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,