From: Omar Sandoval <[email protected]> The implementation resembles direct I/O: we have to flush any ordered extents, invalidate the page cache, and do the io tree/delalloc/extent map/ordered extent dance. From there, we can reuse the compression code with a minor modification to distinguish the write from writeback.
Now that read and write are implemented, this also sets the FMODE_ENCODED_IO flag in btrfs_file_open(). Signed-off-by: Omar Sandoval <[email protected]> --- fs/btrfs/compression.c | 6 +- fs/btrfs/compression.h | 5 +- fs/btrfs/ctree.h | 2 + fs/btrfs/file.c | 40 +++++++-- fs/btrfs/inode.c | 197 ++++++++++++++++++++++++++++++++++++++++- 5 files changed, 237 insertions(+), 13 deletions(-) diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index b05b361e2062..6632dd8d2e4d 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -276,7 +276,8 @@ static void end_compressed_bio_write(struct bio *bio) bio->bi_status == BLK_STS_OK); cb->compressed_pages[0]->mapping = NULL; - end_compressed_writeback(inode, cb); + if (cb->writeback) + end_compressed_writeback(inode, cb); /* note, our inode could be gone now */ /* @@ -311,7 +312,7 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start, unsigned long compressed_len, struct page **compressed_pages, unsigned long nr_pages, - unsigned int write_flags) + unsigned int write_flags, bool writeback) { struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); struct bio *bio = NULL; @@ -336,6 +337,7 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start, cb->mirror_num = 0; cb->compressed_pages = compressed_pages; cb->compressed_len = compressed_len; + cb->writeback = writeback; cb->orig_bio = NULL; cb->nr_pages = nr_pages; diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h index 4cb8be9ff88b..d4176384ec15 100644 --- a/fs/btrfs/compression.h +++ b/fs/btrfs/compression.h @@ -47,6 +47,9 @@ struct compressed_bio { /* the compression algorithm for this bio */ int compress_type; + /* Whether this is a write for writeback. */ + bool writeback; + /* number of compressed pages in the array */ unsigned long nr_pages; @@ -93,7 +96,7 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start, unsigned long compressed_len, struct page **compressed_pages, unsigned long nr_pages, - unsigned int write_flags); + unsigned int write_flags, bool writeback); blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, int mirror_num, unsigned long bio_flags); diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 3b2aa1c7218c..9e1719e82cc8 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2907,6 +2907,8 @@ int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end); void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start, u64 end, int uptodate); ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter); +ssize_t btrfs_encoded_write(struct kiocb *iocb, struct iov_iter *from, + struct encoded_iov *encoded); extern const struct dentry_operations btrfs_dentry_operations; diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 51740cee39fc..8de6ac9b4b9c 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1893,8 +1893,7 @@ static void update_time_for_write(struct inode *inode) inode_inc_iversion(inode); } -static ssize_t btrfs_file_write_iter(struct kiocb *iocb, - struct iov_iter *from) +static ssize_t btrfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) { struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); @@ -1904,14 +1903,22 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, u64 end_pos; ssize_t num_written = 0; const bool sync = iocb->ki_flags & IOCB_DSYNC; + struct encoded_iov encoded; ssize_t err; loff_t pos; size_t count; loff_t oldsize; int clean_page = 0; - if (!(iocb->ki_flags & IOCB_DIRECT) && - (iocb->ki_flags & IOCB_NOWAIT)) + if (iocb->ki_flags & IOCB_ENCODED) { + err = import_encoded_write(iocb, &encoded, from); + if (err) + return err; + } + + if ((iocb->ki_flags & IOCB_NOWAIT) && + (!(iocb->ki_flags & IOCB_DIRECT) || + (iocb->ki_flags & IOCB_ENCODED))) return -EOPNOTSUPP; if (!inode_trylock(inode)) { @@ -1920,14 +1927,27 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, inode_lock(inode); } - err = generic_write_checks(iocb, from); - if (err <= 0) { + if (iocb->ki_flags & IOCB_ENCODED) { + err = generic_encoded_write_checks(iocb, &encoded); + if (err) { + inode_unlock(inode); + return err; + } + count = encoded.len; + } else { + err = generic_write_checks(iocb, from); + if (err < 0) { + inode_unlock(inode); + return err; + } + count = iov_iter_count(from); + } + if (count == 0) { inode_unlock(inode); return err; } pos = iocb->ki_pos; - count = iov_iter_count(from); if (iocb->ki_flags & IOCB_NOWAIT) { /* * We will allocate space in case nodatacow is not set, @@ -1986,7 +2006,9 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, if (sync) atomic_inc(&BTRFS_I(inode)->sync_writers); - if (iocb->ki_flags & IOCB_DIRECT) { + if (iocb->ki_flags & IOCB_ENCODED) { + num_written = btrfs_encoded_write(iocb, from, &encoded); + } else if (iocb->ki_flags & IOCB_DIRECT) { num_written = __btrfs_direct_write(iocb, from); } else { num_written = btrfs_buffered_write(iocb, from); @@ -3461,7 +3483,7 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence) static int btrfs_file_open(struct inode *inode, struct file *filp) { - filp->f_mode |= FMODE_NOWAIT; + filp->f_mode |= FMODE_NOWAIT | FMODE_ENCODED_IO; return generic_file_open(inode, filp); } diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 174d0738d2c9..bcc5a2bed22b 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -865,7 +865,7 @@ static noinline void submit_compressed_extents(struct async_chunk *async_chunk) ins.objectid, ins.offset, async_extent->pages, async_extent->nr_pages, - async_chunk->write_flags)) { + async_chunk->write_flags, true)) { struct page *p = async_extent->pages[0]; const u64 start = async_extent->start; const u64 end = start + async_extent->ram_size - 1; @@ -11055,6 +11055,201 @@ ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter) return ret; } +ssize_t btrfs_encoded_write(struct kiocb *iocb, struct iov_iter *from, + struct encoded_iov *encoded) +{ + struct inode *inode = file_inode(iocb->ki_filp); + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct extent_changeset *data_reserved = NULL; + struct extent_state *cached_state = NULL; + int compression; + size_t orig_count; + u64 disk_num_bytes, num_bytes; + u64 start, end; + unsigned long nr_pages, i; + struct page **pages; + struct btrfs_key ins; + struct extent_map *em; + ssize_t ret; + + switch (encoded->compression) { + case ENCODED_IOV_COMPRESSION_ZLIB: + compression = BTRFS_COMPRESS_ZLIB; + break; + case ENCODED_IOV_COMPRESSION_LZO: + compression = BTRFS_COMPRESS_LZO; + break; + case ENCODED_IOV_COMPRESSION_ZSTD: + compression = BTRFS_COMPRESS_ZSTD; + break; + default: + return -EINVAL; + } + + disk_num_bytes = orig_count = iov_iter_count(from); + + /* For now, it's too hard to support bookend extents. */ + if (encoded->unencoded_len != encoded->len || + encoded->unencoded_offset != 0) + return -EINVAL; + + /* The extent size must be sane. */ + if (encoded->unencoded_len > BTRFS_MAX_UNCOMPRESSED || + disk_num_bytes > BTRFS_MAX_COMPRESSED || disk_num_bytes == 0) + return -EINVAL; + + /* + * The compressed data on disk must be sector-aligned. For convenience, + * we extend it with zeroes if it isn't. + */ + disk_num_bytes = ALIGN(disk_num_bytes, fs_info->sectorsize); + + /* + * The extent in the file must also be sector-aligned. However, we allow + * a write which ends at or extends i_size to have an unaligned length; + * we round up the extent size and set i_size to the given length. + */ + start = iocb->ki_pos; + if (!IS_ALIGNED(start, fs_info->sectorsize)) + return -EINVAL; + if (start + encoded->len >= inode->i_size) { + num_bytes = ALIGN(encoded->len, fs_info->sectorsize); + } else { + num_bytes = encoded->len; + if (!IS_ALIGNED(num_bytes, fs_info->sectorsize)) + return -EINVAL; + } + + /* + * It's valid to have compressed data which is larger than or the same + * size as the decompressed data. However, for buffered I/O, we fall + * back to writing the decompressed data if compression didn't shrink + * it. So, for now, let's not allow creating such extents. + * + * Note that for now this also implicitly prevents writing data that + * would fit in an inline extent. + */ + if (disk_num_bytes >= num_bytes) + return -EINVAL; + + end = start + num_bytes - 1; + + nr_pages = (disk_num_bytes + PAGE_SIZE - 1) >> PAGE_SHIFT; + pages = kvcalloc(nr_pages, sizeof(struct page *), GFP_USER); + if (!pages) + return -ENOMEM; + for (i = 0; i < nr_pages; i++) { + size_t bytes = min_t(size_t, PAGE_SIZE, iov_iter_count(from)); + char *kaddr; + + pages[i] = alloc_page(GFP_HIGHUSER); + if (!pages[i]) { + ret = -ENOMEM; + goto out_pages; + } + kaddr = kmap(pages[i]); + if (copy_from_iter(kaddr, bytes, from) != bytes) { + kunmap(pages[i]); + ret = -EFAULT; + goto out_pages; + } + if (bytes < PAGE_SIZE) + memset(kaddr + bytes, 0, PAGE_SIZE - bytes); + kunmap(pages[i]); + } + + for (;;) { + struct btrfs_ordered_extent *ordered; + + ret = btrfs_wait_ordered_range(inode, start, end - start + 1); + if (ret) + goto out_pages; + ret = invalidate_inode_pages2_range(inode->i_mapping, + start >> PAGE_SHIFT, + end >> PAGE_SHIFT); + if (ret) + goto out_pages; + lock_extent_bits(io_tree, start, end, &cached_state); + ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start, + end - start + 1); + if (!ordered && + !filemap_range_has_page(inode->i_mapping, start, end)) + break; + if (ordered) + btrfs_put_ordered_extent(ordered); + unlock_extent_cached(io_tree, start, end, &cached_state); + cond_resched(); + } + + ret = btrfs_delalloc_reserve_space(inode, &data_reserved, start, + num_bytes); + if (ret) + goto out_unlock; + + ret = btrfs_reserve_extent(root, num_bytes, disk_num_bytes, + disk_num_bytes, 0, 0, &ins, 1, 1); + if (ret) + goto out_delalloc_release; + + em = create_io_em(inode, start, num_bytes, start, ins.objectid, + ins.offset, ins.offset, num_bytes, compression, + BTRFS_ORDERED_COMPRESSED); + if (IS_ERR(em)) { + ret = PTR_ERR(em); + goto out_free_reserve; + } + free_extent_map(em); + + ret = btrfs_add_ordered_extent_compress(inode, start, ins.objectid, + num_bytes, ins.offset, + BTRFS_ORDERED_COMPRESSED, + compression); + if (ret) { + btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0); + goto out_free_reserve; + } + btrfs_dec_block_group_reservations(fs_info, ins.objectid); + + if (start + encoded->len > inode->i_size) + i_size_write(inode, start + encoded->len); + + unlock_extent_cached(io_tree, start, end, &cached_state); + + btrfs_delalloc_release_extents(BTRFS_I(inode), num_bytes, false); + + if (btrfs_submit_compressed_write(inode, start, num_bytes, ins.objectid, + ins.offset, pages, nr_pages, 0, + false)) { + struct page *page = pages[0]; + + page->mapping = inode->i_mapping; + btrfs_writepage_endio_finish_ordered(page, start, end, 0); + page->mapping = NULL; + ret = -EIO; + goto out_pages; + } + iocb->ki_pos += encoded->len; + return orig_count; + +out_free_reserve: + btrfs_dec_block_group_reservations(fs_info, ins.objectid); + btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1); +out_delalloc_release: + btrfs_delalloc_release_space(inode, data_reserved, start, num_bytes, + true); +out_unlock: + unlock_extent_cached(io_tree, start, end, &cached_state); +out_pages: + for (i = 0; i < nr_pages; i++) { + if (pages[i]) + put_page(pages[i]); + } + kvfree(pages); + return ret; +} + #ifdef CONFIG_SWAP /* * Add an entry indicating a block group or device which is pinned by a -- 2.23.0
