mirror of
git://git.yoctoproject.org/linux-yocto.git
synced 2025-07-11 16:25:21 +02:00
btrfs: Factor out write portion of btrfs_get_blocks_direct
Now that the read side is extracted into its own function, do the same to the write side. This leaves btrfs_get_blocks_direct_write with the sole purpose of handling common locking required. Also flip the condition in btrfs_get_blocks_direct_write so that the write case comes first and we check for if (Create) rather than if (!create). This is purely subjective but I believe makes reading a bit more "linear". No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Nikolay Borisov
David Sterba
parent
1c8d0175df
commit
c5794e5178
207
fs/btrfs/inode.c
207
fs/btrfs/inode.c
|
|
@ -7561,6 +7561,104 @@ static int btrfs_get_blocks_direct_read(struct extent_map *em,
|
||||||
return 0;
|
return 0;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
static int btrfs_get_blocks_direct_write(struct extent_map **map,
|
||||||
|
struct buffer_head *bh_result,
|
||||||
|
struct inode *inode,
|
||||||
|
struct btrfs_dio_data *dio_data,
|
||||||
|
u64 start, u64 len)
|
||||||
|
{
|
||||||
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
||||||
|
struct extent_map *em = *map;
|
||||||
|
int ret = 0;
|
||||||
|
|
||||||
|
/*
|
||||||
|
* We don't allocate a new extent in the following cases
|
||||||
|
*
|
||||||
|
* 1) The inode is marked as NODATACOW. In this case we'll just use the
|
||||||
|
* existing extent.
|
||||||
|
* 2) The extent is marked as PREALLOC. We're good to go here and can
|
||||||
|
* just use the extent.
|
||||||
|
*
|
||||||
|
*/
|
||||||
|
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
|
||||||
|
((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
|
||||||
|
em->block_start != EXTENT_MAP_HOLE)) {
|
||||||
|
int type;
|
||||||
|
u64 block_start, orig_start, orig_block_len, ram_bytes;
|
||||||
|
|
||||||
|
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
|
||||||
|
type = BTRFS_ORDERED_PREALLOC;
|
||||||
|
else
|
||||||
|
type = BTRFS_ORDERED_NOCOW;
|
||||||
|
len = min(len, em->len - (start - em->start));
|
||||||
|
block_start = em->block_start + (start - em->start);
|
||||||
|
|
||||||
|
if (can_nocow_extent(inode, start, &len, &orig_start,
|
||||||
|
&orig_block_len, &ram_bytes) == 1 &&
|
||||||
|
btrfs_inc_nocow_writers(fs_info, block_start)) {
|
||||||
|
struct extent_map *em2;
|
||||||
|
|
||||||
|
em2 = btrfs_create_dio_extent(inode, start, len,
|
||||||
|
orig_start, block_start,
|
||||||
|
len, orig_block_len,
|
||||||
|
ram_bytes, type);
|
||||||
|
btrfs_dec_nocow_writers(fs_info, block_start);
|
||||||
|
if (type == BTRFS_ORDERED_PREALLOC) {
|
||||||
|
free_extent_map(em);
|
||||||
|
*map = em = em2;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (em2 && IS_ERR(em2)) {
|
||||||
|
ret = PTR_ERR(em2);
|
||||||
|
goto out;
|
||||||
|
}
|
||||||
|
/*
|
||||||
|
* For inode marked NODATACOW or extent marked PREALLOC,
|
||||||
|
* use the existing or preallocated extent, so does not
|
||||||
|
* need to adjust btrfs_space_info's bytes_may_use.
|
||||||
|
*/
|
||||||
|
btrfs_free_reserved_data_space_noquota(inode, start,
|
||||||
|
len);
|
||||||
|
goto skip_cow;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
/* this will cow the extent */
|
||||||
|
len = bh_result->b_size;
|
||||||
|
free_extent_map(em);
|
||||||
|
*map = em = btrfs_new_extent_direct(inode, start, len);
|
||||||
|
if (IS_ERR(em)) {
|
||||||
|
ret = PTR_ERR(em);
|
||||||
|
goto out;
|
||||||
|
}
|
||||||
|
|
||||||
|
len = min(len, em->len - (start - em->start));
|
||||||
|
|
||||||
|
skip_cow:
|
||||||
|
bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
|
||||||
|
inode->i_blkbits;
|
||||||
|
bh_result->b_size = len;
|
||||||
|
bh_result->b_bdev = em->bdev;
|
||||||
|
set_buffer_mapped(bh_result);
|
||||||
|
|
||||||
|
if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
|
||||||
|
set_buffer_new(bh_result);
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Need to update the i_size under the extent lock so buffered
|
||||||
|
* readers will get the updated i_size when we unlock.
|
||||||
|
*/
|
||||||
|
if (!dio_data->overwrite && start + len > i_size_read(inode))
|
||||||
|
i_size_write(inode, start + len);
|
||||||
|
|
||||||
|
WARN_ON(dio_data->reserve < len);
|
||||||
|
dio_data->reserve -= len;
|
||||||
|
dio_data->unsubmitted_oe_range_end = start + len;
|
||||||
|
current->journal_info = dio_data;
|
||||||
|
out:
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
||||||
static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
|
static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
|
||||||
struct buffer_head *bh_result, int create)
|
struct buffer_head *bh_result, int create)
|
||||||
{
|
{
|
||||||
|
|
@ -7629,7 +7727,16 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
|
||||||
goto unlock_err;
|
goto unlock_err;
|
||||||
}
|
}
|
||||||
|
|
||||||
if (!create) {
|
if (create) {
|
||||||
|
ret = btrfs_get_blocks_direct_write(&em, bh_result, inode,
|
||||||
|
dio_data, start, len);
|
||||||
|
if (ret < 0)
|
||||||
|
goto unlock_err;
|
||||||
|
|
||||||
|
/* clear and unlock the entire range */
|
||||||
|
clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
|
||||||
|
unlock_bits, 1, 0, &cached_state);
|
||||||
|
} else {
|
||||||
ret = btrfs_get_blocks_direct_read(em, bh_result, inode,
|
ret = btrfs_get_blocks_direct_read(em, bh_result, inode,
|
||||||
start, len);
|
start, len);
|
||||||
/* Can be negative only if we read from a hole */
|
/* Can be negative only if we read from a hole */
|
||||||
|
|
@ -7650,106 +7757,8 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
|
||||||
} else {
|
} else {
|
||||||
free_extent_state(cached_state);
|
free_extent_state(cached_state);
|
||||||
}
|
}
|
||||||
free_extent_map(em);
|
|
||||||
return 0;
|
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
|
||||||
* We don't allocate a new extent in the following cases
|
|
||||||
*
|
|
||||||
* 1) The inode is marked as NODATACOW. In this case we'll just use the
|
|
||||||
* existing extent.
|
|
||||||
* 2) The extent is marked as PREALLOC. We're good to go here and can
|
|
||||||
* just use the extent.
|
|
||||||
*
|
|
||||||
*/
|
|
||||||
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
|
|
||||||
((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
|
|
||||||
em->block_start != EXTENT_MAP_HOLE)) {
|
|
||||||
int type;
|
|
||||||
u64 block_start, orig_start, orig_block_len, ram_bytes;
|
|
||||||
|
|
||||||
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
|
|
||||||
type = BTRFS_ORDERED_PREALLOC;
|
|
||||||
else
|
|
||||||
type = BTRFS_ORDERED_NOCOW;
|
|
||||||
len = min(len, em->len - (start - em->start));
|
|
||||||
block_start = em->block_start + (start - em->start);
|
|
||||||
|
|
||||||
if (can_nocow_extent(inode, start, &len, &orig_start,
|
|
||||||
&orig_block_len, &ram_bytes) == 1 &&
|
|
||||||
btrfs_inc_nocow_writers(fs_info, block_start)) {
|
|
||||||
struct extent_map *em2;
|
|
||||||
|
|
||||||
em2 = btrfs_create_dio_extent(inode, start, len,
|
|
||||||
orig_start, block_start,
|
|
||||||
len, orig_block_len,
|
|
||||||
ram_bytes, type);
|
|
||||||
btrfs_dec_nocow_writers(fs_info, block_start);
|
|
||||||
if (type == BTRFS_ORDERED_PREALLOC) {
|
|
||||||
free_extent_map(em);
|
|
||||||
em = em2;
|
|
||||||
}
|
|
||||||
if (em2 && IS_ERR(em2)) {
|
|
||||||
ret = PTR_ERR(em2);
|
|
||||||
goto unlock_err;
|
|
||||||
}
|
|
||||||
/*
|
|
||||||
* For inode marked NODATACOW or extent marked PREALLOC,
|
|
||||||
* use the existing or preallocated extent, so does not
|
|
||||||
* need to adjust btrfs_space_info's bytes_may_use.
|
|
||||||
*/
|
|
||||||
btrfs_free_reserved_data_space_noquota(inode,
|
|
||||||
start, len);
|
|
||||||
goto unlock;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
|
||||||
* this will cow the extent, reset the len in case we changed
|
|
||||||
* it above
|
|
||||||
*/
|
|
||||||
len = bh_result->b_size;
|
|
||||||
free_extent_map(em);
|
|
||||||
em = btrfs_new_extent_direct(inode, start, len);
|
|
||||||
if (IS_ERR(em)) {
|
|
||||||
ret = PTR_ERR(em);
|
|
||||||
goto unlock_err;
|
|
||||||
}
|
|
||||||
len = min(len, em->len - (start - em->start));
|
|
||||||
unlock:
|
|
||||||
bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
|
|
||||||
inode->i_blkbits;
|
|
||||||
bh_result->b_size = len;
|
|
||||||
bh_result->b_bdev = em->bdev;
|
|
||||||
set_buffer_mapped(bh_result);
|
|
||||||
if (create) {
|
|
||||||
if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
|
|
||||||
set_buffer_new(bh_result);
|
|
||||||
|
|
||||||
/*
|
|
||||||
* Need to update the i_size under the extent lock so buffered
|
|
||||||
* readers will get the updated i_size when we unlock.
|
|
||||||
*/
|
|
||||||
if (!dio_data->overwrite && start + len > i_size_read(inode))
|
|
||||||
i_size_write(inode, start + len);
|
|
||||||
|
|
||||||
WARN_ON(dio_data->reserve < len);
|
|
||||||
dio_data->reserve -= len;
|
|
||||||
dio_data->unsubmitted_oe_range_end = start + len;
|
|
||||||
current->journal_info = dio_data;
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
|
||||||
* In the case of write we need to clear and unlock the entire range,
|
|
||||||
* in the case of read we need to unlock only the end area that we
|
|
||||||
* aren't using if there is any left over space.
|
|
||||||
*/
|
|
||||||
if (lockstart < lockend) {
|
|
||||||
clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
|
|
||||||
lockend, unlock_bits, 1, 0,
|
|
||||||
&cached_state);
|
|
||||||
}
|
|
||||||
free_extent_map(em);
|
free_extent_map(em);
|
||||||
|
|
||||||
return 0;
|
return 0;
|
||||||
|
|
|
||||||
Loading…
Reference in New Issue
Block a user