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-rw-r--r--fs/btrfs/file.c161
1 files changed, 117 insertions, 44 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 47785c8a7d39..12432057a12e 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2542,17 +2542,61 @@ out_only_mutex:
return err;
}
+/* Helper structure to record which range is already reserved */
+struct falloc_range {
+ struct list_head list;
+ u64 start;
+ u64 len;
+};
+
+/*
+ * Helper function to add falloc range
+ *
+ * Caller should have locked the larger range of extent containing
+ * [start, len)
+ */
+static int add_falloc_range(struct list_head *head, u64 start, u64 len)
+{
+ struct falloc_range *prev = NULL;
+ struct falloc_range *range = NULL;
+
+ if (list_empty(head))
+ goto insert;
+
+ /*
+ * As fallocate iterate by bytenr order, we only need to check
+ * the last range.
+ */
+ prev = list_entry(head->prev, struct falloc_range, list);
+ if (prev->start + prev->len == start) {
+ prev->len += len;
+ return 0;
+ }
+insert:
+ range = kmalloc(sizeof(*range), GFP_NOFS);
+ if (!range)
+ return -ENOMEM;
+ range->start = start;
+ range->len = len;
+ list_add_tail(&range->list, head);
+ return 0;
+}
+
static long btrfs_fallocate(struct file *file, int mode,
loff_t offset, loff_t len)
{
struct inode *inode = file_inode(file);
struct extent_state *cached_state = NULL;
+ struct falloc_range *range;
+ struct falloc_range *tmp;
+ struct list_head reserve_list;
u64 cur_offset;
u64 last_byte;
u64 alloc_start;
u64 alloc_end;
u64 alloc_hint = 0;
u64 locked_end;
+ u64 actual_end = 0;
struct extent_map *em;
int blocksize = BTRFS_I(inode)->root->sectorsize;
int ret;
@@ -2568,14 +2612,12 @@ static long btrfs_fallocate(struct file *file, int mode,
return btrfs_punch_hole(inode, offset, len);
/*
- * Make sure we have enough space before we do the
- * allocation.
- * XXX: The behavior must be changed to do accurate check first
- * and then check data reserved space.
+ * Only trigger disk allocation, don't trigger qgroup reserve
+ *
+ * For qgroup space, it will be checked later.
*/
- ret = btrfs_check_data_free_space(inode, alloc_start,
- alloc_end - alloc_start);
- if (ret)
+ ret = btrfs_alloc_data_chunk_ondemand(inode, alloc_end - alloc_start);
+ if (ret < 0)
return ret;
mutex_lock(&inode->i_mutex);
@@ -2583,6 +2625,13 @@ static long btrfs_fallocate(struct file *file, int mode,
if (ret)
goto out;
+ /*
+ * TODO: Move these two operations after we have checked
+ * accurate reserved space, or fallocate can still fail but
+ * with page truncated or size expanded.
+ *
+ * But that's a minor problem and won't do much harm BTW.
+ */
if (alloc_start > inode->i_size) {
ret = btrfs_cont_expand(inode, i_size_read(inode),
alloc_start);
@@ -2641,10 +2690,10 @@ static long btrfs_fallocate(struct file *file, int mode,
}
}
+ /* First, check if we exceed the qgroup limit */
+ INIT_LIST_HEAD(&reserve_list);
cur_offset = alloc_start;
while (1) {
- u64 actual_end;
-
em = btrfs_get_extent(inode, NULL, 0, cur_offset,
alloc_end - cur_offset, 0);
if (IS_ERR_OR_NULL(em)) {
@@ -2657,54 +2706,78 @@ static long btrfs_fallocate(struct file *file, int mode,
last_byte = min(extent_map_end(em), alloc_end);
actual_end = min_t(u64, extent_map_end(em), offset + len);
last_byte = ALIGN(last_byte, blocksize);
-
if (em->block_start == EXTENT_MAP_HOLE ||
(cur_offset >= inode->i_size &&
!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
- ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
- last_byte - cur_offset,
- 1 << inode->i_blkbits,
- offset + len,
- &alloc_hint);
- } else if (actual_end > inode->i_size &&
- !(mode & FALLOC_FL_KEEP_SIZE)) {
- struct btrfs_trans_handle *trans;
- struct btrfs_root *root = BTRFS_I(inode)->root;
-
- /*
- * We didn't need to allocate any more space, but we
- * still extended the size of the file so we need to
- * update i_size and the inode item.
- */
- trans = btrfs_start_transaction(root, 1);
- if (IS_ERR(trans)) {
- ret = PTR_ERR(trans);
- } else {
- inode->i_ctime = CURRENT_TIME;
- i_size_write(inode, actual_end);
- btrfs_ordered_update_i_size(inode, actual_end,
- NULL);
- ret = btrfs_update_inode(trans, root, inode);
- if (ret)
- btrfs_end_transaction(trans, root);
- else
- ret = btrfs_end_transaction(trans,
- root);
+ ret = add_falloc_range(&reserve_list, cur_offset,
+ last_byte - cur_offset);
+ if (ret < 0) {
+ free_extent_map(em);
+ break;
}
+ ret = btrfs_qgroup_reserve_data(inode, cur_offset,
+ last_byte - cur_offset);
+ if (ret < 0)
+ break;
}
free_extent_map(em);
- if (ret < 0)
- break;
-
cur_offset = last_byte;
- if (cur_offset >= alloc_end) {
- ret = 0;
+ if (cur_offset >= alloc_end)
break;
+ }
+
+ /*
+ * If ret is still 0, means we're OK to fallocate.
+ * Or just cleanup the list and exit.
+ */
+ list_for_each_entry_safe(range, tmp, &reserve_list, list) {
+ if (!ret)
+ ret = btrfs_prealloc_file_range(inode, mode,
+ range->start,
+ range->len, 1 << inode->i_blkbits,
+ offset + len, &alloc_hint);
+ list_del(&range->list);
+ kfree(range);
+ }
+ if (ret < 0)
+ goto out_unlock;
+
+ if (actual_end > inode->i_size &&
+ !(mode & FALLOC_FL_KEEP_SIZE)) {
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+
+ /*
+ * We didn't need to allocate any more space, but we
+ * still extended the size of the file so we need to
+ * update i_size and the inode item.
+ */
+ trans = btrfs_start_transaction(root, 1);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ } else {
+ inode->i_ctime = CURRENT_TIME;
+ i_size_write(inode, actual_end);
+ btrfs_ordered_update_i_size(inode, actual_end, NULL);
+ ret = btrfs_update_inode(trans, root, inode);
+ if (ret)
+ btrfs_end_transaction(trans, root);
+ else
+ ret = btrfs_end_transaction(trans, root);
}
}
+out_unlock:
unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
&cached_state, GFP_NOFS);
out:
+ /*
+ * As we waited the extent range, the data_rsv_map must be empty
+ * in the range, as written data range will be released from it.
+ * And for prealloacted extent, it will also be released when
+ * its metadata is written.
+ * So this is completely used as cleanup.
+ */
+ btrfs_qgroup_free_data(inode, alloc_start, alloc_end - alloc_start);
mutex_unlock(&inode->i_mutex);
/* Let go of our reservation. */
btrfs_free_reserved_data_space(inode, alloc_start,
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.