ext4: fix punch hole on files with indirect mapping
Currently punch hole code on files with direct/indirect mapping has some problems which may lead to a data loss. For example (from Jan Kara): fallocate -n -p 10240000 4096 will punch the range 10240000 - 12632064 instead of the range 1024000 - 10244096. Also the code is a bit weird and it's not using infrastructure provided by indirect.c, but rather creating it's own way. This patch fixes the issues as well as making the operation to run 4 times faster from my testing (punching out 60GB file). It uses similar approach used in ext4_ind_truncate() which takes advantage of ext4_free_branches() function. Also rename the ext4_free_hole_blocks() to something more sensible, like the equivalent we have for extent mapped files. Call it ext4_ind_remove_space(). This has been tested mostly with fsx and some xfstests which are testing punch hole but does not require unwritten extents which are not supported with direct/indirect mapping. Not problems showed up even with 1024k block size. CC: stable@vger.kernel.org Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Lukas Czerner
Theodore Ts'o
Родитель
71d4f7d032
Коммит
4f579ae7de
|
|
@ -2143,8 +2143,8 @@ extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
|
|||
extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
|
||||
extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
|
||||
extern void ext4_ind_truncate(handle_t *, struct inode *inode);
|
||||
extern int ext4_free_hole_blocks(handle_t *handle, struct inode *inode,
|
||||
ext4_lblk_t first, ext4_lblk_t stop);
|
||||
extern int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
|
||||
ext4_lblk_t start, ext4_lblk_t end);
|
||||
|
||||
/* ioctl.c */
|
||||
extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
|
||||
|
|
|
|||
|
|
@ -1295,97 +1295,220 @@ do_indirects:
|
|||
}
|
||||
}
|
||||
|
||||
static int free_hole_blocks(handle_t *handle, struct inode *inode,
|
||||
struct buffer_head *parent_bh, __le32 *i_data,
|
||||
int level, ext4_lblk_t first,
|
||||
ext4_lblk_t count, int max)
|
||||
/**
|
||||
* ext4_ind_remove_space - remove space from the range
|
||||
* @handle: JBD handle for this transaction
|
||||
* @inode: inode we are dealing with
|
||||
* @start: First block to remove
|
||||
* @end: One block after the last block to remove (exclusive)
|
||||
*
|
||||
* Free the blocks in the defined range (end is exclusive endpoint of
|
||||
* range). This is used by ext4_punch_hole().
|
||||
*/
|
||||
int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
|
||||
ext4_lblk_t start, ext4_lblk_t end)
|
||||
{
|
||||
struct buffer_head *bh = NULL;
|
||||
struct ext4_inode_info *ei = EXT4_I(inode);
|
||||
__le32 *i_data = ei->i_data;
|
||||
int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
|
||||
int ret = 0;
|
||||
int i, inc;
|
||||
ext4_lblk_t offset;
|
||||
__le32 blk;
|
||||
ext4_lblk_t offsets[4], offsets2[4];
|
||||
Indirect chain[4], chain2[4];
|
||||
Indirect *partial, *partial2;
|
||||
ext4_lblk_t max_block;
|
||||
__le32 nr = 0, nr2 = 0;
|
||||
int n = 0, n2 = 0;
|
||||
unsigned blocksize = inode->i_sb->s_blocksize;
|
||||
|
||||
inc = 1 << ((EXT4_BLOCK_SIZE_BITS(inode->i_sb) - 2) * level);
|
||||
for (i = 0, offset = 0; i < max; i++, i_data++, offset += inc) {
|
||||
if (offset >= count + first)
|
||||
break;
|
||||
if (*i_data == 0 || (offset + inc) <= first)
|
||||
continue;
|
||||
blk = *i_data;
|
||||
if (level > 0) {
|
||||
ext4_lblk_t first2;
|
||||
ext4_lblk_t count2;
|
||||
max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
|
||||
>> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
|
||||
if (end >= max_block)
|
||||
end = max_block;
|
||||
if ((start >= end) || (start > max_block))
|
||||
return 0;
|
||||
|
||||
bh = sb_bread(inode->i_sb, le32_to_cpu(blk));
|
||||
if (!bh) {
|
||||
EXT4_ERROR_INODE_BLOCK(inode, le32_to_cpu(blk),
|
||||
"Read failure");
|
||||
return -EIO;
|
||||
}
|
||||
if (first > offset) {
|
||||
first2 = first - offset;
|
||||
count2 = count;
|
||||
n = ext4_block_to_path(inode, start, offsets, NULL);
|
||||
n2 = ext4_block_to_path(inode, end, offsets2, NULL);
|
||||
|
||||
BUG_ON(n > n2);
|
||||
|
||||
if ((n == 1) && (n == n2)) {
|
||||
/* We're punching only within direct block range */
|
||||
ext4_free_data(handle, inode, NULL, i_data + offsets[0],
|
||||
i_data + offsets2[0]);
|
||||
return 0;
|
||||
} else if (n2 > n) {
|
||||
/*
|
||||
* Start and end are on a different levels so we're going to
|
||||
* free partial block at start, and partial block at end of
|
||||
* the range. If there are some levels in between then
|
||||
* do_indirects label will take care of that.
|
||||
*/
|
||||
|
||||
if (n == 1) {
|
||||
/*
|
||||
* Start is at the direct block level, free
|
||||
* everything to the end of the level.
|
||||
*/
|
||||
ext4_free_data(handle, inode, NULL, i_data + offsets[0],
|
||||
i_data + EXT4_NDIR_BLOCKS);
|
||||
goto end_range;
|
||||
}
|
||||
|
||||
|
||||
partial = ext4_find_shared(inode, n, offsets, chain, &nr);
|
||||
if (nr) {
|
||||
if (partial == chain) {
|
||||
/* Shared branch grows from the inode */
|
||||
ext4_free_branches(handle, inode, NULL,
|
||||
&nr, &nr+1, (chain+n-1) - partial);
|
||||
*partial->p = 0;
|
||||
} else {
|
||||
first2 = 0;
|
||||
count2 = count - (offset - first);
|
||||
}
|
||||
ret = free_hole_blocks(handle, inode, bh,
|
||||
(__le32 *)bh->b_data, level - 1,
|
||||
first2, count2,
|
||||
inode->i_sb->s_blocksize >> 2);
|
||||
if (ret) {
|
||||
brelse(bh);
|
||||
goto err;
|
||||
/* Shared branch grows from an indirect block */
|
||||
BUFFER_TRACE(partial->bh, "get_write_access");
|
||||
ext4_free_branches(handle, inode, partial->bh,
|
||||
partial->p,
|
||||
partial->p+1, (chain+n-1) - partial);
|
||||
}
|
||||
}
|
||||
if (level == 0 ||
|
||||
(bh && all_zeroes((__le32 *)bh->b_data,
|
||||
(__le32 *)bh->b_data + addr_per_block))) {
|
||||
ext4_free_data(handle, inode, parent_bh,
|
||||
i_data, i_data + 1);
|
||||
|
||||
/*
|
||||
* Clear the ends of indirect blocks on the shared branch
|
||||
* at the start of the range
|
||||
*/
|
||||
while (partial > chain) {
|
||||
ext4_free_branches(handle, inode, partial->bh,
|
||||
partial->p + 1,
|
||||
(__le32 *)partial->bh->b_data+addr_per_block,
|
||||
(chain+n-1) - partial);
|
||||
BUFFER_TRACE(partial->bh, "call brelse");
|
||||
brelse(partial->bh);
|
||||
partial--;
|
||||
}
|
||||
brelse(bh);
|
||||
bh = NULL;
|
||||
}
|
||||
|
||||
err:
|
||||
return ret;
|
||||
}
|
||||
|
||||
int ext4_free_hole_blocks(handle_t *handle, struct inode *inode,
|
||||
ext4_lblk_t first, ext4_lblk_t stop)
|
||||
{
|
||||
int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
|
||||
int level, ret = 0;
|
||||
int num = EXT4_NDIR_BLOCKS;
|
||||
ext4_lblk_t count, max = EXT4_NDIR_BLOCKS;
|
||||
__le32 *i_data = EXT4_I(inode)->i_data;
|
||||
|
||||
count = stop - first;
|
||||
for (level = 0; level < 4; level++, max *= addr_per_block) {
|
||||
if (first < max) {
|
||||
ret = free_hole_blocks(handle, inode, NULL, i_data,
|
||||
level, first, count, num);
|
||||
if (ret)
|
||||
goto err;
|
||||
if (count > max - first)
|
||||
count -= max - first;
|
||||
else
|
||||
break;
|
||||
first = 0;
|
||||
end_range:
|
||||
partial2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);
|
||||
if (nr2) {
|
||||
if (partial2 == chain2) {
|
||||
/*
|
||||
* Remember, end is exclusive so here we're at
|
||||
* the start of the next level we're not going
|
||||
* to free. Everything was covered by the start
|
||||
* of the range.
|
||||
*/
|
||||
return 0;
|
||||
} else {
|
||||
/* Shared branch grows from an indirect block */
|
||||
partial2--;
|
||||
}
|
||||
} else {
|
||||
first -= max;
|
||||
/*
|
||||
* ext4_find_shared returns Indirect structure which
|
||||
* points to the last element which should not be
|
||||
* removed by truncate. But this is end of the range
|
||||
* in punch_hole so we need to point to the next element
|
||||
*/
|
||||
partial2->p++;
|
||||
}
|
||||
i_data += num;
|
||||
if (level == 0) {
|
||||
num = 1;
|
||||
max = 1;
|
||||
|
||||
/*
|
||||
* Clear the ends of indirect blocks on the shared branch
|
||||
* at the end of the range
|
||||
*/
|
||||
while (partial2 > chain2) {
|
||||
ext4_free_branches(handle, inode, partial2->bh,
|
||||
(__le32 *)partial2->bh->b_data,
|
||||
partial2->p,
|
||||
(chain2+n2-1) - partial2);
|
||||
BUFFER_TRACE(partial2->bh, "call brelse");
|
||||
brelse(partial2->bh);
|
||||
partial2--;
|
||||
}
|
||||
goto do_indirects;
|
||||
}
|
||||
|
||||
/* Punch happened within the same level (n == n2) */
|
||||
partial = ext4_find_shared(inode, n, offsets, chain, &nr);
|
||||
partial2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);
|
||||
/*
|
||||
* ext4_find_shared returns Indirect structure which
|
||||
* points to the last element which should not be
|
||||
* removed by truncate. But this is end of the range
|
||||
* in punch_hole so we need to point to the next element
|
||||
*/
|
||||
partial2->p++;
|
||||
while ((partial > chain) || (partial2 > chain2)) {
|
||||
/* We're at the same block, so we're almost finished */
|
||||
if ((partial->bh && partial2->bh) &&
|
||||
(partial->bh->b_blocknr == partial2->bh->b_blocknr)) {
|
||||
if ((partial > chain) && (partial2 > chain2)) {
|
||||
ext4_free_branches(handle, inode, partial->bh,
|
||||
partial->p + 1,
|
||||
partial2->p,
|
||||
(chain+n-1) - partial);
|
||||
BUFFER_TRACE(partial->bh, "call brelse");
|
||||
brelse(partial->bh);
|
||||
BUFFER_TRACE(partial2->bh, "call brelse");
|
||||
brelse(partial2->bh);
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
/*
|
||||
* Clear the ends of indirect blocks on the shared branch
|
||||
* at the start of the range
|
||||
*/
|
||||
if (partial > chain) {
|
||||
ext4_free_branches(handle, inode, partial->bh,
|
||||
partial->p + 1,
|
||||
(__le32 *)partial->bh->b_data+addr_per_block,
|
||||
(chain+n-1) - partial);
|
||||
BUFFER_TRACE(partial->bh, "call brelse");
|
||||
brelse(partial->bh);
|
||||
partial--;
|
||||
}
|
||||
/*
|
||||
* Clear the ends of indirect blocks on the shared branch
|
||||
* at the end of the range
|
||||
*/
|
||||
if (partial2 > chain2) {
|
||||
ext4_free_branches(handle, inode, partial2->bh,
|
||||
(__le32 *)partial2->bh->b_data,
|
||||
partial2->p,
|
||||
(chain2+n-1) - partial2);
|
||||
BUFFER_TRACE(partial2->bh, "call brelse");
|
||||
brelse(partial2->bh);
|
||||
partial2--;
|
||||
}
|
||||
}
|
||||
|
||||
err:
|
||||
return ret;
|
||||
do_indirects:
|
||||
/* Kill the remaining (whole) subtrees */
|
||||
switch (offsets[0]) {
|
||||
default:
|
||||
if (++n >= n2)
|
||||
return 0;
|
||||
nr = i_data[EXT4_IND_BLOCK];
|
||||
if (nr) {
|
||||
ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
|
||||
i_data[EXT4_IND_BLOCK] = 0;
|
||||
}
|
||||
case EXT4_IND_BLOCK:
|
||||
if (++n >= n2)
|
||||
return 0;
|
||||
nr = i_data[EXT4_DIND_BLOCK];
|
||||
if (nr) {
|
||||
ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
|
||||
i_data[EXT4_DIND_BLOCK] = 0;
|
||||
}
|
||||
case EXT4_DIND_BLOCK:
|
||||
if (++n >= n2)
|
||||
return 0;
|
||||
nr = i_data[EXT4_TIND_BLOCK];
|
||||
if (nr) {
|
||||
ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
|
||||
i_data[EXT4_TIND_BLOCK] = 0;
|
||||
}
|
||||
case EXT4_TIND_BLOCK:
|
||||
;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -3506,7 +3506,7 @@ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
|
|||
ret = ext4_ext_remove_space(inode, first_block,
|
||||
stop_block - 1);
|
||||
else
|
||||
ret = ext4_free_hole_blocks(handle, inode, first_block,
|
||||
ret = ext4_ind_remove_space(handle, inode, first_block,
|
||||
stop_block);
|
||||
|
||||
up_write(&EXT4_I(inode)->i_data_sem);
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче