Merge tag 'for-5.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "The updates this time are more under the hood and enhancing existing
  features (subpage with compression and zoned namespaces).

  Performance related:

   - misc small inode logging improvements (+3% throughput, -11% latency
     on sample dbench workload)

   - more efficient directory logging: bulk item insertion, less tree
     searches and locking

   - speed up bulk insertion of items into a b-tree, which is used when
     logging directories, when running delayed items for directories
     (fsync and transaction commits) and when running the slow path
     (full sync) of an fsync (bulk creation run time -4%, deletion -12%)

  Core:

   - continued subpage support
      - make defragmentation work
      - make compression write work

   - zoned mode
      - support ZNS (zoned namespaces), zone capacity is number of
        usable blocks in each zone
      - add dedicated block group (zoned) for relocation, to prevent
        out of order writes in some cases
      - greedy block group reclaim, pick the ones with least usable
        space first

   - preparatory work for send protocol updates

   - error handling improvements

   - cleanups and refactoring

  Fixes:

   - lockdep warnings
      - in show_devname callback, on seeding device
      - device delete on loop device due to conversions to workqueues

   - fix deadlock between chunk allocation and chunk btree modifications

   - fix tracking of missing device count and status"

* tag 'for-5.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (140 commits)
  btrfs: remove root argument from check_item_in_log()
  btrfs: remove root argument from add_link()
  btrfs: remove root argument from btrfs_unlink_inode()
  btrfs: remove root argument from drop_one_dir_item()
  btrfs: clear MISSING device status bit in btrfs_close_one_device
  btrfs: call btrfs_check_rw_degradable only if there is a missing device
  btrfs: send: prepare for v2 protocol
  btrfs: fix comment about sector sizes supported in 64K systems
  btrfs: update device path inode time instead of bd_inode
  fs: export an inode_update_time helper
  btrfs: fix deadlock when defragging transparent huge pages
  btrfs: sysfs: convert scnprintf and snprintf to sysfs_emit
  btrfs: make btrfs_super_block size match BTRFS_SUPER_INFO_SIZE
  btrfs: update comments for chunk allocation -ENOSPC cases
  btrfs: fix deadlock between chunk allocation and chunk btree modifications
  btrfs: zoned: use greedy gc for auto reclaim
  btrfs: check-integrity: stop storing the block device name in btrfsic_dev_state
  btrfs: use btrfs_get_dev_args_from_path in dev removal ioctls
  btrfs: add a btrfs_get_dev_args_from_path helper
  btrfs: handle device lookup with btrfs_dev_lookup_args
  ...

1 files changed, 145 insertions, 141 deletions

diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index 295bbc13ace6..65cb0766e62d 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -32,19 +32,19 @@
  *     payload.
  *     One regular LZO compressed extent can have one or more segments.
  *     For inlined LZO compressed extent, only one segment is allowed.
- *     One segment represents at most one page of uncompressed data.
+ *     One segment represents at most one sector of uncompressed data.
  *
  * 2.1 Segment header
  *     Fixed size. LZO_LEN (4) bytes long, LE32.
  *     Records the total size of the segment (not including the header).
- *     Segment header never crosses page boundary, thus it's possible to
- *     have at most 3 padding zeros at the end of the page.
+ *     Segment header never crosses sector boundary, thus it's possible to
+ *     have at most 3 padding zeros at the end of the sector.
  *
  * 2.2 Data Payload
- *     Variable size. Size up limit should be lzo1x_worst_compress(PAGE_SIZE)
- *     which is 4419 for a 4KiB page.
+ *     Variable size. Size up limit should be lzo1x_worst_compress(sectorsize)
+ *     which is 4419 for a 4KiB sectorsize.
  *
- * Example:
+ * Example with 4K sectorsize:
  * Page 1:
  *          0     0x2   0x4   0x6   0x8   0xa   0xc   0xe     0x10
  * 0x0000   |  Header   | SegHdr 01 | Data payload 01 ...     |
@@ -112,170 +112,174 @@ static inline size_t read_compress_length(const char *buf)
 	return le32_to_cpu(dlen);
 }
 
+/*
+ * Will do:
+ *
+ * - Write a segment header into the destination
+ * - Copy the compressed buffer into the destination
+ * - Make sure we have enough space in the last sector to fit a segment header
+ *   If not, we will pad at most (LZO_LEN (4)) - 1 bytes of zeros.
+ *
+ * Will allocate new pages when needed.
+ */
+static int copy_compressed_data_to_page(char *compressed_data,
+					size_t compressed_size,
+					struct page **out_pages,
+					u32 *cur_out,
+					const u32 sectorsize)
+{
+	u32 sector_bytes_left;
+	u32 orig_out;
+	struct page *cur_page;
+	char *kaddr;
+
+	/*
+	 * We never allow a segment header crossing sector boundary, previous
+	 * run should ensure we have enough space left inside the sector.
+	 */
+	ASSERT((*cur_out / sectorsize) == (*cur_out + LZO_LEN - 1) / sectorsize);
+
+	cur_page = out_pages[*cur_out / PAGE_SIZE];
+	/* Allocate a new page */
+	if (!cur_page) {
+		cur_page = alloc_page(GFP_NOFS);
+		if (!cur_page)
+			return -ENOMEM;
+		out_pages[*cur_out / PAGE_SIZE] = cur_page;
+	}
+
+	kaddr = kmap(cur_page);
+	write_compress_length(kaddr + offset_in_page(*cur_out),
+			      compressed_size);
+	*cur_out += LZO_LEN;
+
+	orig_out = *cur_out;
+
+	/* Copy compressed data */
+	while (*cur_out - orig_out < compressed_size) {
+		u32 copy_len = min_t(u32, sectorsize - *cur_out % sectorsize,
+				     orig_out + compressed_size - *cur_out);
+
+		kunmap(cur_page);
+		cur_page = out_pages[*cur_out / PAGE_SIZE];
+		/* Allocate a new page */
+		if (!cur_page) {
+			cur_page = alloc_page(GFP_NOFS);
+			if (!cur_page)
+				return -ENOMEM;
+			out_pages[*cur_out / PAGE_SIZE] = cur_page;
+		}
+		kaddr = kmap(cur_page);
+
+		memcpy(kaddr + offset_in_page(*cur_out),
+		       compressed_data + *cur_out - orig_out, copy_len);
+
+		*cur_out += copy_len;
+	}
+
+	/*
+	 * Check if we can fit the next segment header into the remaining space
+	 * of the sector.
+	 */
+	sector_bytes_left = round_up(*cur_out, sectorsize) - *cur_out;
+	if (sector_bytes_left >= LZO_LEN || sector_bytes_left == 0)
+		goto out;
+
+	/* The remaining size is not enough, pad it with zeros */
+	memset(kaddr + offset_in_page(*cur_out), 0,
+	       sector_bytes_left);
+	*cur_out += sector_bytes_left;
+
+out:
+	kunmap(cur_page);
+	return 0;
+}
+
 int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
 		u64 start, struct page **pages, unsigned long *out_pages,
 		unsigned long *total_in, unsigned long *total_out)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
+	const u32 sectorsize = btrfs_sb(mapping->host->i_sb)->sectorsize;
+	struct page *page_in = NULL;
+	char *sizes_ptr;
 	int ret = 0;
-	char *data_in;
-	char *cpage_out, *sizes_ptr;
-	int nr_pages = 0;
-	struct page *in_page = NULL;
-	struct page *out_page = NULL;
-	unsigned long bytes_left;
-	unsigned long len = *total_out;
-	unsigned long nr_dest_pages = *out_pages;
-	const unsigned long max_out = nr_dest_pages * PAGE_SIZE;
-	size_t in_len;
-	size_t out_len;
-	char *buf;
-	unsigned long tot_in = 0;
-	unsigned long tot_out = 0;
-	unsigned long pg_bytes_left;
-	unsigned long out_offset;
-	unsigned long bytes;
+	/* Points to the file offset of input data */
+	u64 cur_in = start;
+	/* Points to the current output byte */
+	u32 cur_out = 0;
+	u32 len = *total_out;
 
 	*out_pages = 0;
 	*total_out = 0;
 	*total_in = 0;
 
-	in_page = find_get_page(mapping, start >> PAGE_SHIFT);
-	data_in = kmap(in_page);
-
 	/*
-	 * store the size of all chunks of compressed data in
-	 * the first 4 bytes
+	 * Skip the header for now, we will later come back and write the total
+	 * compressed size
 	 */
-	out_page = alloc_page(GFP_NOFS);
-	if (out_page == NULL) {
-		ret = -ENOMEM;
-		goto out;
-	}
-	cpage_out = kmap(out_page);
-	out_offset = LZO_LEN;
-	tot_out = LZO_LEN;
-	pages[0] = out_page;
-	nr_pages = 1;
-	pg_bytes_left = PAGE_SIZE - LZO_LEN;
-
-	/* compress at most one page of data each time */
-	in_len = min(len, PAGE_SIZE);
-	while (tot_in < len) {
-		ret = lzo1x_1_compress(data_in, in_len, workspace->cbuf,
-				       &out_len, workspace->mem);
-		if (ret != LZO_E_OK) {
-			pr_debug("BTRFS: lzo in loop returned %d\n",
-			       ret);
+	cur_out += LZO_LEN;
+	while (cur_in < start + len) {
+		char *data_in;
+		const u32 sectorsize_mask = sectorsize - 1;
+		u32 sector_off = (cur_in - start) & sectorsize_mask;
+		u32 in_len;
+		size_t out_len;
+
+		/* Get the input page first */
+		if (!page_in) {
+			page_in = find_get_page(mapping, cur_in >> PAGE_SHIFT);
+			ASSERT(page_in);
+		}
+
+		/* Compress at most one sector of data each time */
+		in_len = min_t(u32, start + len - cur_in, sectorsize - sector_off);
+		ASSERT(in_len);
+		data_in = kmap(page_in);
+		ret = lzo1x_1_compress(data_in +
+				       offset_in_page(cur_in), in_len,
+				       workspace->cbuf, &out_len,
+				       workspace->mem);
+		kunmap(page_in);
+		if (ret < 0) {
+			pr_debug("BTRFS: lzo in loop returned %d\n", ret);
 			ret = -EIO;
 			goto out;
 		}
 
-		/* store the size of this chunk of compressed data */
-		write_compress_length(cpage_out + out_offset, out_len);
-		tot_out += LZO_LEN;
-		out_offset += LZO_LEN;
-		pg_bytes_left -= LZO_LEN;
-
-		tot_in += in_len;
-		tot_out += out_len;
-
-		/* copy bytes from the working buffer into the pages */
-		buf = workspace->cbuf;
-		while (out_len) {
-			bytes = min_t(unsigned long, pg_bytes_left, out_len);
-
-			memcpy(cpage_out + out_offset, buf, bytes);
-
-			out_len -= bytes;
-			pg_bytes_left -= bytes;
-			buf += bytes;
-			out_offset += bytes;
-
-			/*
-			 * we need another page for writing out.
-			 *
-			 * Note if there's less than 4 bytes left, we just
-			 * skip to a new page.
-			 */
-			if ((out_len == 0 && pg_bytes_left < LZO_LEN) ||
-			    pg_bytes_left == 0) {
-				if (pg_bytes_left) {
-					memset(cpage_out + out_offset, 0,
-					       pg_bytes_left);
-					tot_out += pg_bytes_left;
-				}
-
-				/* we're done, don't allocate new page */
-				if (out_len == 0 && tot_in >= len)
-					break;
-
-				kunmap(out_page);
-				if (nr_pages == nr_dest_pages) {
-					out_page = NULL;
-					ret = -E2BIG;
-					goto out;
-				}
-
-				out_page = alloc_page(GFP_NOFS);
-				if (out_page == NULL) {
-					ret = -ENOMEM;
-					goto out;
-				}
-				cpage_out = kmap(out_page);
-				pages[nr_pages++] = out_page;
-
-				pg_bytes_left = PAGE_SIZE;
-				out_offset = 0;
-			}
-		}
+		ret = copy_compressed_data_to_page(workspace->cbuf, out_len,
+						   pages, &cur_out, sectorsize);
+		if (ret < 0)
+			goto out;
 
-		/* we're making it bigger, give up */
-		if (tot_in > 8192 && tot_in < tot_out) {
+		cur_in += in_len;
+
+		/*
+		 * Check if we're making it bigger after two sectors.  And if
+		 * it is so, give up.
+		 */
+		if (cur_in - start > sectorsize * 2 && cur_in - start < cur_out) {
 			ret = -E2BIG;
 			goto out;
 		}
 
-		/* we're all done */
-		if (tot_in >= len)
-			break;
-
-		if (tot_out > max_out)
-			break;
-
-		bytes_left = len - tot_in;
-		kunmap(in_page);
-		put_page(in_page);
-
-		start += PAGE_SIZE;
-		in_page = find_get_page(mapping, start >> PAGE_SHIFT);
-		data_in = kmap(in_page);
-		in_len = min(bytes_left, PAGE_SIZE);
-	}
-
-	if (tot_out >= tot_in) {
-		ret = -E2BIG;
-		goto out;
+		/* Check if we have reached page boundary */
+		if (IS_ALIGNED(cur_in, PAGE_SIZE)) {
+			put_page(page_in);
+			page_in = NULL;
+		}
 	}
 
-	/* store the size of all chunks of compressed data */
+	/* Store the size of all chunks of compressed data */
 	sizes_ptr = kmap_local_page(pages[0]);
-	write_compress_length(sizes_ptr, tot_out);
+	write_compress_length(sizes_ptr, cur_out);
 	kunmap_local(sizes_ptr);
 
 	ret = 0;
-	*total_out = tot_out;
-	*total_in = tot_in;
+	*total_out = cur_out;
+	*total_in = cur_in - start;
 out:
-	*out_pages = nr_pages;
-	if (out_page)
-		kunmap(out_page);
-
-	if (in_page) {
-		kunmap(in_page);
-		put_page(in_page);
-	}
-
+	*out_pages = DIV_ROUND_UP(cur_out, PAGE_SIZE);
 	return ret;
 }