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: 4e4cbee93d56 ("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>

5 files changed, 64 insertions, 60 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 080e2ebb8aa0..f45b61fe9a9a 100644
--- a/fs/btrfs/disk-io.c
+++ b/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 */
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 95c212037095..24bcd5cd9cf2 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7924,11 +7924,12 @@ err:
         return ret;
 }
 
-static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
-                                        int mirror_num)
+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);
 
@@ -7980,10 +7981,10 @@ static int btrfs_check_dio_repairable(struct inode *inode,
         return 1;
 }
 
-static int 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)
+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)
 {
         struct io_failure_record *failrec;
         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
@@ -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 {
@@ -8065,8 +8067,8 @@ end:
         bio_put(bio);
 }
 
-static int __btrfs_correct_data_nocsum(struct inode *inode,
-                                       struct btrfs_io_bio *io_bio)
+static blk_status_t __btrfs_correct_data_nocsum(struct inode *inode,
+                                                struct btrfs_io_bio *io_bio)
 {
         struct btrfs_fs_info *fs_info;
         struct bio_vec bvec;
@@ -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 @@ try_again:
                 done.start = start;
                 init_completion(&done.done);
 
-                ret = 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);
+                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 (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,
-                                             async_submit);
-                if (ret) {
+                status = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
+                                                async_submit);
+                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,
-                                     async_submit);
-        if (!ret)
+        status = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
+                                        async_submit);
+        if (!status)
                 return 0;
 
         bio_put(bio);
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 208638384cd2..2cf6ba40f7c4 100644
--- a/fs/btrfs/raid56.c
+++ b/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 @@ write_data:
         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 @@ pstripe:
                 }
         }
 
-        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 @@ cleanup_io:
                 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 @@ out:
 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 @@ submit_write:
         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 @@ submit_write:
         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:
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e8b9a269fdde..bd679bc7a1a9 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6212,8 +6212,8 @@ 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,
-                  int mirror_num, int async_submit)
+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;
         struct bio *first_bio = bio;
@@ -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,
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 6f45fd60d15a..93277fc60930 100644
--- a/fs/btrfs/volumes.h
+++ b/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
@@ -416,8 +416,8 @@ 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,
-                  int mirror_num, int async_submit);
+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);
 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,