@@ -1976,8 +1976,6 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
int ret;
bool check_prev = true;
u64 ino = btrfs_ino(inode);
- struct btrfs_block_group *bg;
- bool nocow = false;
struct can_nocow_file_extent_args nocow_args = { 0 };
path = btrfs_alloc_path();
@@ -1995,6 +1993,7 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
nocow_args.writeback_path = true;
while (1) {
+ struct btrfs_block_group *nocow_bg = NULL;
struct btrfs_ordered_extent *ordered;
struct btrfs_key found_key;
struct btrfs_file_extent_item *fi;
@@ -2005,8 +2004,6 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
int extent_type;
bool is_prealloc;
- nocow = false;
-
ret = btrfs_lookup_file_extent(NULL, root, path, ino,
cur_offset, 0);
if (ret < 0)
@@ -2065,7 +2062,7 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
if (found_key.offset > cur_offset) {
extent_end = found_key.offset;
extent_type = 0;
- goto out_check;
+ goto must_cow;
}
/*
@@ -2098,18 +2095,19 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
if (ret < 0)
goto error;
if (ret == 0)
- goto out_check;
+ goto must_cow;
ret = 0;
- bg = btrfs_inc_nocow_writers(fs_info, nocow_args.disk_bytenr);
- if (bg)
- nocow = true;
-out_check:
- /*
- * If nocow is false then record the beginning of the range
- * that needs to be COWed
- */
- if (!nocow) {
+ nocow_bg = btrfs_inc_nocow_writers(fs_info, nocow_args.disk_bytenr);
+ if (!nocow_bg) {
+must_cow:
+ /*
+ * If we can't perform NOCOW writeback for the range,
+ * then record the beginning of the range that needs to
+ * be COWed. It will be written out before the next
+ * NOCOW range if we find one, or when exiting this
+ * loop.
+ */
if (cow_start == (u64)-1)
cow_start = cur_offset;
cur_offset = extent_end;
@@ -2130,8 +2128,10 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
ret = fallback_to_cow(inode, locked_page,
cow_start, found_key.offset - 1);
cow_start = (u64)-1;
- if (ret)
+ if (ret) {
+ btrfs_dec_nocow_writers(nocow_bg);
goto error;
+ }
}
nocow_end = cur_offset + nocow_args.num_bytes - 1;
@@ -2148,6 +2148,7 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
ram_bytes, BTRFS_COMPRESS_NONE,
BTRFS_ORDERED_PREALLOC);
if (IS_ERR(em)) {
+ btrfs_dec_nocow_writers(nocow_bg);
ret = PTR_ERR(em);
goto error;
}
@@ -2161,6 +2162,7 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
? (1 << BTRFS_ORDERED_PREALLOC)
: (1 << BTRFS_ORDERED_NOCOW),
BTRFS_COMPRESS_NONE);
+ btrfs_dec_nocow_writers(nocow_bg);
if (IS_ERR(ordered)) {
if (is_prealloc) {
btrfs_drop_extent_map_range(inode, cur_offset,
@@ -2170,11 +2172,6 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
goto error;
}
- if (nocow) {
- btrfs_dec_nocow_writers(bg);
- nocow = false;
- }
-
if (btrfs_is_data_reloc_root(root))
/*
* Error handled later, as we must prevent
@@ -2215,10 +2212,10 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
goto error;
}
-error:
- if (nocow)
- btrfs_dec_nocow_writers(bg);
+ btrfs_free_path(path);
+ return 0;
+error:
/*
* If an error happened while a COW region is outstanding, cur_offset
* needs to be reset to cow_start to ensure the COW region is unlocked
@@ -2226,7 +2223,7 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
*/
if (cow_start != (u64)-1)
cur_offset = cow_start;
- if (ret && cur_offset < end)
+ if (cur_offset < end)
extent_clear_unlock_delalloc(inode, cur_offset, end,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC | EXTENT_DEFRAG |
Use the block group pointer used to track the outstanding NOCOW writes as a boolean to remove the duplicate nocow variable, and keep it contained in the main loop to simplify the logic. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/btrfs/inode.c | 47 ++++++++++++++++++++++------------------------- 1 file changed, 22 insertions(+), 25 deletions(-)