_len = bh->b_size >> inode->i_blkbits;
+
+ if (flags && !handle) {
/* Direct IO write... */
- if (max_blocks > DIO_MAX_BLOCKS)
- max_blocks = DIO_MAX_BLOCKS;
- dio_credits = ext4_chunk_trans_blocks(inode, max_blocks);
+ if (map.m_len > DIO_MAX_BLOCKS)
+ map.m_len = DIO_MAX_BLOCKS;
+ dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
handle = ext4_journal_start(inode, dio_credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
- goto out;
+ return ret;
}
started = 1;
}
- ret = ext4_get_blocks(handle, inode, iblock, max_blocks, bh_result,
- create ? EXT4_GET_BLOCKS_CREATE : 0);
+ ret = ext4_map_blocks(handle, inode, &map, flags);
if (ret > 0) {
- bh_result->b_size = (ret << inode->i_blkbits);
+ map_bh(bh, inode->i_sb, map.m_pblk);
+ bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
+ bh->b_size = inode->i_sb->s_blocksize * map.m_len;
ret = 0;
}
if (started)
ext4_journal_stop(handle);
-out:
return ret;
}
+int ext4_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh, int create)
+{
+ return _ext4_get_block(inode, iblock, bh,
+ create ? EXT4_GET_BLOCKS_CREATE : 0);
+}
+
/*
* `handle' can be NULL if create is zero
*/
struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
ext4_lblk_t block, int create, int *errp)
{
- struct buffer_head dummy;
+ struct ext4_map_blocks map;
+ struct buffer_head *bh;
int fatal = 0, err;
- int flags = 0;
J_ASSERT(handle != NULL || create == 0);
- dummy.b_state = 0;
- dummy.b_blocknr = -1000;
- buffer_trace_init(&dummy.b_history);
- if (create)
- flags |= EXT4_GET_BLOCKS_CREATE;
- err = ext4_get_blocks(handle, inode, block, 1, &dummy, flags);
- /*
- * ext4_get_blocks() returns number of blocks mapped. 0 in
- * case of a HOLE.
- */
- if (err > 0) {
- if (err > 1)
- WARN_ON(1);
- err = 0;
+ map.m_lblk = block;
+ map.m_len = 1;
+ err = ext4_map_blocks(handle, inode, &map,
+ create ? EXT4_GET_BLOCKS_CREATE : 0);
+
+ if (err < 0)
+ *errp = err;
+ if (err <= 0)
+ return NULL;
+ *errp = 0;
+
+ bh = sb_getblk(inode->i_sb, map.m_pblk);
+ if (!bh) {
+ *errp = -EIO;
+ return NULL;
}
- *errp = err;
- if (!err && buffer_mapped(&dummy)) {
- struct buffer_head *bh;
- bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
- if (!bh) {
- *errp = -EIO;
- goto err;
- }
- if (buffer_new(&dummy)) {
- J_ASSERT(create != 0);
- J_ASSERT(handle != NULL);
+ if (map.m_flags & EXT4_MAP_NEW) {
+ J_ASSERT(create != 0);
+ J_ASSERT(handle != NULL);
- /*
- * Now that we do not always journal data, we should
- * keep in mind whether this should always journal the
- * new buffer as metadata. For now, regular file
- * writes use ext4_get_block instead, so it's not a
- * problem.
- */
- lock_buffer(bh);
- BUFFER_TRACE(bh, "call get_create_access");
- fatal = ext4_journal_get_create_access(handle, bh);
- if (!fatal && !buffer_uptodate(bh)) {
- memset(bh->b_data, 0, inode->i_sb->s_blocksize);
- set_buffer_uptodate(bh);
- }
- unlock_buffer(bh);
- BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
- err = ext4_handle_dirty_metadata(handle, inode, bh);
- if (!fatal)
- fatal = err;
- } else {
- BUFFER_TRACE(bh, "not a new buffer");
- }
- if (fatal) {
- *errp = fatal;
- brelse(bh);
- bh = NULL;
+ /*
+ * Now that we do not always journal data, we should
+ * keep in mind whether this should always journal the
+ * new buffer as metadata. For now, regular file
+ * writes use ext4_get_block instead, so it's not a
+ * problem.
+ */
+ lock_buffer(bh);
+ BUFFER_TRACE(bh, "call get_create_access");
+ fatal = ext4_journal_get_create_access(handle, bh);
+ if (!fatal && !buffer_uptodate(bh)) {
+ memset(bh->b_data, 0, inode->i_sb->s_blocksize);
+ set_buffer_uptodate(bh);
}
- return bh;
+ unlock_buffer(bh);
+ BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+ err = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (!fatal)
+ fatal = err;
+ } else {
+ BUFFER_TRACE(bh, "not a new buffer");
}
-err:
- return NULL;
+ if (fatal) {
+ *errp = fatal;
+ brelse(bh);
+ bh = NULL;
+ }
+ return bh;
}
struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
@@ -2056,28 +2035,23 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd)
/*
* mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
*
- * @mpd->inode - inode to walk through
- * @exbh->b_blocknr - first block on a disk
- * @exbh->b_size - amount of space in bytes
- * @logical - first logical block to start assignment with
- *
* the function goes through all passed space and put actual disk
* block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
*/
-static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
- struct buffer_head *exbh)
+static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd,
+ struct ext4_map_blocks *map)
{
struct inode *inode = mpd->inode;
struct address_space *mapping = inode->i_mapping;
- int blocks = exbh->b_size >> inode->i_blkbits;
- sector_t pblock = exbh->b_blocknr, cur_logical;
+ int blocks = map->m_len;
+ sector_t pblock = map->m_pblk, cur_logical;
struct buffer_head *head, *bh;
pgoff_t index, end;
struct pagevec pvec;
int nr_pages, i;
- index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
- end = (logical + blocks - 1) >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ index = map->m_lblk >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ end = (map->m_lblk + blocks - 1) >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
cur_logical = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
pagevec_init(&pvec, 0);
@@ -2104,17 +2078,16 @@ static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
/* skip blocks out of the range */
do {
- if (cur_logical >= logical)
+ if (cur_logical >= map->m_lblk)
break;
cur_logical++;
} while ((bh = bh->b_this_page) != head);
do {
- if (cur_logical >= logical + blocks)
+ if (cur_logical >= map->m_lblk + blocks)
break;
- if (buffer_delay(bh) ||
- buffer_unwritten(bh)) {
+ if (buffer_delay(bh) || buffer_unwritten(bh)) {
BUG_ON(bh->b_bdev != inode->i_sb->s_bdev);
@@ -2133,7 +2106,7 @@ static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
} else if (buffer_mapped(bh))
BUG_ON(bh->b_blocknr != pblock);
- if (buffer_uninit(exbh))
+ if (map->m_flags & EXT4_MAP_UNINIT)
set_buffer_uninit(bh);
cur_logical++;
pblock++;
@@ -2144,21 +2117,6 @@ static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
}
-/*
- * __unmap_underlying_blocks - just a helper function to unmap
- * set of blocks described by @bh
- */
-static inline void __unmap_underlying_blocks(struct inode *inode,
- struct buffer_head *bh)
-{
- struct block_device *bdev = inode->i_sb->s_bdev;
- int blocks, i;
-
- blocks = bh->b_size >> inode->i_blkbits;
- for (i = 0; i < blocks; i++)
- unmap_underlying_metadata(bdev, bh->b_blocknr + i);
-}
-
static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd,
sector_t logical, long blk_cnt)
{
@@ -2220,7 +2178,7 @@ static void ext4_print_free_blocks(struct inode *inode)
static int mpage_da_map_blocks(struct mpage_da_data *mpd)
{
int err, blks, get_blocks_flags;
- struct buffer_head new;
+ struct ext4_map_blocks map;
sector_t next = mpd->b_blocknr;
unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
@@ -2261,15 +2219,15 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd)
* EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
* variables are updated after the blocks have been allocated.
*/
- new.b_state = 0;
+ map.m_lblk = next;
+ map.m_len = max_blocks;
get_blocks_flags = EXT4_GET_BLOCKS_CREATE;
if (ext4_should_dioread_nolock(mpd->inode))
get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
if (mpd->b_state & (1 << BH_Delay))
get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
- blks = ext4_get_blocks(handle, mpd->inode, next, max_blocks,
- &new, get_blocks_flags);
+ blks = ext4_map_blocks(handle, mpd->inode, &map, get_blocks_flags);
if (blks < 0) {
err = blks;
/*
@@ -2311,10 +2269,13 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd)
}
BUG_ON(blks == 0);
- new.b_size = (blks << mpd->inode->i_blkbits);
+ if (map.m_flags & EXT4_MAP_NEW) {
+ struct block_device *bdev = mpd->inode->i_sb->s_bdev;
+ int i;
- if (buffer_new(&new))
- __unmap_underlying_blocks(mpd->inode, &new);
+ for (i = 0; i < map.m_len; i++)
+ unmap_underlying_metadata(bdev, map.m_pblk + i);
+ }
/*
* If blocks are delayed marked, we need to
@@ -2322,7 +2283,7 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd)
*/
if ((mpd->b_state & (1 << BH_Delay)) ||
(mpd->b_state & (1 << BH_Unwritten)))
- mpage_put_bnr_to_bhs(mpd, next, &new);
+ mpage_put_bnr_to_bhs(mpd, &map);
if (ext4_should_order_data(mpd->inode)) {
err = ext4_jbd2_file_inode(handle, mpd->inode);
@@ -2551,8 +2512,9 @@ static int __mpage_da_writepage(struct page *page,
* initialized properly.
*/
static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
- struct buffer_head *bh_result, int create)
+ struct buffer_head *bh, int create)
{
+ struct ext4_map_blocks map;
int ret = 0;
sector_t invalid_block = ~((sector_t) 0xffff);
@@ -2560,45 +2522,50 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
invalid_block = ~0;
BUG_ON(create == 0);
- BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
+ BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
+
+ map.m_lblk = iblock;
+ map.m_len = 1;
/*
* first, we need to know whether the block is allocated already
* preallocated blocks are unmapped but should treated
* the same as allocated blocks.
*/
- ret = ext4_get_blocks(NULL, inode, iblock, 1, bh_result, 0);
- if ((ret == 0) && !buffer_delay(bh_result)) {
- /* the block isn't (pre)allocated yet, let's reserve space */
- /*
- * XXX: __block_prepare_write() unmaps passed block,
- * is it OK?
- */
- ret = ext4_da_reserve_space(inode, iblock);
- if (ret)
- /* not enough space to reserve */
- return ret;
-
- map_bh(bh_result, inode->i_sb, invalid_block);
- set_buffer_new(bh_result);
- set_buffer_delay(bh_result);
- } else if (ret > 0) {
- bh_result->b_size = (ret << inode->i_blkbits);
- if (buffer_unwritten(bh_result)) {
- /* A delayed write to unwritten bh should
- * be marked new and mapped. Mapped ensures
- * that we don't do get_block multiple times
- * when we write to the same offset and new
- * ensures that we do proper zero out for
- * partial write.
+ ret = ext4_map_blocks(NULL, inode, &map, 0);
+ if (ret < 0)
+ return ret;
+ if (ret == 0) {
+ if (!buffer_delay(bh)) {
+ /*
+ * XXX: __block_prepare_write() unmaps passed
+ * block, is it OK?
*/
- set_buffer_new(bh_result);
- set_buffer_mapped(bh_result);
+ ret = ext4_da_reserve_space(inode, iblock);
+ if (ret)
+ return ret; /* not enough space to reserve */
+
+ map_bh(bh, inode->i_sb, invalid_block);
+ set_buffer_new(bh);
+ set_buffer_delay(bh);
}
- ret = 0;
+ return 0;
}
- return ret;
+ map_bh(bh, inode->i_sb, map.m_pblk);
+ bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
+
+ if (buffer_unwritten(bh)) {
+ /* A delayed write to unwritten bh should be marked
+ * new and mapped. Mapped ensures that we don't do
+ * get_block multiple times when we write to the same
+ * offset and new ensures that we do proper zero out
+ * for partial write.
+ */
+ set_buffer_new(bh);
+ set_buffer_mapped(bh);
+ }
+ return 0;
}
/*
@@ -2620,21 +2587,8 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
- int ret = 0;
- unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
-
BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
-
- /*
- * we don't want to do block allocation in writepage
- * so call get_block_wrap with create = 0
- */
- ret = ext4_get_blocks(NULL, inode, iblock, max_blocks, bh_result, 0);
- if (ret > 0) {
- bh_result->b_size = (ret << inode->i_blkbits);
- ret = 0;
- }
- return ret;
+ return _ext4_get_block(inode, iblock, bh_result, 0);
}
static int bget_one(handle_t *handle, struct buffer_head *bh)
@@ -3569,46 +3523,18 @@ out:
return ret;
}
+/*
+ * ext4_get_block used when preparing for a DIO write or buffer write.
+ * We allocate an uinitialized extent if blocks haven't been allocated.
+ * The extent will be converted to initialized after the IO is complete.
+ */
static int ext4_get_block_write(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
- handle_t *handle = ext4_journal_current_handle();
- int ret = 0;
- unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
- int dio_credits;
- int started = 0;
-
ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
inode->i_ino, create);
- /*
- * ext4_get_block in prepare for a DIO write or buffer write.
- * We allocate an uinitialized extent if blocks haven't been allocated.
- * The extent will be converted to initialized after IO complete.
- */
- create = EXT4_GET_BLOCKS_IO_CREATE_EXT;
-
- if (!handle) {
- if (max_blocks > DIO_MAX_BLOCKS)
- max_blocks = DIO_MAX_BLOCKS;
- dio_credits = ext4_chunk_trans_blocks(inode, max_blocks);
- handle = ext4_journal_start(inode, dio_credits);
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- goto out;
- }
- started = 1;
- }
-
- ret = ext4_get_blocks(handle, inode, iblock, max_blocks, bh_result,
- create);
- if (ret > 0) {
- bh_result->b_size = (ret << inode->i_blkbits);
- ret = 0;
- }
- if (started)
- ext4_journal_stop(handle);
-out:
- return ret;
+ return _ext4_get_block(inode, iblock, bh_result,
+ EXT4_GET_BLOCKS_IO_CREATE_EXT);
}
static void dump_completed_IO(struct inode * inode)
--
1.6.6.1.1.g974db.dirty
--
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