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ext4: Add new abstraction ext4_map_blocks() underneath ext4_get_blocks()

Browse Source 
Jack up ext4_get_blocks() and add a new function, ext4_map_blocks()
which uses a much smaller structure, struct ext4_map_blocks which is
20 bytes, as opposed to a struct buffer_head, which nearly 5 times
bigger on an x86_64 machine.  By switching things to use
ext4_map_blocks(), we can save stack space by using ext4_map_blocks()
since we can avoid allocating a struct buffer_head on the stack.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o 2010-05-16 19:00:00 -04:00
parent 8e48dcfbd7
commit e35fd6609b
3 changed files with 199 additions and 170 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
fs/ext4/ext4.h
View File

@ -125,6 +125,29 @@ struct ext4_allocation_request {
unsigned int flags;
};
/*
* Logical to physical block mapping, used by ext4_map_blocks()
*
* This structure is used to pass requests into ext4_map_blocks() as
* well as to store the information returned by ext4_map_blocks(). It
* takes less room on the stack than a struct buffer_head.
*/
#define EXT4_MAP_NEW (1 << BH_New)
#define EXT4_MAP_MAPPED (1 << BH_Mapped)
#define EXT4_MAP_UNWRITTEN (1 << BH_Unwritten)
#define EXT4_MAP_BOUNDARY (1 << BH_Boundary)
#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)
struct ext4_map_blocks {
ext4_fsblk_t m_pblk;
ext4_lblk_t m_lblk;
unsigned int m_len;
unsigned int m_flags;
};
/*
* For delayed allocation tracking
*/
@ -1773,9 +1796,8 @@ extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
int chunk);
extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
ext4_lblk_t iblock, unsigned int max_blocks,
struct buffer_head *bh_result, int flags);
extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
struct ext4_map_blocks *map, int flags);
extern void ext4_ext_truncate(struct inode *);
extern void ext4_ext_init(struct super_block *);
extern void ext4_ext_release(struct super_block *);
@ -1783,6 +1805,8 @@ extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
loff_t len);
extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
ssize_t len);
extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
struct ext4_map_blocks *map, int flags);
extern int ext4_get_blocks(handle_t *handle, struct inode *inode,
sector_t block, unsigned int max_blocks,
struct buffer_head *bh, int flags);

237
fs/ext4/extents.c
View File

@ -2611,7 +2611,7 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
#define EXT4_EXT_ZERO_LEN 7
/*
* This function is called by ext4_ext_get_blocks() if someone tries to write
* This function is called by ext4_ext_map_blocks() if someone tries to write
* to an uninitialized extent. It may result in splitting the uninitialized
* extent into multiple extents (upto three - one initialized and two
* uninitialized).
@ -2621,10 +2621,9 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
* c> Splits in three extents: Somone is writing in middle of the extent
*/
static int ext4_ext_convert_to_initialized(handle_t *handle,
struct inode *inode,
struct ext4_ext_path *path,
ext4_lblk_t iblock,
unsigned int max_blocks)
struct inode *inode,
struct ext4_map_blocks *map,
struct ext4_ext_path *path)
{
struct ext4_extent *ex, newex, orig_ex;
struct ext4_extent *ex1 = NULL;
@ -2640,20 +2639,20 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
"block %llu, max_blocks %u\n", inode->i_ino,
(unsigned long long)iblock, max_blocks);
(unsigned long long)map->m_lblk, map->m_len);
eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
inode->i_sb->s_blocksize_bits;
if (eof_block < iblock + max_blocks)
eof_block = iblock + max_blocks;
if (eof_block < map->m_lblk + map->m_len)
eof_block = map->m_lblk + map->m_len;
depth = ext_depth(inode);
eh = path[depth].p_hdr;
ex = path[depth].p_ext;
ee_block = le32_to_cpu(ex->ee_block);
ee_len = ext4_ext_get_actual_len(ex);
allocated = ee_len - (iblock - ee_block);
newblock = iblock - ee_block + ext_pblock(ex);
allocated = ee_len - (map->m_lblk - ee_block);
newblock = map->m_lblk - ee_block + ext_pblock(ex);
ex2 = ex;
orig_ex.ee_block = ex->ee_block;
@ -2683,10 +2682,10 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
return allocated;
}
/* ex1: ee_block to iblock - 1 : uninitialized */
if (iblock > ee_block) {
/* ex1: ee_block to map->m_lblk - 1 : uninitialized */
if (map->m_lblk > ee_block) {
ex1 = ex;
ex1->ee_len = cpu_to_le16(iblock - ee_block);
ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block);
ext4_ext_mark_uninitialized(ex1);
ex2 = &newex;
}
@ -2695,15 +2694,15 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
* we insert ex3, if ex1 is NULL. This is to avoid temporary
* overlap of blocks.
*/
if (!ex1 && allocated > max_blocks)
ex2->ee_len = cpu_to_le16(max_blocks);
if (!ex1 && allocated > map->m_len)
ex2->ee_len = cpu_to_le16(map->m_len);
/* ex3: to ee_block + ee_len : uninitialised */
if (allocated > max_blocks) {
if (allocated > map->m_len) {
unsigned int newdepth;
/* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */
if (allocated <= EXT4_EXT_ZERO_LEN && may_zeroout) {
/*
* iblock == ee_block is handled by the zerouout
* map->m_lblk == ee_block is handled by the zerouout
* at the beginning.
* Mark first half uninitialized.
* Mark second half initialized and zero out the
@ -2716,7 +2715,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
ext4_ext_dirty(handle, inode, path + depth);
ex3 = &newex;
ex3->ee_block = cpu_to_le32(iblock);
ex3->ee_block = cpu_to_le32(map->m_lblk);
ext4_ext_store_pblock(ex3, newblock);
ex3->ee_len = cpu_to_le16(allocated);
err = ext4_ext_insert_extent(handle, inode, path,
@ -2729,7 +2728,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
ex->ee_len = orig_ex.ee_len;
ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
ext4_ext_dirty(handle, inode, path + depth);
/* blocks available from iblock */
/* blocks available from map->m_lblk */
return allocated;
} else if (err)
@ -2751,8 +2750,8 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
*/
depth = ext_depth(inode);
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode,
iblock, path);
path = ext4_ext_find_extent(inode, map->m_lblk,
path);
if (IS_ERR(path)) {
err = PTR_ERR(path);
return err;
@ -2772,9 +2771,9 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
return allocated;
}
ex3 = &newex;
ex3->ee_block = cpu_to_le32(iblock + max_blocks);
ext4_ext_store_pblock(ex3, newblock + max_blocks);
ex3->ee_len = cpu_to_le16(allocated - max_blocks);
ex3->ee_block = cpu_to_le32(map->m_lblk + map->m_len);
ext4_ext_store_pblock(ex3, newblock + map->m_len);
ex3->ee_len = cpu_to_le16(allocated - map->m_len);
ext4_ext_mark_uninitialized(ex3);
err = ext4_ext_insert_extent(handle, inode, path, ex3, 0);
if (err == -ENOSPC && may_zeroout) {
@ -2787,7 +2786,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
ext4_ext_dirty(handle, inode, path + depth);
/* zeroed the full extent */
/* blocks available from iblock */
/* blocks available from map->m_lblk */
return allocated;
} else if (err)
@ -2807,7 +2806,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
depth = newdepth;
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode, iblock, path);
path = ext4_ext_find_extent(inode, map->m_lblk, path);
if (IS_ERR(path)) {
err = PTR_ERR(path);
goto out;
@ -2821,14 +2820,14 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
if (err)
goto out;
allocated = max_blocks;
allocated = map->m_len;
/* If extent has less than EXT4_EXT_ZERO_LEN and we are trying
* to insert a extent in the middle zerout directly
* otherwise give the extent a chance to merge to left
*/
if (le16_to_cpu(orig_ex.ee_len) <= EXT4_EXT_ZERO_LEN &&
iblock != ee_block && may_zeroout) {
map->m_lblk != ee_block && may_zeroout) {
err = ext4_ext_zeroout(inode, &orig_ex);
if (err)
goto fix_extent_len;
@ -2838,7 +2837,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
ext4_ext_dirty(handle, inode, path + depth);
/* zero out the first half */
/* blocks available from iblock */
/* blocks available from map->m_lblk */
return allocated;
}
}
@ -2849,12 +2848,12 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
*/
if (ex1 && ex1 != ex) {
ex1 = ex;
ex1->ee_len = cpu_to_le16(iblock - ee_block);
ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block);
ext4_ext_mark_uninitialized(ex1);
ex2 = &newex;
}
/* ex2: iblock to iblock + maxblocks-1 : initialised */
ex2->ee_block = cpu_to_le32(iblock);
/* ex2: map->m_lblk to map->m_lblk + maxblocks-1 : initialised */
ex2->ee_block = cpu_to_le32(map->m_lblk);
ext4_ext_store_pblock(ex2, newblock);
ex2->ee_len = cpu_to_le16(allocated);
if (ex2 != ex)
@ -2924,7 +2923,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
}
/*
* This function is called by ext4_ext_get_blocks() from
* This function is called by ext4_ext_map_blocks() from
* ext4_get_blocks_dio_write() when DIO to write
* to an uninitialized extent.
*
@ -2947,9 +2946,8 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
*/
static int ext4_split_unwritten_extents(handle_t *handle,
struct inode *inode,
struct ext4_map_blocks *map,
struct ext4_ext_path *path,
ext4_lblk_t iblock,
unsigned int max_blocks,
int flags)
{
struct ext4_extent *ex, newex, orig_ex;
@ -2965,20 +2963,20 @@ static int ext4_split_unwritten_extents(handle_t *handle,
ext_debug("ext4_split_unwritten_extents: inode %lu, logical"
"block %llu, max_blocks %u\n", inode->i_ino,
(unsigned long long)iblock, max_blocks);
(unsigned long long)map->m_lblk, map->m_len);
eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
inode->i_sb->s_blocksize_bits;
if (eof_block < iblock + max_blocks)
eof_block = iblock + max_blocks;
if (eof_block < map->m_lblk + map->m_len)
eof_block = map->m_lblk + map->m_len;
depth = ext_depth(inode);
eh = path[depth].p_hdr;
ex = path[depth].p_ext;
ee_block = le32_to_cpu(ex->ee_block);
ee_len = ext4_ext_get_actual_len(ex);
allocated = ee_len - (iblock - ee_block);
newblock = iblock - ee_block + ext_pblock(ex);
allocated = ee_len - (map->m_lblk - ee_block);
newblock = map->m_lblk - ee_block + ext_pblock(ex);
ex2 = ex;
orig_ex.ee_block = ex->ee_block;
@ -2996,16 +2994,16 @@ static int ext4_split_unwritten_extents(handle_t *handle,
* block where the write begins, and the write completely
* covers the extent, then we don't need to split it.
*/
if ((iblock == ee_block) && (allocated <= max_blocks))
if ((map->m_lblk == ee_block) && (allocated <= map->m_len))
return allocated;
err = ext4_ext_get_access(handle, inode, path + depth);
if (err)
goto out;
/* ex1: ee_block to iblock - 1 : uninitialized */
if (iblock > ee_block) {
/* ex1: ee_block to map->m_lblk - 1 : uninitialized */
if (map->m_lblk > ee_block) {
ex1 = ex;
ex1->ee_len = cpu_to_le16(iblock - ee_block);
ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block);
ext4_ext_mark_uninitialized(ex1);
ex2 = &newex;
}
@ -3014,15 +3012,15 @@ static int ext4_split_unwritten_extents(handle_t *handle,
* we insert ex3, if ex1 is NULL. This is to avoid temporary
* overlap of blocks.
*/
if (!ex1 && allocated > max_blocks)
ex2->ee_len = cpu_to_le16(max_blocks);
if (!ex1 && allocated > map->m_len)
ex2->ee_len = cpu_to_le16(map->m_len);
/* ex3: to ee_block + ee_len : uninitialised */
if (allocated > max_blocks) {
if (allocated > map->m_len) {
unsigned int newdepth;
ex3 = &newex;
ex3->ee_block = cpu_to_le32(iblock + max_blocks);
ext4_ext_store_pblock(ex3, newblock + max_blocks);
ex3->ee_len = cpu_to_le16(allocated - max_blocks);
ex3->ee_block = cpu_to_le32(map->m_lblk + map->m_len);
ext4_ext_store_pblock(ex3, newblock + map->m_len);
ex3->ee_len = cpu_to_le16(allocated - map->m_len);
ext4_ext_mark_uninitialized(ex3);
err = ext4_ext_insert_extent(handle, inode, path, ex3, flags);
if (err == -ENOSPC && may_zeroout) {
@ -3035,7 +3033,7 @@ static int ext4_split_unwritten_extents(handle_t *handle,
ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
ext4_ext_dirty(handle, inode, path + depth);
/* zeroed the full extent */
/* blocks available from iblock */
/* blocks available from map->m_lblk */
return allocated;
} else if (err)
@ -3055,7 +3053,7 @@ static int ext4_split_unwritten_extents(handle_t *handle,
depth = newdepth;
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode, iblock, path);
path = ext4_ext_find_extent(inode, map->m_lblk, path);
if (IS_ERR(path)) {
err = PTR_ERR(path);
goto out;
@ -3069,7 +3067,7 @@ static int ext4_split_unwritten_extents(handle_t *handle,
if (err)
goto out;
allocated = max_blocks;
allocated = map->m_len;
}
/*
* If there was a change of depth as part of the
@ -3078,15 +3076,15 @@ static int ext4_split_unwritten_extents(handle_t *handle,
*/
if (ex1 && ex1 != ex) {
ex1 = ex;
ex1->ee_len = cpu_to_le16(iblock - ee_block);
ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block);
ext4_ext_mark_uninitialized(ex1);
ex2 = &newex;
}
/*
* ex2: iblock to iblock + maxblocks-1 : to be direct IO written,
* uninitialised still.
* ex2: map->m_lblk to map->m_lblk + map->m_len-1 : to be written
* using direct I/O, uninitialised still.
*/
ex2->ee_block = cpu_to_le32(iblock);
ex2->ee_block = cpu_to_le32(map->m_lblk);
ext4_ext_store_pblock(ex2, newblock);
ex2->ee_len = cpu_to_le16(allocated);
ext4_ext_mark_uninitialized(ex2);
@ -3188,10 +3186,9 @@ static void unmap_underlying_metadata_blocks(struct block_device *bdev,
static int
ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
ext4_lblk_t iblock, unsigned int max_blocks,
struct ext4_map_blocks *map,
struct ext4_ext_path *path, int flags,
unsigned int allocated, struct buffer_head *bh_result,
ext4_fsblk_t newblock)
unsigned int allocated, ext4_fsblk_t newblock)
{
int ret = 0;
int err = 0;
@ -3199,15 +3196,14 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical"
"block %llu, max_blocks %u, flags %d, allocated %u",
inode->i_ino, (unsigned long long)iblock, max_blocks,
inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
flags, allocated);
ext4_ext_show_leaf(inode, path);
/* get_block() before submit the IO, split the extent */
if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
ret = ext4_split_unwritten_extents(handle,
inode, path, iblock,
max_blocks, flags);
ret = ext4_split_unwritten_extents(handle, inode, map,
path, flags);
/*
* Flag the inode(non aio case) or end_io struct (aio case)
* that this IO needs to convertion to written when IO is
@ -3218,7 +3214,7 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
else
ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
if (ext4_should_dioread_nolock(inode))
set_buffer_uninit(bh_result);
map->m_flags |= EXT4_MAP_UNINIT;
goto out;
}
/* IO end_io complete, convert the filled extent to written */
@ -3246,14 +3242,12 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
* the buffer head will be unmapped so that
* a read from the block returns 0s.
*/
set_buffer_unwritten(bh_result);
map->m_flags |= EXT4_MAP_UNWRITTEN;
goto out1;
}
/* buffered write, writepage time, convert*/
ret = ext4_ext_convert_to_initialized(handle, inode,
path, iblock,
max_blocks);
ret = ext4_ext_convert_to_initialized(handle, inode, map, path);
if (ret >= 0)
ext4_update_inode_fsync_trans(handle, inode, 1);
out:
@ -3262,7 +3256,7 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
goto out2;
} else
allocated = ret;
set_buffer_new(bh_result);
map->m_flags |= EXT4_MAP_NEW;
/*
* if we allocated more blocks than requested
* we need to make sure we unmap the extra block
@ -3270,11 +3264,11 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
* unmapped later when we find the buffer_head marked
* new.
*/
if (allocated > max_blocks) {
if (allocated > map->m_len) {
unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
newblock + max_blocks,
allocated - max_blocks);
allocated = max_blocks;
newblock + map->m_len,
allocated - map->m_len);
allocated = map->m_len;
}
/*
@ -3288,13 +3282,13 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
ext4_da_update_reserve_space(inode, allocated, 0);
map_out:
set_buffer_mapped(bh_result);
map->m_flags |= EXT4_MAP_MAPPED;
out1:
if (allocated > max_blocks)
allocated = max_blocks;
if (allocated > map->m_len)
allocated = map->m_len;
ext4_ext_show_leaf(inode, path);
bh_result->b_bdev = inode->i_sb->s_bdev;
bh_result->b_blocknr = newblock;
map->m_pblk = newblock;
map->m_len = allocated;
out2:
if (path) {
ext4_ext_drop_refs(path);
@ -3320,10 +3314,8 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
*
* return < 0, error case.
*/
int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
ext4_lblk_t iblock,
unsigned int max_blocks, struct buffer_head *bh_result,
int flags)
int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
struct ext4_map_blocks *map, int flags)
{
struct ext4_ext_path *path = NULL;
struct ext4_extent_header *eh;
@ -3334,12 +3326,11 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
struct ext4_allocation_request ar;
ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
__clear_bit(BH_New, &bh_result->b_state);
ext_debug("blocks %u/%u requested for inode %lu\n",
iblock, max_blocks, inode->i_ino);
map->m_lblk, map->m_len, inode->i_ino);
/* check in cache */
cache_type = ext4_ext_in_cache(inode, iblock, &newex);
cache_type = ext4_ext_in_cache(inode, map->m_lblk, &newex);
if (cache_type) {
if (cache_type == EXT4_EXT_CACHE_GAP) {
if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
@ -3352,12 +3343,12 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
/* we should allocate requested block */
} else if (cache_type == EXT4_EXT_CACHE_EXTENT) {
/* block is already allocated */
newblock = iblock
newblock = map->m_lblk
- le32_to_cpu(newex.ee_block)
+ ext_pblock(&newex);
/* number of remaining blocks in the extent */
allocated = ext4_ext_get_actual_len(&newex) -
(iblock - le32_to_cpu(newex.ee_block));
(map->m_lblk - le32_to_cpu(newex.ee_block));
goto out;
} else {
BUG();
@ -3365,7 +3356,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
}
/* find extent for this block */
path = ext4_ext_find_extent(inode, iblock, NULL);
path = ext4_ext_find_extent(inode, map->m_lblk, NULL);
if (IS_ERR(path)) {
err = PTR_ERR(path);
path = NULL;
@ -3382,7 +3373,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
EXT4_ERROR_INODE(inode, "bad extent address "
"iblock: %d, depth: %d pblock %lld",
iblock, depth, path[depth].p_block);
map->m_lblk, depth, path[depth].p_block);
err = -EIO;
goto out2;
}
@ -3400,12 +3391,12 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
*/
ee_len = ext4_ext_get_actual_len(ex);
/* if found extent covers block, simply return it */
if (in_range(iblock, ee_block, ee_len)) {
newblock = iblock - ee_block + ee_start;
if (in_range(map->m_lblk, ee_block, ee_len)) {
newblock = map->m_lblk - ee_block + ee_start;
/* number of remaining blocks in the extent */
allocated = ee_len - (iblock - ee_block);
ext_debug("%u fit into %u:%d -> %llu\n", iblock,
ee_block, ee_len, newblock);
allocated = ee_len - (map->m_lblk - ee_block);
ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
ee_block, ee_len, newblock);
/* Do not put uninitialized extent in the cache */
if (!ext4_ext_is_uninitialized(ex)) {
@ -3415,8 +3406,8 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
goto out;
}
ret = ext4_ext_handle_uninitialized_extents(handle,
inode, iblock, max_blocks, path,
flags, allocated, bh_result, newblock);
inode, map, path, flags, allocated,
newblock);
return ret;
}
}
@ -3430,7 +3421,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
* put just found gap into cache to speed up
* subsequent requests
*/
ext4_ext_put_gap_in_cache(inode, path, iblock);
ext4_ext_put_gap_in_cache(inode, path, map->m_lblk);
goto out2;
}
/*
@ -3438,11 +3429,11 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
*/
/* find neighbour allocated blocks */
ar.lleft = iblock;
ar.lleft = map->m_lblk;
err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
if (err)
goto out2;
ar.lright = iblock;
ar.lright = map->m_lblk;
err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright);
if (err)
goto out2;
@ -3453,26 +3444,26 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
* EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
* EXT_UNINIT_MAX_LEN.
*/
if (max_blocks > EXT_INIT_MAX_LEN &&
if (map->m_len > EXT_INIT_MAX_LEN &&
!(flags & EXT4_GET_BLOCKS_UNINIT_EXT))
max_blocks = EXT_INIT_MAX_LEN;
else if (max_blocks > EXT_UNINIT_MAX_LEN &&
map->m_len = EXT_INIT_MAX_LEN;
else if (map->m_len > EXT_UNINIT_MAX_LEN &&
(flags & EXT4_GET_BLOCKS_UNINIT_EXT))
max_blocks = EXT_UNINIT_MAX_LEN;
map->m_len = EXT_UNINIT_MAX_LEN;
/* Check if we can really insert (iblock)::(iblock+max_blocks) extent */
newex.ee_block = cpu_to_le32(iblock);
newex.ee_len = cpu_to_le16(max_blocks);
/* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
newex.ee_block = cpu_to_le32(map->m_lblk);
newex.ee_len = cpu_to_le16(map->m_len);
err = ext4_ext_check_overlap(inode, &newex, path);
if (err)
allocated = ext4_ext_get_actual_len(&newex);
else
allocated = max_blocks;
allocated = map->m_len;
/* allocate new block */
ar.inode = inode;
ar.goal = ext4_ext_find_goal(inode, path, iblock);
ar.logical = iblock;
ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
ar.logical = map->m_lblk;
ar.len = allocated;
if (S_ISREG(inode->i_mode))
ar.flags = EXT4_MB_HINT_DATA;
@ -3506,7 +3497,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
EXT4_STATE_DIO_UNWRITTEN);
}
if (ext4_should_dioread_nolock(inode))
set_buffer_uninit(bh_result);
map->m_flags |= EXT4_MAP_UNINIT;
}
if (unlikely(EXT4_I(inode)->i_flags & EXT4_EOFBLOCKS_FL)) {
@ -3518,7 +3509,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
goto out2;
}
last_ex = EXT_LAST_EXTENT(eh);
if (iblock + ar.len > le32_to_cpu(last_ex->ee_block)
if (map->m_lblk + ar.len > le32_to_cpu(last_ex->ee_block)
+ ext4_ext_get_actual_len(last_ex))
EXT4_I(inode)->i_flags &= ~EXT4_EOFBLOCKS_FL;
}
@ -3536,9 +3527,9 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
/* previous routine could use block we allocated */
newblock = ext_pblock(&newex);
allocated = ext4_ext_get_actual_len(&newex);
if (allocated > max_blocks)
allocated = max_blocks;
set_buffer_new(bh_result);
if (allocated > map->m_len)
allocated = map->m_len;
map->m_flags |= EXT4_MAP_NEW;
/*
* Update reserved blocks/metadata blocks after successful
@ -3552,18 +3543,18 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
* when it is _not_ an uninitialized extent.
*/
if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) {
ext4_ext_put_in_cache(inode, iblock, allocated, newblock,
ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock,
EXT4_EXT_CACHE_EXTENT);
ext4_update_inode_fsync_trans(handle, inode, 1);
} else
ext4_update_inode_fsync_trans(handle, inode, 0);
out:
if (allocated > max_blocks)
allocated = max_blocks;
if (allocated > map->m_len)
allocated = map->m_len;
ext4_ext_show_leaf(inode, path);
set_buffer_mapped(bh_result);
bh_result->b_bdev = inode->i_sb->s_bdev;
bh_result->b_blocknr = newblock;
map->m_flags |= EXT4_MAP_MAPPED;
map->m_pblk = newblock;
map->m_len = allocated;
out2:
if (path) {
ext4_ext_drop_refs(path);
@ -3729,7 +3720,7 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
if (ret <= 0) {
#ifdef EXT4FS_DEBUG
WARN_ON(ret <= 0);
printk(KERN_ERR "%s: ext4_ext_get_blocks "
printk(KERN_ERR "%s: ext4_ext_map_blocks "
"returned error inode#%lu, block=%u, "
"max_blocks=%u", __func__,
inode->i_ino, block, max_blocks);
@ -3806,7 +3797,7 @@ int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
EXT4_GET_BLOCKS_IO_CONVERT_EXT);
if (ret <= 0) {
WARN_ON(ret <= 0);
printk(KERN_ERR "%s: ext4_ext_get_blocks "
printk(KERN_ERR "%s: ext4_ext_map_blocks "
"returned error inode#%lu, block=%u, "
"max_blocks=%u", __func__,
inode->i_ino, block, max_blocks);

102
fs/ext4/inode.c
View File

@ -149,7 +149,7 @@ int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
int ret;
/*
* Drop i_data_sem to avoid deadlock with ext4_get_blocks At this
* Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
* moment, get_block can be called only for blocks inside i_size since
* page cache has been already dropped and writes are blocked by
* i_mutex. So we can safely drop the i_data_sem here.
@ -890,9 +890,9 @@ static int ext4_splice_branch(handle_t *handle, struct inode *inode,
}
/*
* The ext4_ind_get_blocks() function handles non-extents inodes
* The ext4_ind_map_blocks() function handles non-extents inodes
* (i.e., using the traditional indirect/double-indirect i_blocks
* scheme) for ext4_get_blocks().
* scheme) for ext4_map_blocks().
*
* Allocation strategy is simple: if we have to allocate something, we will
* have to go the whole way to leaf. So let's do it before attaching anything
@ -917,9 +917,8 @@ static int ext4_splice_branch(handle_t *handle, struct inode *inode,
* down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
* blocks.
*/
static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode,
ext4_lblk_t iblock, unsigned int maxblocks,
struct buffer_head *bh_result,
static int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
struct ext4_map_blocks *map,
int flags)
{
int err = -EIO;
@ -935,7 +934,7 @@ static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode,
J_ASSERT(!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL));
J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
depth = ext4_block_to_path(inode, iblock, offsets,
depth = ext4_block_to_path(inode, map->m_lblk, offsets,
&blocks_to_boundary);
if (depth == 0)
@ -946,10 +945,9 @@ static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode,
/* Simplest case - block found, no allocation needed */
if (!partial) {
first_block = le32_to_cpu(chain[depth - 1].key);
clear_buffer_new(bh_result);
count++;
/*map more blocks*/
while (count < maxblocks && count <= blocks_to_boundary) {
while (count < map->m_len && count <= blocks_to_boundary) {
ext4_fsblk_t blk;
blk = le32_to_cpu(*(chain[depth-1].p + count));
@ -969,7 +967,7 @@ static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode,
/*
* Okay, we need to do block allocation.
*/
goal = ext4_find_goal(inode, iblock, partial);
goal = ext4_find_goal(inode, map->m_lblk, partial);
/* the number of blocks need to allocate for [d,t]indirect blocks */
indirect_blks = (chain + depth) - partial - 1;
@ -979,11 +977,11 @@ static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode,
* direct blocks to allocate for this branch.
*/
count = ext4_blks_to_allocate(partial, indirect_blks,
maxblocks, blocks_to_boundary);
map->m_len, blocks_to_boundary);
/*
* Block out ext4_truncate while we alter the tree
*/
err = ext4_alloc_branch(handle, inode, iblock, indirect_blks,
err = ext4_alloc_branch(handle, inode, map->m_lblk, indirect_blks,
&count, goal,
offsets + (partial - chain), partial);
@ -995,18 +993,20 @@ static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode,
* may need to return -EAGAIN upwards in the worst case. --sct
*/
if (!err)
err = ext4_splice_branch(handle, inode, iblock,
err = ext4_splice_branch(handle, inode, map->m_lblk,
partial, indirect_blks, count);
if (err)
goto cleanup;
set_buffer_new(bh_result);
map->m_flags |= EXT4_MAP_NEW;
ext4_update_inode_fsync_trans(handle, inode, 1);
got_it:
map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
map->m_flags |= EXT4_MAP_MAPPED;
map->m_pblk = le32_to_cpu(chain[depth-1].key);
map->m_len = count;
if (count > blocks_to_boundary)
set_buffer_boundary(bh_result);
map->m_flags |= EXT4_MAP_BOUNDARY;
err = count;
/* Clean up and exit */
partial = chain + depth - 1; /* the whole chain */
@ -1016,7 +1016,6 @@ static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode,
brelse(partial->bh);
partial--;
}
BUFFER_TRACE(bh_result, "returned");
out:
return err;
}
@ -1203,15 +1202,15 @@ static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
}
/*
* The ext4_get_blocks() function tries to look up the requested blocks,
* The ext4_map_blocks() function tries to look up the requested blocks,
* and returns if the blocks are already mapped.
*
* Otherwise it takes the write lock of the i_data_sem and allocate blocks
* and store the allocated blocks in the result buffer head and mark it
* mapped.
*
* If file type is extents based, it will call ext4_ext_get_blocks(),
* Otherwise, call with ext4_ind_get_blocks() to handle indirect mapping
* If file type is extents based, it will call ext4_ext_map_blocks(),
* Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
* based files
*
* On success, it returns the number of blocks being mapped or allocate.
@ -1224,35 +1223,30 @@ static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
*
* It returns the error in case of allocation failure.
*/
int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
unsigned int max_blocks, struct buffer_head *bh,
int flags)
int ext4_map_blocks(handle_t *handle, struct inode *inode,
struct ext4_map_blocks *map, int flags)
{
int retval;
clear_buffer_mapped(bh);
clear_buffer_unwritten(bh);
ext_debug("ext4_get_blocks(): inode %lu, flag %d, max_blocks %u,"
"logical block %lu\n", inode->i_ino, flags, max_blocks,
(unsigned long)block);
map->m_flags = 0;
ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
"logical block %lu\n", inode->i_ino, flags, map->m_len,
(unsigned long) map->m_lblk);
/*
* Try to see if we can get the block without requesting a new
* file system block.
*/
down_read((&EXT4_I(inode)->i_data_sem));
if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
retval = ext4_ext_get_blocks(handle, inode, block, max_blocks,
bh, 0);
retval = ext4_ext_map_blocks(handle, inode, map, 0);
} else {
retval = ext4_ind_get_blocks(handle, inode, block, max_blocks,
bh, 0);
retval = ext4_ind_map_blocks(handle, inode, map, 0);
}
up_read((&EXT4_I(inode)->i_data_sem));
if (retval > 0 && buffer_mapped(bh)) {
if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
int ret = check_block_validity(inode, "file system corruption",
block, bh->b_blocknr, retval);
map->m_lblk, map->m_pblk, retval);
if (ret != 0)
return ret;
}
@ -1268,7 +1262,7 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
* ext4_ext_get_block() returns th create = 0
* with buffer head unmapped.
*/
if (retval > 0 && buffer_mapped(bh))
if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
return retval;
/*
@ -1281,7 +1275,7 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
* of BH_Unwritten and BH_Mapped flags being simultaneously
* set on the buffer_head.
*/
clear_buffer_unwritten(bh);
map->m_flags &= ~EXT4_MAP_UNWRITTEN;
/*
* New blocks allocate and/or writing to uninitialized extent
@ -1304,13 +1298,11 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
* could have changed the inode type in between
*/
if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
retval = ext4_ext_get_blocks(handle, inode, block, max_blocks,
bh, flags);
retval = ext4_ext_map_blocks(handle, inode, map, flags);
} else {
retval = ext4_ind_get_blocks(handle, inode, block,
max_blocks, bh, flags);
retval = ext4_ind_map_blocks(handle, inode, map, flags);
if (retval > 0 && buffer_new(bh)) {
if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
/*
* We allocated new blocks which will result in
* i_data's format changing. Force the migrate
@ -1333,16 +1325,38 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
EXT4_I(inode)->i_delalloc_reserved_flag = 0;
up_write((&EXT4_I(inode)->i_data_sem));
if (retval > 0 && buffer_mapped(bh)) {
if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
int ret = check_block_validity(inode, "file system "
"corruption after allocation",
block, bh->b_blocknr, retval);
map->m_lblk, map->m_pblk,
retval);
if (ret != 0)
return ret;
}
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