btrfs: enhance compression error messages

Add more verbose and specific messages to all main error points in
compression code for all algorithms. Currently there's no way to know
which inode is affected or where in the data errors happened.

The messages follow a common format:

- what happened
- error code if relevant
- root and inode
- additional data like offsets or lengths

There's no helper for the messages as they differ in some details and
that would be cumbersome to generalize to a single function. As all the
errors are "almost never happens" there are the unlikely annotations
done as compression is hot path.

Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 52 insertions, 18 deletions

diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c
index 2b232b82c3a8..2a079561b2b1 100644
--- a/fs/btrfs/zstd.c
+++ b/fs/btrfs/zstd.c
@@ -19,6 +19,7 @@
 #include <linux/zstd.h>
 #include "misc.h"
 #include "fs.h"
+#include "btrfs_inode.h"
 #include "compression.h"
 #include "super.h"
 
@@ -399,8 +400,13 @@ int zstd_compress_folios(struct list_head *ws, struct address_space *mapping,
 	/* Initialize the stream */
 	stream = zstd_init_cstream(&params, len, workspace->mem,
 			workspace->size);
-	if (!stream) {
-		pr_warn("BTRFS: zstd_init_cstream failed\n");
+	if (unlikely(!stream)) {
+		struct btrfs_inode *inode = BTRFS_I(mapping->host);
+
+		btrfs_err(inode->root->fs_info,
+	"zstd compression init level %d failed, root %llu inode %llu offset %llu",
+			  workspace->req_level, btrfs_root_id(inode->root),
+			  btrfs_ino(inode), start);
 		ret = -EIO;
 		goto out;
 	}
@@ -429,9 +435,14 @@ int zstd_compress_folios(struct list_head *ws, struct address_space *mapping,
 
 		ret2 = zstd_compress_stream(stream, &workspace->out_buf,
 				&workspace->in_buf);
-		if (zstd_is_error(ret2)) {
-			pr_debug("BTRFS: zstd_compress_stream returned %d\n",
-					zstd_get_error_code(ret2));
+		if (unlikely(zstd_is_error(ret2))) {
+			struct btrfs_inode *inode = BTRFS_I(mapping->host);
+
+			btrfs_warn(inode->root->fs_info,
+"zstd compression level %d failed, error %d root %llu inode %llu offset %llu",
+				   workspace->req_level, zstd_get_error_code(ret2),
+				   btrfs_root_id(inode->root), btrfs_ino(inode),
+				   start);
 			ret = -EIO;
 			goto out;
 		}
@@ -497,9 +508,14 @@ int zstd_compress_folios(struct list_head *ws, struct address_space *mapping,
 		size_t ret2;
 
 		ret2 = zstd_end_stream(stream, &workspace->out_buf);
-		if (zstd_is_error(ret2)) {
-			pr_debug("BTRFS: zstd_end_stream returned %d\n",
-					zstd_get_error_code(ret2));
+		if (unlikely(zstd_is_error(ret2))) {
+			struct btrfs_inode *inode = BTRFS_I(mapping->host);
+
+			btrfs_err(inode->root->fs_info,
+"zstd compression end level %d failed, error %d root %llu inode %llu offset %llu",
+				  workspace->req_level, zstd_get_error_code(ret2),
+				  btrfs_root_id(inode->root), btrfs_ino(inode),
+				  start);
 			ret = -EIO;
 			goto out;
 		}
@@ -561,8 +577,12 @@ int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 
 	stream = zstd_init_dstream(
 			ZSTD_BTRFS_MAX_INPUT, workspace->mem, workspace->size);
-	if (!stream) {
-		pr_debug("BTRFS: zstd_init_dstream failed\n");
+	if (unlikely(!stream)) {
+		struct btrfs_inode *inode = cb->bbio.inode;
+
+		btrfs_err(inode->root->fs_info,
+		"zstd decompression init failed, root %llu inode %llu offset %llu",
+			  btrfs_root_id(inode->root), btrfs_ino(inode), cb->start);
 		ret = -EIO;
 		goto done;
 	}
@@ -580,9 +600,13 @@ int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 
 		ret2 = zstd_decompress_stream(stream, &workspace->out_buf,
 				&workspace->in_buf);
-		if (zstd_is_error(ret2)) {
-			pr_debug("BTRFS: zstd_decompress_stream returned %d\n",
-					zstd_get_error_code(ret2));
+		if (unlikely(zstd_is_error(ret2))) {
+			struct btrfs_inode *inode = cb->bbio.inode;
+
+			btrfs_err(inode->root->fs_info,
+		"zstd decompression failed, error %d root %llu inode %llu offset %llu",
+				  zstd_get_error_code(ret2), btrfs_root_id(inode->root),
+				  btrfs_ino(inode), cb->start);
 			ret = -EIO;
 			goto done;
 		}
@@ -637,8 +661,14 @@ int zstd_decompress(struct list_head *ws, const u8 *data_in,
 
 	stream = zstd_init_dstream(
 			ZSTD_BTRFS_MAX_INPUT, workspace->mem, workspace->size);
-	if (!stream) {
-		pr_warn("BTRFS: zstd_init_dstream failed\n");
+	if (unlikely(!stream)) {
+		struct btrfs_inode *inode = BTRFS_I(dest_page->mapping->host);
+
+		btrfs_err(inode->root->fs_info,
+		"zstd decompression init failed, root %llu inode %llu offset %llu",
+			  btrfs_root_id(inode->root), btrfs_ino(inode),
+			  page_offset(dest_page));
+		ret = -EIO;
 		goto finish;
 	}
 
@@ -655,9 +685,13 @@ int zstd_decompress(struct list_head *ws, const u8 *data_in,
 	 * one call should end the decompression.
 	 */
 	ret = zstd_decompress_stream(stream, &workspace->out_buf, &workspace->in_buf);
-	if (zstd_is_error(ret)) {
-		pr_warn_ratelimited("BTRFS: zstd_decompress_stream return %d\n",
-				    zstd_get_error_code(ret));
+	if (unlikely(zstd_is_error(ret))) {
+		struct btrfs_inode *inode = BTRFS_I(dest_page->mapping->host);
+
+		btrfs_err(inode->root->fs_info,
+		"zstd decompression failed, error %d root %llu inode %llu offset %llu",
+			  zstd_get_error_code(ret), btrfs_root_id(inode->root),
+			  btrfs_ino(inode), page_offset(dest_page));
 		goto finish;
 	}
 	to_copy = workspace->out_buf.pos;