Btrfs: fix blk_status_t/errno confusion

This fixes several instances of blk_status_t and bare errno ints being
mixed up, some of which are real bugs.

In the normal case, 0 matches BLK_STS_OK, so we don't observe any
effects of the missing conversion, but in case of errors or passes
through the repair/retry paths, the errors get mixed up.

The changes were identified using 'sparse', we don't have reports of the
buggy behaviour.

Fixes: 4e4cbee9 ("block: switch bios to blk_status_t")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/disk-io.c

@@ -3516,7 +3516,7 @@ static blk_status_t wait_dev_flush(struct btrfs_device *device)
 	struct bio *bio = device->flush_bio;
 
 	if (!device->flush_bio_sent)
-		return 0;
+		return BLK_STS_OK;
 
 	device->flush_bio_sent = 0;
 	wait_for_completion_io(&device->flush_wait);
@@ -3563,7 +3563,7 @@ static int barrier_all_devices(struct btrfs_fs_info *info)
 			continue;
 
 		write_dev_flush(dev);
-		dev->last_flush_error = 0;
+		dev->last_flush_error = BLK_STS_OK;
 	}
 
 	/* wait for all the barriers */

fs/btrfs/inode.c

@@ -7924,11 +7924,12 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
 	return ret;
 }
 
-static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
+static inline blk_status_t submit_dio_repair_bio(struct inode *inode,
+						 struct bio *bio,
 						 int mirror_num)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	int ret;
+	blk_status_t ret;
 
 	BUG_ON(bio_op(bio) == REQ_OP_WRITE);
 
@@ -7980,7 +7981,7 @@ static int btrfs_check_dio_repairable(struct inode *inode,
 	return 1;
 }
 
-static int dio_read_error(struct inode *inode, struct bio *failed_bio,
+static blk_status_t dio_read_error(struct inode *inode, struct bio *failed_bio,
 				   struct page *page, unsigned int pgoff,
 				   u64 start, u64 end, int failed_mirror,
 				   bio_end_io_t *repair_endio, void *repair_arg)
@@ -7993,18 +7994,19 @@ static int dio_read_error(struct inode *inode, struct bio *failed_bio,
 	int read_mode = 0;
 	int segs;
 	int ret;
+	blk_status_t status;
 
 	BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
 
 	ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
 	if (ret)
-		return ret;
+		return errno_to_blk_status(ret);
 
 	ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
 					 failed_mirror);
 	if (!ret) {
 		free_io_failure(failure_tree, io_tree, failrec);
-		return -EIO;
+		return BLK_STS_IOERR;
 	}
 
 	segs = bio_segments(failed_bio);
@@ -8022,13 +8024,13 @@ static int dio_read_error(struct inode *inode, struct bio *failed_bio,
 		    "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
 		    read_mode, failrec->this_mirror, failrec->in_validation);
 
-	ret = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
-	if (ret) {
+	status = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
+	if (status) {
 		free_io_failure(failure_tree, io_tree, failrec);
 		bio_put(bio);
 	}
 
-	return ret;
+	return status;
 }
 
 struct btrfs_retry_complete {
@@ -8065,7 +8067,7 @@ static void btrfs_retry_endio_nocsum(struct bio *bio)
 	bio_put(bio);
 }
 
-static int __btrfs_correct_data_nocsum(struct inode *inode,
+static blk_status_t __btrfs_correct_data_nocsum(struct inode *inode,
 						struct btrfs_io_bio *io_bio)
 {
 	struct btrfs_fs_info *fs_info;
@@ -8076,8 +8078,8 @@ static int __btrfs_correct_data_nocsum(struct inode *inode,
 	unsigned int pgoff;
 	u32 sectorsize;
 	int nr_sectors;
-	int ret;
-	int err = 0;
+	blk_status_t ret;
+	blk_status_t err = BLK_STS_OK;
 
 	fs_info = BTRFS_I(inode)->root->fs_info;
 	sectorsize = fs_info->sectorsize;
@@ -8183,11 +8185,12 @@ static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
 	int csum_pos;
 	bool uptodate = (err == 0);
 	int ret;
+	blk_status_t status;
 
 	fs_info = BTRFS_I(inode)->root->fs_info;
 	sectorsize = fs_info->sectorsize;
 
-	err = 0;
+	err = BLK_STS_OK;
 	start = io_bio->logical;
 	done.inode = inode;
 	io_bio->bio.bi_iter = io_bio->iter;
@@ -8209,12 +8212,12 @@ static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
 		done.start = start;
 		init_completion(&done.done);
 
-		ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
+		status = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
 					pgoff, start, start + sectorsize - 1,
-				io_bio->mirror_num,
-				btrfs_retry_endio, &done);
-		if (ret) {
-			err = errno_to_blk_status(ret);
+					io_bio->mirror_num, btrfs_retry_endio,
+					&done);
+		if (status) {
+			err = status;
 			goto next;
 		}
 
@@ -8250,7 +8253,7 @@ static blk_status_t btrfs_subio_endio_read(struct inode *inode,
 		if (unlikely(err))
 			return __btrfs_correct_data_nocsum(inode, io_bio);
 		else
-			return 0;
+			return BLK_STS_OK;
 	} else {
 		return __btrfs_subio_endio_read(inode, io_bio, err);
 	}
@@ -8423,9 +8426,9 @@ static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
 	return 0;
 }
 
-static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
-					 u64 file_offset, int skip_sum,
-					 int async_submit)
+static inline blk_status_t
+__btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, u64 file_offset,
+		       int skip_sum, int async_submit)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_dio_private *dip = bio->bi_private;
@@ -8488,6 +8491,7 @@ static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip,
 	int clone_offset = 0;
 	int clone_len;
 	int ret;
+	blk_status_t status;
 
 	map_length = orig_bio->bi_iter.bi_size;
 	submit_len = map_length;
@@ -8537,9 +8541,9 @@ static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip,
 		 */
 		atomic_inc(&dip->pending_bios);
 
-		ret = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
+		status = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
 						async_submit);
-		if (ret) {
+		if (status) {
 			bio_put(bio);
 			atomic_dec(&dip->pending_bios);
 			goto out_err;
@@ -8557,9 +8561,9 @@ static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip,
 	} while (submit_len > 0);
 
 submit:
-	ret = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
+	status = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
 					async_submit);
-	if (!ret)
+	if (!status)
 		return 0;
 
 	bio_put(bio);

fs/btrfs/raid56.c

@@ -905,7 +905,7 @@ static void raid_write_end_io(struct bio *bio)
 	if (!atomic_dec_and_test(&rbio->stripes_pending))
 		return;
 
-	err = 0;
+	err = BLK_STS_OK;
 
 	/* OK, we have read all the stripes we need to. */
 	max_errors = (rbio->operation == BTRFS_RBIO_PARITY_SCRUB) ?
@@ -1324,7 +1324,7 @@ static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
 	return;
 
 cleanup:
-	rbio_orig_end_io(rbio, -EIO);
+	rbio_orig_end_io(rbio, BLK_STS_IOERR);
 }
 
 /*
@@ -1475,7 +1475,7 @@ static void raid_rmw_end_io(struct bio *bio)
 
 cleanup:
 
-	rbio_orig_end_io(rbio, -EIO);
+	rbio_orig_end_io(rbio, BLK_STS_IOERR);
 }
 
 static void async_rmw_stripe(struct btrfs_raid_bio *rbio)
@@ -1579,7 +1579,7 @@ static int raid56_rmw_stripe(struct btrfs_raid_bio *rbio)
 	return 0;
 
 cleanup:
-	rbio_orig_end_io(rbio, -EIO);
+	rbio_orig_end_io(rbio, BLK_STS_IOERR);
 	return -EIO;
 
 finish:
@@ -1795,12 +1795,12 @@ static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
 	void **pointers;
 	int faila = -1, failb = -1;
 	struct page *page;
-	int err;
+	blk_status_t err;
 	int i;
 
 	pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
 	if (!pointers) {
-		err = -ENOMEM;
+		err = BLK_STS_RESOURCE;
 		goto cleanup_io;
 	}
 
@@ -1856,7 +1856,7 @@ static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
 					 * a bad data or Q stripe.
 					 * TODO, we should redo the xor here.
 					 */
-					err = -EIO;
+					err = BLK_STS_IOERR;
 					goto cleanup;
 				}
 				/*
@@ -1882,7 +1882,7 @@ static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
 			if (rbio->bbio->raid_map[failb] == RAID6_Q_STRIPE) {
 				if (rbio->bbio->raid_map[faila] ==
 				    RAID5_P_STRIPE) {
-					err = -EIO;
+					err = BLK_STS_IOERR;
 					goto cleanup;
 				}
 				/*
@@ -1954,13 +1954,13 @@ static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
 		}
 	}
 
-	err = 0;
+	err = BLK_STS_OK;
 cleanup:
 	kfree(pointers);
 
 cleanup_io:
 	if (rbio->operation == BTRFS_RBIO_READ_REBUILD) {
-		if (err == 0)
+		if (err == BLK_STS_OK)
 			cache_rbio_pages(rbio);
 		else
 			clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
@@ -1968,7 +1968,7 @@ static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
 		rbio_orig_end_io(rbio, err);
 	} else if (rbio->operation == BTRFS_RBIO_REBUILD_MISSING) {
 		rbio_orig_end_io(rbio, err);
-	} else if (err == 0) {
+	} else if (err == BLK_STS_OK) {
 		rbio->faila = -1;
 		rbio->failb = -1;
 
@@ -2005,7 +2005,7 @@ static void raid_recover_end_io(struct bio *bio)
 		return;
 
 	if (atomic_read(&rbio->error) > rbio->bbio->max_errors)
-		rbio_orig_end_io(rbio, -EIO);
+		rbio_orig_end_io(rbio, BLK_STS_IOERR);
 	else
 		__raid_recover_end_io(rbio);
 }
@@ -2104,7 +2104,7 @@ static int __raid56_parity_recover(struct btrfs_raid_bio *rbio)
 cleanup:
 	if (rbio->operation == BTRFS_RBIO_READ_REBUILD ||
 	    rbio->operation == BTRFS_RBIO_REBUILD_MISSING)
-		rbio_orig_end_io(rbio, -EIO);
+		rbio_orig_end_io(rbio, BLK_STS_IOERR);
 	return -EIO;
 }
 
@@ -2431,7 +2431,7 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
 	nr_data = bio_list_size(&bio_list);
 	if (!nr_data) {
 		/* Every parity is right */
-		rbio_orig_end_io(rbio, 0);
+		rbio_orig_end_io(rbio, BLK_STS_OK);
 		return;
 	}
 
@@ -2451,7 +2451,7 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
 	return;
 
 cleanup:
-	rbio_orig_end_io(rbio, -EIO);
+	rbio_orig_end_io(rbio, BLK_STS_IOERR);
 }
 
 static inline int is_data_stripe(struct btrfs_raid_bio *rbio, int stripe)
@@ -2519,7 +2519,7 @@ static void validate_rbio_for_parity_scrub(struct btrfs_raid_bio *rbio)
 	return;
 
 cleanup:
-	rbio_orig_end_io(rbio, -EIO);
+	rbio_orig_end_io(rbio, BLK_STS_IOERR);
 }
 
 /*
@@ -2633,7 +2633,7 @@ static void raid56_parity_scrub_stripe(struct btrfs_raid_bio *rbio)
 	return;
 
 cleanup:
-	rbio_orig_end_io(rbio, -EIO);
+	rbio_orig_end_io(rbio, BLK_STS_IOERR);
 	return;
 
 finish:

fs/btrfs/volumes.c

@@ -6212,7 +6212,7 @@ static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
 	}
 }
 
-int btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
+blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 			   int mirror_num, int async_submit)
 {
 	struct btrfs_device *dev;
@@ -6233,7 +6233,7 @@ int btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 				&map_length, &bbio, mirror_num, 1);
 	if (ret) {
 		btrfs_bio_counter_dec(fs_info);
-		return ret;
+		return errno_to_blk_status(ret);
 	}
 
 	total_devs = bbio->num_stripes;
@@ -6256,7 +6256,7 @@ int btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 		}
 
 		btrfs_bio_counter_dec(fs_info);
-		return ret;
+		return errno_to_blk_status(ret);
 	}
 
 	if (map_length < length) {
@@ -6283,7 +6283,7 @@ int btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 				  dev_nr, async_submit);
 	}
 	btrfs_bio_counter_dec(fs_info);
-	return 0;
+	return BLK_STS_OK;
 }
 
 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,

fs/btrfs/volumes.h

@@ -74,7 +74,7 @@ struct btrfs_device {
 	int missing;
 	int can_discard;
 	int is_tgtdev_for_dev_replace;
-	int last_flush_error;
+	blk_status_t last_flush_error;
 	int flush_bio_sent;
 
 #ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
@@ -416,7 +416,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 		      struct btrfs_fs_info *fs_info, u64 type);
 void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
-int btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
+blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 			   int mirror_num, int async_submit);
 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 		       fmode_t flags, void *holder);