diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 75dfb9b4d9e3cc02dcfe0263f2923d80d072c2ed..654b99af1587e83eb0076f5b0595300517dc8a04 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3033,8 +3033,9 @@ int btrfs_dirty_pages(struct inode *inode, struct page **pages, size_t num_pages, loff_t pos, size_t write_bytes, struct extent_state **cached); int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end); -int btrfs_check_can_nocow(struct btrfs_inode *inode, loff_t pos, - size_t *write_bytes, bool nowait); +int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos, + size_t *write_bytes); +void btrfs_check_nocow_unlock(struct btrfs_inode *inode); /* tree-defrag.c */ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans, diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index b750000b438aa6baff49e1e786b6e0b8ef32ca4f..760ddc11aa3f5124bbdb117a378b90df65f1e7ec 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1533,29 +1533,8 @@ 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) +static int check_can_nocow(struct btrfs_inode *inode, loff_t pos, + size_t *write_bytes, bool nowait) { struct btrfs_fs_info *fs_info = inode->root->fs_info; struct btrfs_root *root = inode->root; @@ -1563,6 +1542,9 @@ int btrfs_check_can_nocow(struct btrfs_inode *inode, loff_t pos, u64 num_bytes; int ret; + if (!(inode->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC))) + return 0; + if (!nowait && !btrfs_drew_try_write_lock(&root->snapshot_lock)) return -EAGAIN; @@ -1605,6 +1587,42 @@ int btrfs_check_can_nocow(struct btrfs_inode *inode, loff_t pos, return ret; } +static int check_nocow_nolock(struct btrfs_inode *inode, loff_t pos, + size_t *write_bytes) +{ + return check_can_nocow(inode, pos, write_bytes, true); +} + +/* + * 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 + * + * This function will flush ordered extents in the range to ensure proper + * nocow checks. + * + * 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: Callers need to release the lock by btrfs_check_nocow_unlock(). + */ +int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos, + size_t *write_bytes) +{ + return check_can_nocow(inode, pos, write_bytes, false); +} + +void btrfs_check_nocow_unlock(struct btrfs_inode *inode) +{ + btrfs_drew_write_unlock(&inode->root->snapshot_lock); +} + static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) { @@ -1612,7 +1630,6 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, loff_t pos = iocb->ki_pos; struct inode *inode = file_inode(file); struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); - struct btrfs_root *root = BTRFS_I(inode)->root; struct page **pages = NULL; struct extent_changeset *data_reserved = NULL; u64 release_bytes = 0; @@ -1668,10 +1685,8 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, ret = btrfs_check_data_free_space(inode, &data_reserved, pos, write_bytes); if (ret < 0) { - if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | - BTRFS_INODE_PREALLOC)) && - btrfs_check_can_nocow(BTRFS_I(inode), pos, - &write_bytes, false) > 0) { + if (btrfs_check_nocow_lock(BTRFS_I(inode), pos, + &write_bytes) > 0) { /* * For nodata cow case, no need to reserve * data space. @@ -1700,7 +1715,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, data_reserved, pos, write_bytes); else - btrfs_drew_write_unlock(&root->snapshot_lock); + btrfs_check_nocow_unlock(BTRFS_I(inode)); break; } @@ -1804,7 +1819,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, release_bytes = 0; if (only_release_metadata) - btrfs_drew_write_unlock(&root->snapshot_lock); + btrfs_check_nocow_unlock(BTRFS_I(inode)); if (only_release_metadata && copied > 0) { lockstart = round_down(pos, @@ -1831,7 +1846,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, if (release_bytes) { if (only_release_metadata) { - btrfs_drew_write_unlock(&root->snapshot_lock); + btrfs_check_nocow_unlock(BTRFS_I(inode)); btrfs_delalloc_release_metadata(BTRFS_I(inode), release_bytes, true); } else { @@ -1946,10 +1961,8 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, * We will allocate space in case nodatacow is not set, * so bail */ - if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | - BTRFS_INODE_PREALLOC)) || - btrfs_check_can_nocow(BTRFS_I(inode), pos, &nocow_bytes, - true) <= 0) { + if (check_nocow_nolock(BTRFS_I(inode), pos, &nocow_bytes) + <= 0) { inode_unlock(inode); return -EAGAIN; } diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 37c864e6b5bce5ed901a879f2de5e16d5b735aec..bd51365e53fb70db689b279798d7d055889a0eee 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4534,10 +4534,8 @@ int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len, ret = btrfs_check_data_free_space(inode, &data_reserved, block_start, blocksize); if (ret < 0) { - if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | - BTRFS_INODE_PREALLOC)) && - btrfs_check_can_nocow(BTRFS_I(inode), block_start, - &write_bytes, false) > 0) { + if (btrfs_check_nocow_lock(BTRFS_I(inode), block_start, + &write_bytes) > 0) { /* For nocow case, no need to reserve data space */ only_release_metadata = true; } else { @@ -4638,7 +4636,7 @@ int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len, put_page(page); out: if (only_release_metadata) - btrfs_drew_write_unlock(&BTRFS_I(inode)->root->snapshot_lock); + btrfs_check_nocow_unlock(BTRFS_I(inode)); extent_changeset_free(data_reserved); return ret; }