diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/inode.c | 82 |
1 files changed, 65 insertions, 17 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index e6be5ebe7611..9cd12760e9dd 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -64,6 +64,8 @@ struct btrfs_iget_args { struct btrfs_dio_data { ssize_t submitted; struct extent_changeset *data_reserved; + bool data_space_reserved; + bool nocow_done; }; struct btrfs_rename_ctx { @@ -7481,6 +7483,8 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map, ret = PTR_ERR(em2); goto out; } + + dio_data->nocow_done = true; } else { /* Our caller expects us to free the input extent map. */ free_extent_map(em); @@ -7489,10 +7493,19 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map, if (nowait) return -EAGAIN; - /* We have to COW, so need to reserve metadata and data space. */ - ret = btrfs_delalloc_reserve_space(BTRFS_I(inode), - &dio_data->data_reserved, - start, len); + /* + * If we could not allocate data space before locking the file + * range and we can't do a NOCOW write, then we have to fail. + */ + if (!dio_data->data_space_reserved) + return -ENOSPC; + + /* + * We have to COW and we have already reserved data space before, + * so now we reserve only metadata. + */ + ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len, len, + false); if (ret < 0) goto out; space_reserved = true; @@ -7505,10 +7518,8 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map, *map = em; len = min(len, em->len - (start - em->start)); if (len < prev_len) - btrfs_delalloc_release_space(BTRFS_I(inode), - dio_data->data_reserved, - start + len, prev_len - len, - true); + btrfs_delalloc_release_metadata(BTRFS_I(inode), + prev_len - len, true); } /* @@ -7526,15 +7537,7 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map, out: if (ret && space_reserved) { btrfs_delalloc_release_extents(BTRFS_I(inode), len); - if (can_nocow) { - btrfs_delalloc_release_metadata(BTRFS_I(inode), len, true); - } else { - btrfs_delalloc_release_space(BTRFS_I(inode), - dio_data->data_reserved, - start, len, true); - extent_changeset_free(dio_data->data_reserved); - dio_data->data_reserved = NULL; - } + btrfs_delalloc_release_metadata(BTRFS_I(inode), len, true); } return ret; } @@ -7551,6 +7554,7 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, const bool write = !!(flags & IOMAP_WRITE); int ret = 0; u64 len = length; + const u64 data_alloc_len = length; bool unlock_extents = false; if (!write) @@ -7603,6 +7607,25 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, iomap->private = dio_data; + /* + * We always try to allocate data space and must do it before locking + * the file range, to avoid deadlocks with concurrent writes to the same + * range if the range has several extents and the writes don't expand the + * current i_size (the inode lock is taken in shared mode). If we fail to + * allocate data space here we continue and later, after locking the + * file range, we fail with ENOSPC only if we figure out we can not do a + * NOCOW write. + */ + if (write && !(flags & IOMAP_NOWAIT)) { + ret = btrfs_check_data_free_space(BTRFS_I(inode), + &dio_data->data_reserved, + start, data_alloc_len); + if (!ret) + dio_data->data_space_reserved = true; + else if (ret && !(BTRFS_I(inode)->flags & + (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC))) + goto err; + } /* * If this errors out it's because we couldn't invalidate pagecache for @@ -7677,6 +7700,24 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, unlock_extents = true; /* Recalc len in case the new em is smaller than requested */ len = min(len, em->len - (start - em->start)); + if (dio_data->data_space_reserved) { + u64 release_offset; + u64 release_len = 0; + + if (dio_data->nocow_done) { + release_offset = start; + release_len = data_alloc_len; + } else if (len < data_alloc_len) { + release_offset = start + len; + release_len = data_alloc_len - len; + } + + if (release_len > 0) + btrfs_free_reserved_data_space(BTRFS_I(inode), + dio_data->data_reserved, + release_offset, + release_len); + } } else { /* * We need to unlock only the end area that we aren't using. @@ -7721,6 +7762,13 @@ unlock_err: unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, &cached_state); err: + if (dio_data->data_space_reserved) { + btrfs_free_reserved_data_space(BTRFS_I(inode), + dio_data->data_reserved, + start, data_alloc_len); + extent_changeset_free(dio_data->data_reserved); + } + kfree(dio_data); return ret; |