diff options
Diffstat (limited to 'fs/btrfs/file.c')
| -rw-r--r-- | fs/btrfs/file.c | 125 |
1 files changed, 114 insertions, 11 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 5ffde5603686..2d70849cec92 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1312,6 +1312,56 @@ fail: } +static noinline int check_can_nocow(struct inode *inode, loff_t pos, + size_t *write_bytes) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_ordered_extent *ordered; + u64 lockstart, lockend; + u64 num_bytes; + int ret; + + lockstart = round_down(pos, root->sectorsize); + lockend = lockstart + round_up(*write_bytes, root->sectorsize) - 1; + + while (1) { + lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend); + ordered = btrfs_lookup_ordered_range(inode, lockstart, + lockend - lockstart + 1); + if (!ordered) { + break; + } + unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend); + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + } + + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend); + return PTR_ERR(trans); + } + + num_bytes = lockend - lockstart + 1; + ret = can_nocow_extent(trans, inode, lockstart, &num_bytes, NULL, NULL, + NULL); + btrfs_end_transaction(trans, root); + if (ret <= 0) { + ret = 0; + } else { + clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, + EXTENT_DIRTY | EXTENT_DELALLOC | + EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0, + NULL, GFP_NOFS); + *write_bytes = min_t(size_t, *write_bytes, num_bytes); + } + + unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend); + + return ret; +} + static noinline ssize_t __btrfs_buffered_write(struct file *file, struct iov_iter *i, loff_t pos) @@ -1319,10 +1369,12 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file, struct inode *inode = file_inode(file); struct btrfs_root *root = BTRFS_I(inode)->root; struct page **pages = NULL; + u64 release_bytes = 0; unsigned long first_index; size_t num_written = 0; int nrptrs; int ret = 0; + bool only_release_metadata = false; bool force_page_uptodate = false; nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) / @@ -1343,6 +1395,7 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file, offset); size_t num_pages = (write_bytes + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; + size_t reserve_bytes; size_t dirty_pages; size_t copied; @@ -1357,11 +1410,41 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file, break; } - ret = btrfs_delalloc_reserve_space(inode, - num_pages << PAGE_CACHE_SHIFT); + reserve_bytes = num_pages << PAGE_CACHE_SHIFT; + ret = btrfs_check_data_free_space(inode, reserve_bytes); + if (ret == -ENOSPC && + (BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | + BTRFS_INODE_PREALLOC))) { + ret = check_can_nocow(inode, pos, &write_bytes); + if (ret > 0) { + only_release_metadata = true; + /* + * our prealloc extent may be smaller than + * write_bytes, so scale down. + */ + num_pages = (write_bytes + offset + + PAGE_CACHE_SIZE - 1) >> + PAGE_CACHE_SHIFT; + reserve_bytes = num_pages << PAGE_CACHE_SHIFT; + ret = 0; + } else { + ret = -ENOSPC; + } + } + if (ret) break; + ret = btrfs_delalloc_reserve_metadata(inode, reserve_bytes); + if (ret) { + if (!only_release_metadata) + btrfs_free_reserved_data_space(inode, + reserve_bytes); + break; + } + + release_bytes = reserve_bytes; + /* * This is going to setup the pages array with the number of * pages we want, so we don't really need to worry about the @@ -1370,11 +1453,8 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file, ret = prepare_pages(root, file, pages, num_pages, pos, first_index, write_bytes, force_page_uptodate); - if (ret) { - btrfs_delalloc_release_space(inode, - num_pages << PAGE_CACHE_SHIFT); + if (ret) break; - } copied = btrfs_copy_from_user(pos, num_pages, write_bytes, pages, i); @@ -1404,30 +1484,46 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file, * managed to copy. */ if (num_pages > dirty_pages) { + release_bytes = (num_pages - dirty_pages) << + PAGE_CACHE_SHIFT; if (copied > 0) { spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents++; spin_unlock(&BTRFS_I(inode)->lock); } - btrfs_delalloc_release_space(inode, - (num_pages - dirty_pages) << - PAGE_CACHE_SHIFT); + if (only_release_metadata) + btrfs_delalloc_release_metadata(inode, + release_bytes); + else + btrfs_delalloc_release_space(inode, + release_bytes); } + release_bytes = dirty_pages << PAGE_CACHE_SHIFT; if (copied > 0) { ret = btrfs_dirty_pages(root, inode, pages, dirty_pages, pos, copied, NULL); if (ret) { - btrfs_delalloc_release_space(inode, - dirty_pages << PAGE_CACHE_SHIFT); btrfs_drop_pages(pages, num_pages); break; } } + release_bytes = 0; btrfs_drop_pages(pages, num_pages); + if (only_release_metadata && copied > 0) { + u64 lockstart = round_down(pos, root->sectorsize); + u64 lockend = lockstart + + (dirty_pages << PAGE_CACHE_SHIFT) - 1; + + set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, + lockend, EXTENT_NORESERVE, NULL, + NULL, GFP_NOFS); + only_release_metadata = false; + } + cond_resched(); balance_dirty_pages_ratelimited(inode->i_mapping); @@ -1440,6 +1536,13 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file, kfree(pages); + if (release_bytes) { + if (only_release_metadata) + btrfs_delalloc_release_metadata(inode, release_bytes); + else + btrfs_delalloc_release_space(inode, release_bytes); + } + return num_written ? num_written : ret; } |