btrfs: replace many BUG_ONs with proper error handling

 btrfs currently handles most errors with BUG_ON. This patch is a work-in-
 progress but aims to handle most errors other than internal logic
 errors and ENOMEM more gracefully.

 This iteration prevents most crashes but can run into lockups with
 the page lock on occasion when the timing "works out."

Signed-off-by: Jeff Mahoney <jeffm@suse.com>

1 files changed, 12 insertions, 12 deletions

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index cfd158dccdec..d11afa67c7d8 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -391,16 +391,16 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start,
                          */
                         atomic_inc(&cb->pending_bios);
                         ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
-                        BUG_ON(ret);
+                        BUG_ON(ret); /* -ENOMEM */
 
                         if (!skip_sum) {
                                 ret = btrfs_csum_one_bio(root, inode, bio,
                                                          start, 1);
-                                BUG_ON(ret);
+                                BUG_ON(ret); /* -ENOMEM */
                         }
 
                         ret = btrfs_map_bio(root, WRITE, bio, 0, 1);
-                        BUG_ON(ret);
+                        BUG_ON(ret); /* -ENOMEM */
 
                         bio_put(bio);
 
@@ -420,15 +420,15 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start,
         bio_get(bio);
 
         ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
-        BUG_ON(ret);
+        BUG_ON(ret); /* -ENOMEM */
 
         if (!skip_sum) {
                 ret = btrfs_csum_one_bio(root, inode, bio, start, 1);
-                BUG_ON(ret);
+                BUG_ON(ret); /* -ENOMEM */
         }
 
         ret = btrfs_map_bio(root, WRITE, bio, 0, 1);
-        BUG_ON(ret);
+        BUG_ON(ret); /* -ENOMEM */
 
         bio_put(bio);
         return 0;
@@ -661,7 +661,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
                         bio_get(comp_bio);
 
                         ret = btrfs_bio_wq_end_io(root->fs_info, comp_bio, 0);
-                        BUG_ON(ret);
+                        BUG_ON(ret); /* -ENOMEM */
 
                         /*
                          * inc the count before we submit the bio so
@@ -674,14 +674,14 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
                         if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
                                 ret = btrfs_lookup_bio_sums(root, inode,
                                                         comp_bio, sums);
-                                BUG_ON(ret);
+                                BUG_ON(ret); /* -ENOMEM */
                         }
                         sums += (comp_bio->bi_size + root->sectorsize - 1) /
                                 root->sectorsize;
 
                         ret = btrfs_map_bio(root, READ, comp_bio,
                                             mirror_num, 0);
-                        BUG_ON(ret);
+                        BUG_ON(ret); /* -ENOMEM */
 
                         bio_put(comp_bio);
 
@@ -697,15 +697,15 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
         bio_get(comp_bio);
 
         ret = btrfs_bio_wq_end_io(root->fs_info, comp_bio, 0);
-        BUG_ON(ret);
+        BUG_ON(ret); /* -ENOMEM */
 
         if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
                 ret = btrfs_lookup_bio_sums(root, inode, comp_bio, sums);
-                BUG_ON(ret);
+                BUG_ON(ret); /* -ENOMEM */
         }
 
         ret = btrfs_map_bio(root, READ, comp_bio, mirror_num, 0);
-        BUG_ON(ret);
+        BUG_ON(ret); /* -ENOMEM */
 
         bio_put(comp_bio);
         return 0;