| Message ID | CAOcd+r3DHGSu5017ha+m1E9bv2YD4v-LCMBxYywNA9BaLK-DQg@mail.gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
On Thu, Dec 03, 2015 at 06:51:03PM +0200, Alex Lyakas wrote: > do_chunk_alloc returns 1 when it succeeds to allocate a new chunk. > But flush_space will not convert this to 0, and will also return 1. > As a result, reserve_metadata_bytes will think that flush_space failed, > and may potentially return this value "1" to the caller (depends how > reserve_metadata_bytes was called). The caller will also treat this as an error. > For example, btrfs_block_rsv_refill does: > > int ret = -ENOSPC; > ... > ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush); > if (!ret) { > block_rsv_add_bytes(block_rsv, num_bytes, 0); > return 0; > } > > return ret; > > So it will return -ENOSPC. It will return 1 instead of -ENOSPC. The patch looks good, I noticed this before, but I didn't manage to trigger a error for this, did you catch a error like that? Thanks, -liubo > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index 4b89680..1ba3f0d 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -4727,7 +4727,7 @@ static int flush_space(struct btrfs_root *root, > btrfs_get_alloc_profile(root, 0), > CHUNK_ALLOC_NO_FORCE); > btrfs_end_transaction(trans, root); > - if (ret == -ENOSPC) > + if (ret > 0 || ret == -ENOSPC) > ret = 0; > break; > case COMMIT_TRANS: > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 12/03/2015 11:51 AM, Alex Lyakas wrote: > do_chunk_alloc returns 1 when it succeeds to allocate a new chunk. > But flush_space will not convert this to 0, and will also return 1. > As a result, reserve_metadata_bytes will think that flush_space failed, > and may potentially return this value "1" to the caller (depends how > reserve_metadata_bytes was called). The caller will also treat this as an error. > For example, btrfs_block_rsv_refill does: > > int ret = -ENOSPC; > ... > ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush); > if (!ret) { > block_rsv_add_bytes(block_rsv, num_bytes, 0); > return 0; > } > > return ret; > > So it will return -ENOSPC. Huh nice catch. Can you add your signed off by, and you can add my Reviewed-by: Josef Bacik <jbacik@fb.com> Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Liu, I was studying on how block reservation works, and making some modifications in reserve_metadata_bytes to understand better what it does. Then suddenly I saw this problem. I guess it depends on which value of "flush" parameter is passed to reserve_metadata_bytes. Alex. On Thu, Dec 3, 2015 at 8:14 PM, Liu Bo <bo.li.liu@oracle.com> wrote: > On Thu, Dec 03, 2015 at 06:51:03PM +0200, Alex Lyakas wrote: >> do_chunk_alloc returns 1 when it succeeds to allocate a new chunk. >> But flush_space will not convert this to 0, and will also return 1. >> As a result, reserve_metadata_bytes will think that flush_space failed, >> and may potentially return this value "1" to the caller (depends how >> reserve_metadata_bytes was called). The caller will also treat this as an error. >> For example, btrfs_block_rsv_refill does: >> >> int ret = -ENOSPC; >> ... >> ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush); >> if (!ret) { >> block_rsv_add_bytes(block_rsv, num_bytes, 0); >> return 0; >> } >> >> return ret; >> >> So it will return -ENOSPC. > > It will return 1 instead of -ENOSPC. > > The patch looks good, I noticed this before, but I didn't manage to trigger a error for this, did you catch a error like that? > > Thanks, > > -liubo > >> >> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c >> index 4b89680..1ba3f0d 100644 >> --- a/fs/btrfs/extent-tree.c >> +++ b/fs/btrfs/extent-tree.c >> @@ -4727,7 +4727,7 @@ static int flush_space(struct btrfs_root *root, >> btrfs_get_alloc_profile(root, 0), >> CHUNK_ALLOC_NO_FORCE); >> btrfs_end_transaction(trans, root); >> - if (ret == -ENOSPC) >> + if (ret > 0 || ret == -ENOSPC) >> ret = 0; >> break; >> case COMMIT_TRANS: >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 4b89680..1ba3f0d 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4727,7 +4727,7 @@ static int flush_space(struct btrfs_root *root, btrfs_get_alloc_profile(root, 0), CHUNK_ALLOC_NO_FORCE); btrfs_end_transaction(trans, root); - if (ret == -ENOSPC) + if (ret > 0 || ret == -ENOSPC) ret = 0; break; case COMMIT_TRANS:
do_chunk_alloc returns 1 when it succeeds to allocate a new chunk. But flush_space will not convert this to 0, and will also return 1. As a result, reserve_metadata_bytes will think that flush_space failed, and may potentially return this value "1" to the caller (depends how reserve_metadata_bytes was called). The caller will also treat this as an error. For example, btrfs_block_rsv_refill does: int ret = -ENOSPC; ... ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush); if (!ret) { block_rsv_add_bytes(block_rsv, num_bytes, 0); return 0; } return ret; So it will return -ENOSPC. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html