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btrfs: use on-stack variable for block reserve in btrfs_replace_file_extents()

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We can avoid potential memory allocation failure in
btrfs_replace_file_extents() as the block reserve lifetime is limited to
the scope of the function. This requires +48 bytes on stack.

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba
2025-06-04 11:29:27 +02:00
parent 7ce22f62b2
commit c6aeae86b9
1 changed files with 12 additions and 17 deletions
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29
fs/btrfs/file.c
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@@ -2341,7 +2341,7 @@ int btrfs_replace_file_extents(struct btrfs_inode *inode,
u64 min_size = btrfs_calc_insert_metadata_size(fs_info, 1);
u64 ino_size = round_up(inode->vfs_inode.i_size, fs_info->sectorsize);
struct btrfs_trans_handle *trans = NULL;
struct btrfs_block_rsv *rsv;
struct btrfs_block_rsv rsv;
unsigned int rsv_count;
u64 cur_offset;
u64 len = end - start;
@@ -2350,13 +2350,9 @@ int btrfs_replace_file_extents(struct btrfs_inode *inode,
if (end <= start)
return -EINVAL;
rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
if (!rsv) {
ret = -ENOMEM;
goto out;
}
rsv->size = btrfs_calc_insert_metadata_size(fs_info, 1);
rsv->failfast = true;
btrfs_init_metadata_block_rsv(fs_info, &rsv, BTRFS_BLOCK_RSV_TEMP);
rsv.size = btrfs_calc_insert_metadata_size(fs_info, 1);
rsv.failfast = true;
/*
* 1 - update the inode
@@ -2373,14 +2369,14 @@ int btrfs_replace_file_extents(struct btrfs_inode *inode,
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out_free;
goto out_release;
}
ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, &rsv,
min_size, false);
if (WARN_ON(ret))
goto out_trans;
trans->block_rsv = rsv;
trans->block_rsv = &rsv;
cur_offset = start;
drop_args.path = path;
@@ -2496,10 +2492,10 @@ int btrfs_replace_file_extents(struct btrfs_inode *inode,
}
ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
rsv, min_size, false);
&rsv, min_size, false);
if (WARN_ON(ret))
break;
trans->block_rsv = rsv;
trans->block_rsv = &rsv;
cur_offset = drop_args.drop_end;
len = end - cur_offset;
@@ -2576,16 +2572,15 @@ int btrfs_replace_file_extents(struct btrfs_inode *inode,
out_trans:
if (!trans)
goto out_free;
goto out_release;
trans->block_rsv = &fs_info->trans_block_rsv;
if (ret)
btrfs_end_transaction(trans);
else
*trans_out = trans;
out_free:
btrfs_free_block_rsv(fs_info, rsv);
out:
out_release:
btrfs_block_rsv_release(fs_info, &rsv, (u64)-1, NULL);
return ret;
}