diff options
| -rw-r--r-- | fs/btrfs/file.c | 21 | ||||
| -rw-r--r-- | fs/btrfs/inode.c | 21 |
2 files changed, 40 insertions, 2 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 7aa184493aea..b750000b438a 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1533,6 +1533,27 @@ lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages, return ret; } +/* + * Check if we can do nocow write into the range [@pos, @pos + @write_bytes) + * + * @pos: File offset + * @write_bytes: The length to write, will be updated to the nocow writeable + * range + * @nowait: Whether this function could sleep + * + * This function will flush ordered extents in the range to ensure proper + * nocow checks for (nowait == false) case. + * + * Return: + * >0 and update @write_bytes if we can do nocow write + * 0 if we can't do nocow write + * -EAGAIN if we can't get the needed lock or there are ordered extents + * for * (nowait == true) case + * <0 if other error happened + * + * NOTE: For wait (nowait == false) calls, callers need to release the drew + * write lock of inode->root->snapshot_lock when return value > 0. + */ int btrfs_check_can_nocow(struct btrfs_inode *inode, loff_t pos, size_t *write_bytes, bool nowait) { diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a0388b21c5cc..37c864e6b5bc 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6945,8 +6945,25 @@ static struct extent_map *btrfs_new_extent_direct(struct inode *inode, } /* - * returns 1 when the nocow is safe, < 1 on error, 0 if the - * block must be cow'd + * Check if we can do nocow write into the range [@offset, @offset + @len) + * + * @offset: File offset + * @len: The length to write, will be updated to the nocow writeable + * range + * @orig_start: (optional) Return the original file offset of the file extent + * @orig_len: (optional) Return the original on-disk length of the file extent + * @ram_bytes: (optional) Return the ram_bytes of the file extent + * + * This function will flush ordered extents in the range to ensure proper + * nocow checks for (nowait == false) case. + * + * Return: + * >0 and update @len if we can do nocow write + * 0 if we can't do nocow write + * <0 if error happened + * + * NOTE: This only checks the file extents, caller is responsible to wait for + * any ordered extents. */ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, u64 *orig_start, u64 *orig_block_len, |