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android13/external/e2fsprogs/lib/ext2fs/fallocate.c

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/*
* fallocate.c -- Allocate large chunks of file.
*
* Copyright (C) 2014 Oracle.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Library
* General Public License, version 2.
* %End-Header%
*/
#include "config.h"
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include "ext2_fs.h"
#include "ext2fs.h"
#define min(a, b) ((a) < (b) ? (a) : (b))
#undef DEBUG
#ifdef DEBUG
# define dbg_printf(f, a...) do {printf(f, ## a); fflush(stdout); } while (0)
#else
# define dbg_printf(f, a...)
#endif
/*
* Extent-based fallocate code.
*
* Find runs of unmapped logical blocks by starting at start and walking the
* extents until we reach the end of the range we want.
*
* For each run of unmapped blocks, try to find the extents on either side of
* the range. If there's a left extent that can grow by at least a cluster and
* there are lblocks between start and the next lcluster after start, see if
* there's an implied cluster allocation; if so, zero the blocks (if the left
* extent is initialized) and adjust the extent. Ditto for the blocks between
* the end of the last full lcluster and end, if there's a right extent.
*
* Try to attach as much as we can to the left extent, then try to attach as
* much as we can to the right extent. For the remainder, try to allocate the
* whole range; map in whatever we get; and repeat until we're done.
*
* To attach to a left extent, figure out the maximum amount we can add to the
* extent and try to allocate that much, and append if successful. To attach
* to a right extent, figure out the max we can add to the extent, try to
* allocate that much, and prepend if successful.
*
* We need an alloc_range function that tells us how much we can allocate given
* a maximum length and one of a suggested start, a fixed start, or a fixed end
* point.
*
* Every time we modify the extent tree we also need to update the block stats.
*
* At the end, update i_blocks and i_size appropriately.
*/
static void dbg_print_extent(const char *desc EXT2FS_ATTR((unused)),
const struct ext2fs_extent *extent EXT2FS_ATTR((unused)))
{
#ifdef DEBUG
if (desc)
printf("%s: ", desc);
printf("extent: lblk %llu--%llu, len %u, pblk %llu, flags: ",
extent->e_lblk, extent->e_lblk + extent->e_len - 1,
extent->e_len, extent->e_pblk);
if (extent->e_flags & EXT2_EXTENT_FLAGS_LEAF)
fputs("LEAF ", stdout);
if (extent->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
fputs("UNINIT ", stdout);
if (extent->e_flags & EXT2_EXTENT_FLAGS_SECOND_VISIT)
fputs("2ND_VISIT ", stdout);
if (!extent->e_flags)
fputs("(none)", stdout);
fputc('\n', stdout);
fflush(stdout);
#endif
}
static errcode_t claim_range(ext2_filsys fs, struct ext2_inode *inode,
blk64_t blk, blk64_t len)
{
blk64_t clusters;
clusters = (len + EXT2FS_CLUSTER_RATIO(fs) - 1) /
EXT2FS_CLUSTER_RATIO(fs);
ext2fs_block_alloc_stats_range(fs, blk,
clusters * EXT2FS_CLUSTER_RATIO(fs), +1);
return ext2fs_iblk_add_blocks(fs, inode, clusters);
}
static errcode_t ext_falloc_helper(ext2_filsys fs,
int flags,
ext2_ino_t ino,
struct ext2_inode *inode,
ext2_extent_handle_t handle,
struct ext2fs_extent *left_ext,
struct ext2fs_extent *right_ext,
blk64_t range_start, blk64_t range_len,
blk64_t alloc_goal)
{
struct ext2fs_extent newex, ex;
int op;
blk64_t fillable, pblk, plen, x, y;
blk64_t eof_blk = 0, cluster_fill = 0;
errcode_t err;
blk_t max_extent_len, max_uninit_len, max_init_len;
#ifdef DEBUG
printf("%s: ", __func__);
if (left_ext)
printf("left_ext=%llu--%llu, ", left_ext->e_lblk,
left_ext->e_lblk + left_ext->e_len - 1);
if (right_ext)
printf("right_ext=%llu--%llu, ", right_ext->e_lblk,
right_ext->e_lblk + right_ext->e_len - 1);
printf("start=%llu len=%llu, goal=%llu\n", range_start, range_len,
alloc_goal);
fflush(stdout);
#endif
/* Can't create initialized extents past EOF? */
if (!(flags & EXT2_FALLOCATE_INIT_BEYOND_EOF))
eof_blk = EXT2_I_SIZE(inode) / fs->blocksize;
/* The allocation goal must be as far into a cluster as range_start. */
alloc_goal = (alloc_goal & ~EXT2FS_CLUSTER_MASK(fs)) |
(range_start & EXT2FS_CLUSTER_MASK(fs));
max_uninit_len = EXT_UNINIT_MAX_LEN & ~EXT2FS_CLUSTER_MASK(fs);
max_init_len = EXT_INIT_MAX_LEN & ~EXT2FS_CLUSTER_MASK(fs);
/* We must lengthen the left extent to the end of the cluster */
if (left_ext && EXT2FS_CLUSTER_RATIO(fs) > 1) {
/* How many more blocks can be attached to left_ext? */
if (left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
fillable = max_uninit_len - left_ext->e_len;
else
fillable = max_init_len - left_ext->e_len;
if (fillable > range_len)
fillable = range_len;
if (fillable == 0)
goto expand_right;
/*
* If range_start isn't on a cluster boundary, try an
* implied cluster allocation for left_ext.
*/
cluster_fill = EXT2FS_CLUSTER_RATIO(fs) -
(range_start & EXT2FS_CLUSTER_MASK(fs));
cluster_fill &= EXT2FS_CLUSTER_MASK(fs);
if (cluster_fill == 0)
goto expand_right;
if (cluster_fill > fillable)
cluster_fill = fillable;
/* Don't expand an initialized left_ext beyond EOF */
if (!(flags & EXT2_FALLOCATE_INIT_BEYOND_EOF)) {
x = left_ext->e_lblk + left_ext->e_len - 1;
dbg_printf("%s: lend=%llu newlend=%llu eofblk=%llu\n",
__func__, x, x + cluster_fill, eof_blk);
if (eof_blk >= x && eof_blk <= x + cluster_fill)
cluster_fill = eof_blk - x;
if (cluster_fill == 0)
goto expand_right;
}
err = ext2fs_extent_goto(handle, left_ext->e_lblk);
if (err)
goto expand_right;
left_ext->e_len += cluster_fill;
range_start += cluster_fill;
range_len -= cluster_fill;
alloc_goal += cluster_fill;
dbg_print_extent("ext_falloc clus left+", left_ext);
err = ext2fs_extent_replace(handle, 0, left_ext);
if (err)
goto out;
err = ext2fs_extent_fix_parents(handle);
if (err)
goto out;
/* Zero blocks */
if (!(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)) {
err = ext2fs_zero_blocks2(fs, left_ext->e_pblk +
left_ext->e_len -
cluster_fill, cluster_fill,
NULL, NULL);
if (err)
goto out;
}
}
expand_right:
/* We must lengthen the right extent to the beginning of the cluster */
if (right_ext && EXT2FS_CLUSTER_RATIO(fs) > 1) {
/* How much can we attach to right_ext? */
if (right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
fillable = max_uninit_len - right_ext->e_len;
else
fillable = max_init_len - right_ext->e_len;
if (fillable > range_len)
fillable = range_len;
if (fillable == 0)
goto try_merge;
/*
* If range_end isn't on a cluster boundary, try an implied
* cluster allocation for right_ext.
*/
cluster_fill = right_ext->e_lblk & EXT2FS_CLUSTER_MASK(fs);
if (cluster_fill == 0)
goto try_merge;
err = ext2fs_extent_goto(handle, right_ext->e_lblk);
if (err)
goto out;
if (cluster_fill > fillable)
cluster_fill = fillable;
right_ext->e_lblk -= cluster_fill;
right_ext->e_pblk -= cluster_fill;
right_ext->e_len += cluster_fill;
range_len -= cluster_fill;
dbg_print_extent("ext_falloc clus right+", right_ext);
err = ext2fs_extent_replace(handle, 0, right_ext);
if (err)
goto out;
err = ext2fs_extent_fix_parents(handle);
if (err)
goto out;
/* Zero blocks if necessary */
if (!(right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)) {
err = ext2fs_zero_blocks2(fs, right_ext->e_pblk,
cluster_fill, NULL, NULL);
if (err)
goto out;
}
}
try_merge:
/* Merge both extents together, perhaps? */
if (left_ext && right_ext) {
/* Are the two extents mergeable? */
if ((left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT) !=
(right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT))
goto try_left;
/* User requires init/uninit but extent is uninit/init. */
if (((flags & EXT2_FALLOCATE_FORCE_INIT) &&
(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)) ||
((flags & EXT2_FALLOCATE_FORCE_UNINIT) &&
!(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)))
goto try_left;
/*
* Skip initialized extent unless user wants to zero blocks
* or requires init extent.
*/
if (!(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
(!(flags & EXT2_FALLOCATE_ZERO_BLOCKS) ||
!(flags & EXT2_FALLOCATE_FORCE_INIT)))
goto try_left;
/* Will it even fit? */
x = left_ext->e_len + range_len + right_ext->e_len;
if (x > (left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT ?
max_uninit_len : max_init_len))
goto try_left;
err = ext2fs_extent_goto(handle, left_ext->e_lblk);
if (err)
goto try_left;
/* Allocate blocks */
y = left_ext->e_pblk + left_ext->e_len;
err = ext2fs_new_range(fs, EXT2_NEWRANGE_FIXED_GOAL |
EXT2_NEWRANGE_MIN_LENGTH, y,
right_ext->e_pblk - y + 1, NULL,
&pblk, &plen);
if (err)
goto try_left;
if (pblk + plen != right_ext->e_pblk)
goto try_left;
err = claim_range(fs, inode, pblk, plen);
if (err)
goto out;
/* Modify extents */
left_ext->e_len = x;
dbg_print_extent("ext_falloc merge", left_ext);
err = ext2fs_extent_replace(handle, 0, left_ext);
if (err)
goto out;
err = ext2fs_extent_fix_parents(handle);
if (err)
goto out;
err = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_LEAF, &newex);
if (err)
goto out;
err = ext2fs_extent_delete(handle, 0);
if (err)
goto out;
err = ext2fs_extent_fix_parents(handle);
if (err)
goto out;
*right_ext = *left_ext;
/* Zero blocks */
if (!(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
(flags & EXT2_FALLOCATE_ZERO_BLOCKS)) {
err = ext2fs_zero_blocks2(fs, range_start, range_len,
NULL, NULL);
if (err)
goto out;
}
return 0;
}
try_left:
/* Extend the left extent */
if (left_ext) {
/* How many more blocks can be attached to left_ext? */
if (left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
fillable = max_uninit_len - left_ext->e_len;
else if (flags & EXT2_FALLOCATE_ZERO_BLOCKS)
fillable = max_init_len - left_ext->e_len;
else
fillable = 0;
/* User requires init/uninit but extent is uninit/init. */
if (((flags & EXT2_FALLOCATE_FORCE_INIT) &&
(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)) ||
((flags & EXT2_FALLOCATE_FORCE_UNINIT) &&
!(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)))
goto try_right;
if (fillable > range_len)
fillable = range_len;
/* Don't expand an initialized left_ext beyond EOF */
x = left_ext->e_lblk + left_ext->e_len - 1;
if (!(flags & EXT2_FALLOCATE_INIT_BEYOND_EOF)) {
dbg_printf("%s: lend=%llu newlend=%llu eofblk=%llu\n",
__func__, x, x + fillable, eof_blk);
if (eof_blk >= x && eof_blk <= x + fillable)
fillable = eof_blk - x;
}
if (fillable == 0)
goto try_right;
/* Test if the right edge of the range is already mapped? */
if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
err = ext2fs_map_cluster_block(fs, ino, inode,
x + fillable, &pblk);
if (err)
goto out;
if (pblk)
fillable -= 1 + ((x + fillable)
& EXT2FS_CLUSTER_MASK(fs));
if (fillable == 0)
goto try_right;
}
/* Allocate range of blocks */
x = left_ext->e_pblk + left_ext->e_len;
err = ext2fs_new_range(fs, EXT2_NEWRANGE_FIXED_GOAL |
EXT2_NEWRANGE_MIN_LENGTH,
x, fillable, NULL, &pblk, &plen);
if (err)
goto try_right;
err = claim_range(fs, inode, pblk, plen);
if (err)
goto out;
/* Modify left_ext */
err = ext2fs_extent_goto(handle, left_ext->e_lblk);
if (err)
goto out;
range_start += plen;
range_len -= plen;
left_ext->e_len += plen;
dbg_print_extent("ext_falloc left+", left_ext);
err = ext2fs_extent_replace(handle, 0, left_ext);
if (err)
goto out;
err = ext2fs_extent_fix_parents(handle);
if (err)
goto out;
/* Zero blocks if necessary */
if (!(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
(flags & EXT2_FALLOCATE_ZERO_BLOCKS)) {
err = ext2fs_zero_blocks2(fs, pblk, plen, NULL, NULL);
if (err)
goto out;
}
}
try_right:
/* Extend the right extent */
if (right_ext) {
/* How much can we attach to right_ext? */
if (right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
fillable = max_uninit_len - right_ext->e_len;
else if (flags & EXT2_FALLOCATE_ZERO_BLOCKS)
fillable = max_init_len - right_ext->e_len;
else
fillable = 0;
/* User requires init/uninit but extent is uninit/init. */
if (((flags & EXT2_FALLOCATE_FORCE_INIT) &&
(right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)) ||
((flags & EXT2_FALLOCATE_FORCE_UNINIT) &&
!(right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)))
goto try_anywhere;
if (fillable > range_len)
fillable = range_len;
if (fillable == 0)
goto try_anywhere;
/* Test if the left edge of the range is already mapped? */
if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
err = ext2fs_map_cluster_block(fs, ino, inode,
right_ext->e_lblk - fillable, &pblk);
if (err)
goto out;
if (pblk)
fillable -= EXT2FS_CLUSTER_RATIO(fs) -
((right_ext->e_lblk - fillable)
& EXT2FS_CLUSTER_MASK(fs));
if (fillable == 0)
goto try_anywhere;
}
/*
* FIXME: It would be nice if we could handle allocating a
* variable range from a fixed end point instead of just
* skipping to the general allocator if the whole range is
* unavailable.
*/
err = ext2fs_new_range(fs, EXT2_NEWRANGE_FIXED_GOAL |
EXT2_NEWRANGE_MIN_LENGTH,
right_ext->e_pblk - fillable,
fillable, NULL, &pblk, &plen);
if (err)
goto try_anywhere;
err = claim_range(fs, inode,
pblk & ~EXT2FS_CLUSTER_MASK(fs),
plen + (pblk & EXT2FS_CLUSTER_MASK(fs)));
if (err)
goto out;
/* Modify right_ext */
err = ext2fs_extent_goto(handle, right_ext->e_lblk);
if (err)
goto out;
range_len -= plen;
right_ext->e_lblk -= plen;
right_ext->e_pblk -= plen;
right_ext->e_len += plen;
dbg_print_extent("ext_falloc right+", right_ext);
err = ext2fs_extent_replace(handle, 0, right_ext);
if (err)
goto out;
err = ext2fs_extent_fix_parents(handle);
if (err)
goto out;
/* Zero blocks if necessary */
if (!(right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
(flags & EXT2_FALLOCATE_ZERO_BLOCKS)) {
err = ext2fs_zero_blocks2(fs, pblk,
plen + cluster_fill, NULL, NULL);
if (err)
goto out;
}
}
try_anywhere:
/* Try implied cluster alloc on the left and right ends */
if (range_len > 0 && (range_start & EXT2FS_CLUSTER_MASK(fs))) {
cluster_fill = EXT2FS_CLUSTER_RATIO(fs) -
(range_start & EXT2FS_CLUSTER_MASK(fs));
cluster_fill &= EXT2FS_CLUSTER_MASK(fs);
if (cluster_fill > range_len)
cluster_fill = range_len;
newex.e_lblk = range_start;
err = ext2fs_map_cluster_block(fs, ino, inode, newex.e_lblk,
&pblk);
if (err)
goto out;
if (pblk == 0)
goto try_right_implied;
newex.e_pblk = pblk;
newex.e_len = cluster_fill;
newex.e_flags = (flags & EXT2_FALLOCATE_FORCE_INIT ? 0 :
EXT2_EXTENT_FLAGS_UNINIT);
dbg_print_extent("ext_falloc iclus left+", &newex);
ext2fs_extent_goto(handle, newex.e_lblk);
err = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT,
&ex);
if (err == EXT2_ET_NO_CURRENT_NODE)
ex.e_lblk = 0;
else if (err)
goto out;
if (ex.e_lblk > newex.e_lblk)
op = 0; /* insert before */
else
op = EXT2_EXTENT_INSERT_AFTER;
dbg_printf("%s: inserting %s lblk %llu newex=%llu\n",
__func__, op ? "after" : "before", ex.e_lblk,
newex.e_lblk);
err = ext2fs_extent_insert(handle, op, &newex);
if (err)
goto out;
err = ext2fs_extent_fix_parents(handle);
if (err)
goto out;
if (!(newex.e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
(flags & EXT2_FALLOCATE_ZERO_BLOCKS)) {
err = ext2fs_zero_blocks2(fs, newex.e_pblk,
newex.e_len, NULL, NULL);
if (err)
goto out;
}
range_start += cluster_fill;
range_len -= cluster_fill;
}
try_right_implied:
y = range_start + range_len;
if (range_len > 0 && (y & EXT2FS_CLUSTER_MASK(fs))) {
cluster_fill = y & EXT2FS_CLUSTER_MASK(fs);
if (cluster_fill > range_len)
cluster_fill = range_len;
newex.e_lblk = y & ~EXT2FS_CLUSTER_MASK(fs);
err = ext2fs_map_cluster_block(fs, ino, inode, newex.e_lblk,
&pblk);
if (err)
goto out;
if (pblk == 0)
goto no_implied;
newex.e_pblk = pblk;
newex.e_len = cluster_fill;
newex.e_flags = (flags & EXT2_FALLOCATE_FORCE_INIT ? 0 :
EXT2_EXTENT_FLAGS_UNINIT);
dbg_print_extent("ext_falloc iclus right+", &newex);
ext2fs_extent_goto(handle, newex.e_lblk);
err = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT,
&ex);
if (err == EXT2_ET_NO_CURRENT_NODE)
ex.e_lblk = 0;
else if (err)
goto out;
if (ex.e_lblk > newex.e_lblk)
op = 0; /* insert before */
else
op = EXT2_EXTENT_INSERT_AFTER;
dbg_printf("%s: inserting %s lblk %llu newex=%llu\n",
__func__, op ? "after" : "before", ex.e_lblk,
newex.e_lblk);
err = ext2fs_extent_insert(handle, op, &newex);
if (err)
goto out;
err = ext2fs_extent_fix_parents(handle);
if (err)
goto out;
if (!(newex.e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
(flags & EXT2_FALLOCATE_ZERO_BLOCKS)) {
err = ext2fs_zero_blocks2(fs, newex.e_pblk,
newex.e_len, NULL, NULL);
if (err)
goto out;
}
range_len -= cluster_fill;
}
no_implied:
if (range_len == 0)
return 0;
newex.e_lblk = range_start;
if (flags & EXT2_FALLOCATE_FORCE_INIT) {
max_extent_len = max_init_len;
newex.e_flags = 0;
} else {
max_extent_len = max_uninit_len;
newex.e_flags = EXT2_EXTENT_FLAGS_UNINIT;
}
pblk = alloc_goal;
y = range_len;
for (x = 0; x < y;) {
cluster_fill = newex.e_lblk & EXT2FS_CLUSTER_MASK(fs);
fillable = min(range_len + cluster_fill, max_extent_len);
err = ext2fs_new_range(fs, 0, pblk & ~EXT2FS_CLUSTER_MASK(fs),
fillable,
NULL, &pblk, &plen);
if (err)
goto out;
err = claim_range(fs, inode, pblk, plen);
if (err)
goto out;
/* Create extent */
newex.e_pblk = pblk + cluster_fill;
newex.e_len = plen - cluster_fill;
dbg_print_extent("ext_falloc create", &newex);
ext2fs_extent_goto(handle, newex.e_lblk);
err = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT,
&ex);
if (err == EXT2_ET_NO_CURRENT_NODE)
ex.e_lblk = 0;
else if (err)
goto out;
if (ex.e_lblk > newex.e_lblk)
op = 0; /* insert before */
else
op = EXT2_EXTENT_INSERT_AFTER;
dbg_printf("%s: inserting %s lblk %llu newex=%llu\n",
__func__, op ? "after" : "before", ex.e_lblk,
newex.e_lblk);
err = ext2fs_extent_insert(handle, op, &newex);
if (err)
goto out;
err = ext2fs_extent_fix_parents(handle);
if (err)
goto out;
if (!(newex.e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
(flags & EXT2_FALLOCATE_ZERO_BLOCKS)) {
err = ext2fs_zero_blocks2(fs, pblk, plen, NULL, NULL);
if (err)
goto out;
}
/* Update variables at end of loop */
x += plen - cluster_fill;
range_len -= plen - cluster_fill;
newex.e_lblk += plen - cluster_fill;
pblk += plen - cluster_fill;
if (pblk >= ext2fs_blocks_count(fs->super))
pblk = fs->super->s_first_data_block;
}
out:
return err;
}
static errcode_t extent_fallocate(ext2_filsys fs, int flags, ext2_ino_t ino,
struct ext2_inode *inode, blk64_t goal,
blk64_t start, blk64_t len)
{
ext2_extent_handle_t handle;
struct ext2fs_extent left_extent, right_extent;
struct ext2fs_extent *left_adjacent, *right_adjacent;
errcode_t err;
blk64_t range_start, range_end = 0, end, next;
blk64_t count, goal_distance;
end = start + len - 1;
err = ext2fs_extent_open2(fs, ino, inode, &handle);
if (err)
return err;
/*
* Find the extent closest to the start of the alloc range. We don't
* check the return value because _goto() sets the current node to the
* next-lowest extent if 'start' is in a hole; or the next-highest
* extent if there aren't any lower ones; or doesn't set a current node
* if there was a real error reading the extent tree. In that case,
* _get() will error out.
*/
start_again:
ext2fs_extent_goto(handle, start);
err = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &left_extent);
if (err == EXT2_ET_NO_CURRENT_NODE) {
blk64_t max_blocks = ext2fs_blocks_count(fs->super);
if (goal == ~0ULL)
goal = ext2fs_find_inode_goal(fs, ino, inode, start);
err = ext2fs_find_first_zero_block_bitmap2(fs->block_map,
goal, max_blocks - 1, &goal);
goal += start;
err = ext_falloc_helper(fs, flags, ino, inode, handle, NULL,
NULL, start, len, goal);
goto errout;
} else if (err)
goto errout;
dbg_print_extent("ext_falloc initial", &left_extent);
next = left_extent.e_lblk + left_extent.e_len;
if (left_extent.e_lblk > start) {
/* The nearest extent we found was beyond start??? */
goal = left_extent.e_pblk - (left_extent.e_lblk - start);
err = ext_falloc_helper(fs, flags, ino, inode, handle, NULL,
&left_extent, start,
left_extent.e_lblk - start, goal);
if (err)
goto errout;
goto start_again;
} else if (next >= start) {
range_start = next;
left_adjacent = &left_extent;
} else {
range_start = start;
left_adjacent = NULL;
}
goal = left_extent.e_pblk + (range_start - left_extent.e_lblk);
do {
err = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_LEAF,
&right_extent);
dbg_printf("%s: ino=%d get next =%d\n", __func__, ino,
(int)err);
dbg_print_extent("ext_falloc next", &right_extent);
/* Stop if we've seen this extent before */
if (!err && right_extent.e_lblk <= left_extent.e_lblk)
err = EXT2_ET_EXTENT_NO_NEXT;
if (err && err != EXT2_ET_EXTENT_NO_NEXT)
goto errout;
if (err == EXT2_ET_EXTENT_NO_NEXT ||
right_extent.e_lblk > end + 1) {
range_end = end;
right_adjacent = NULL;
} else {
/* Handle right_extent.e_lblk <= end */
range_end = right_extent.e_lblk - 1;
right_adjacent = &right_extent;
}
goal_distance = range_start - next;
if (err != EXT2_ET_EXTENT_NO_NEXT &&
goal_distance > (range_end - right_extent.e_lblk))
goal = right_extent.e_pblk -
(right_extent.e_lblk - range_start);
dbg_printf("%s: ino=%d rstart=%llu rend=%llu\n", __func__, ino,
range_start, range_end);
err = 0;
if (range_start <= range_end) {
count = range_end - range_start + 1;
err = ext_falloc_helper(fs, flags, ino, inode, handle,
left_adjacent, right_adjacent,
range_start, count, goal);
if (err)
goto errout;
}
if (range_end == end)
break;
err = ext2fs_extent_goto(handle, right_extent.e_lblk);
if (err)
goto errout;
next = right_extent.e_lblk + right_extent.e_len;
left_extent = right_extent;
left_adjacent = &left_extent;
range_start = next;
goal = left_extent.e_pblk + (range_start - left_extent.e_lblk);
} while (range_end < end);
errout:
ext2fs_extent_free(handle);
return err;
}
/*
* Map physical blocks to a range of logical blocks within a file. The range
* of logical blocks are (start, start + len). If there are already extents,
* the mappings will try to extend the mappings; otherwise, it will try to map
* start as if logical block 0 points to goal. If goal is ~0ULL, then the goal
* is calculated based on the inode group.
*
* Flags:
* - EXT2_FALLOCATE_ZERO_BLOCKS: Zero the blocks that are allocated.
* - EXT2_FALLOCATE_FORCE_INIT: Create only initialized extents.
* - EXT2_FALLOCATE_FORCE_UNINIT: Create only uninitialized extents.
* - EXT2_FALLOCATE_INIT_BEYOND_EOF: Create extents beyond EOF.
*
* If neither FORCE_INIT nor FORCE_UNINIT are specified, this function will
* try to expand any extents it finds, zeroing blocks as necessary.
*/
errcode_t ext2fs_fallocate(ext2_filsys fs, int flags, ext2_ino_t ino,
struct ext2_inode *inode, blk64_t goal,
blk64_t start, blk64_t len)
{
struct ext2_inode inode_buf;
blk64_t blk, x, zero_blk, last = 0;
int zero_len = 0;
errcode_t err;
if (((flags & EXT2_FALLOCATE_FORCE_INIT) &&
(flags & EXT2_FALLOCATE_FORCE_UNINIT)) ||
(flags & ~EXT2_FALLOCATE_ALL_FLAGS))
return EXT2_ET_INVALID_ARGUMENT;
if (len > ext2fs_blocks_count(fs->super))
return EXT2_ET_BLOCK_ALLOC_FAIL;
else if (len == 0)
return 0;
/* Read inode structure if necessary */
if (!inode) {
err = ext2fs_read_inode(fs, ino, &inode_buf);
if (err)
return err;
inode = &inode_buf;
}
dbg_printf("%s: ino=%d start=%llu len=%llu goal=%llu\n", __func__, ino,
start, len, goal);
if (inode->i_flags & EXT4_EXTENTS_FL) {
err = extent_fallocate(fs, flags, ino, inode, goal, start, len);
goto out;
}
/* XXX: Allocate a bunch of blocks the slow way */
for (blk = start; blk < start + len; blk++) {
err = ext2fs_bmap2(fs, ino, inode, NULL, 0, blk, 0, &x);
if (err)
return err;
if (x)
continue;
err = ext2fs_bmap2(fs, ino, inode, NULL, BMAP_ALLOC,
blk, 0, &x);
if (err)
goto errout;
if ((zero_len && (x != last+1)) ||
(zero_len >= 65536)) {
err = ext2fs_zero_blocks2(fs, zero_blk, zero_len,
NULL, NULL);
zero_len = 0;
if (err)
goto errout;
}
if (zero_len == 0) {
zero_blk = x;
zero_len = 1;
} else {
zero_len++;
}
last = x;
}
out:
if (inode == &inode_buf)
ext2fs_write_inode(fs, ino, inode);
errout:
if (zero_len)
ext2fs_zero_blocks2(fs, zero_blk, zero_len, NULL, NULL);
return err;
}
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