| Message ID | 20171009180128.23610-1-bo.li.liu@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 9.10.2017 21:01, Liu Bo wrote: > We've avoided data losing raid profile when doing balance, but it > turns out that deleting a device could also result in the same > problem. > > This fixes the problem by creating an empty data chunk before > relocating the data chunk. > > Metadata/System chunk are supposed to have non-zero bytes all the time > so their raid profile is persistent. This patch introduces new warning: fs/btrfs/volumes.c:3523:29: note: ‘trans’ was declared here struct btrfs_trans_handle *trans; > > Reported-by: James Alandt <James.Alandt@wdc.com> > Signed-off-by: Liu Bo <bo.li.liu@oracle.com> > --- > fs/btrfs/volumes.c | 87 ++++++++++++++++++++++++++++++++++++++++++------------ > 1 file changed, 68 insertions(+), 19 deletions(-) > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 4a72c45..3f48bcd 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -144,6 +144,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, > u64 logical, u64 *length, > struct btrfs_bio **bbio_ret, > int mirror_num, int need_raid_map); > +static int btrfs_may_alloc_data_chunk(struct btrfs_fs_info *fs_info, > + u64 chunk_offset); Also there is no need to have this forward declaration, the function can just as well be put right before __btrfs_balance. Let's try and keep changes minimal. > > DEFINE_MUTEX(uuid_mutex); > static LIST_HEAD(fs_uuids); > @@ -3476,7 +3478,6 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info) > u32 count_meta = 0; > u32 count_sys = 0; > int chunk_reserved = 0; > - u64 bytes_used = 0; > > /* step one make some room on all the devices */ > devices = &fs_info->fs_devices->devices; > @@ -3635,28 +3636,22 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info) > goto loop; > } > > - ASSERT(fs_info->data_sinfo); > - spin_lock(&fs_info->data_sinfo->lock); > - bytes_used = fs_info->data_sinfo->bytes_used; > - spin_unlock(&fs_info->data_sinfo->lock); > - > - if ((chunk_type & BTRFS_BLOCK_GROUP_DATA) && > - !chunk_reserved && !bytes_used) { > - trans = btrfs_start_transaction(chunk_root, 0); > - if (IS_ERR(trans)) { > - mutex_unlock(&fs_info->delete_unused_bgs_mutex); > - ret = PTR_ERR(trans); > - goto error; > - } > - > - ret = btrfs_force_chunk_alloc(trans, fs_info, > - BTRFS_BLOCK_GROUP_DATA); > - btrfs_end_transaction(trans); > + if (!chunk_reserved) { > + /* > + * We may be relocating the only data chunk we have, > + * which could potentially end up with losing data's > + * raid profile, so lets allocate an empty one in > + * advance. > + */ > + ret = btrfs_may_alloc_data_chunk(fs_info, > + found_key.offset); > if (ret < 0) { > mutex_unlock(&fs_info->delete_unused_bgs_mutex); > + ret = PTR_ERR(trans); > goto error; > + } else if (ret == 1) { > + chunk_reserved = 1; > } > - chunk_reserved = 1; > } > > ret = btrfs_relocate_chunk(fs_info, found_key.offset); > @@ -4327,6 +4322,48 @@ int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info) > } > > /* > + * return 1 : allocate a data chunk successfully, > + * return <0: errors during allocating a data chunk, > + * return 0 : no need to allocate a data chunk. > + */ > +static int btrfs_may_alloc_data_chunk(struct btrfs_fs_info *fs_info, > + u64 chunk_offset) > +{ > + struct btrfs_block_group_cache *cache; > + u64 bytes_used; > + u64 chunk_type; > + > + cache = btrfs_lookup_block_group(fs_info, chunk_offset); > + ASSERT(cache); > + chunk_type = cache->flags; > + btrfs_put_block_group(cache); > + > + if (chunk_type & BTRFS_BLOCK_GROUP_DATA) { > + spin_lock(&fs_info->data_sinfo->lock); > + bytes_used = fs_info->data_sinfo->bytes_used; > + spin_unlock(&fs_info->data_sinfo->lock); > + > + if (!bytes_used) { > + struct btrfs_trans_handle *trans; > + int ret; > + > + trans = btrfs_join_transaction(fs_info->tree_root); > + if (IS_ERR(trans)) > + return PTR_ERR(trans); > + > + ret = btrfs_force_chunk_alloc(trans, fs_info, > + BTRFS_BLOCK_GROUP_DATA); > + btrfs_end_transaction(trans); > + if (ret < 0) > + return ret; > + > + return 1; > + } > + } > + return 0; > +} > + > +/* > * shrinking a device means finding all of the device extents past > * the new size, and then following the back refs to the chunks. > * The chunk relocation code actually frees the device extent > @@ -4419,6 +4456,18 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) > chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); > btrfs_release_path(path); > > + /* > + * We may be relocating the only data chunk we have, > + * which could potentially end up with losing data's > + * raid profile, so lets allocate an empty one in > + * advance. > + */ > + ret = btrfs_may_alloc_data_chunk(fs_info, chunk_offset); > + if (ret < 0) { > + mutex_unlock(&fs_info->delete_unused_bgs_mutex); > + goto done; > + } > + > ret = btrfs_relocate_chunk(fs_info, chunk_offset); > mutex_unlock(&fs_info->delete_unused_bgs_mutex); > if (ret && ret != -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
On Tue, Oct 10, 2017 at 09:57:46AM +0300, Nikolay Borisov wrote: > > > On 9.10.2017 21:01, Liu Bo wrote: > > We've avoided data losing raid profile when doing balance, but it > > turns out that deleting a device could also result in the same > > problem. > > > > This fixes the problem by creating an empty data chunk before > > relocating the data chunk. > > > > Metadata/System chunk are supposed to have non-zero bytes all the time > > so their raid profile is persistent. > > This patch introduces new warning: > > fs/btrfs/volumes.c:3523:29: note: ‘trans’ was declared here > struct btrfs_trans_handle *trans; > Not sure how I missed this, thanks for pointing it out. > > > > > Reported-by: James Alandt <James.Alandt@wdc.com> > > Signed-off-by: Liu Bo <bo.li.liu@oracle.com> > > --- > > fs/btrfs/volumes.c | 87 ++++++++++++++++++++++++++++++++++++++++++------------ > > 1 file changed, 68 insertions(+), 19 deletions(-) > > > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > > index 4a72c45..3f48bcd 100644 > > --- a/fs/btrfs/volumes.c > > +++ b/fs/btrfs/volumes.c > > @@ -144,6 +144,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, > > u64 logical, u64 *length, > > struct btrfs_bio **bbio_ret, > > int mirror_num, int need_raid_map); > > +static int btrfs_may_alloc_data_chunk(struct btrfs_fs_info *fs_info, > > + u64 chunk_offset); > > Also there is no need to have this forward declaration, the function can > just as well be put right before __btrfs_balance. Let's try and keep > changes minimal. > OK. > > > > DEFINE_MUTEX(uuid_mutex); > > static LIST_HEAD(fs_uuids); > > @@ -3476,7 +3478,6 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info) > > u32 count_meta = 0; > > u32 count_sys = 0; > > int chunk_reserved = 0; > > - u64 bytes_used = 0; > > > > /* step one make some room on all the devices */ > > devices = &fs_info->fs_devices->devices; > > @@ -3635,28 +3636,22 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info) > > goto loop; > > } > > > > - ASSERT(fs_info->data_sinfo); > > - spin_lock(&fs_info->data_sinfo->lock); > > - bytes_used = fs_info->data_sinfo->bytes_used; > > - spin_unlock(&fs_info->data_sinfo->lock); > > - > > - if ((chunk_type & BTRFS_BLOCK_GROUP_DATA) && > > - !chunk_reserved && !bytes_used) { > > - trans = btrfs_start_transaction(chunk_root, 0); > > - if (IS_ERR(trans)) { > > - mutex_unlock(&fs_info->delete_unused_bgs_mutex); > > - ret = PTR_ERR(trans); > > - goto error; > > - } > > - > > - ret = btrfs_force_chunk_alloc(trans, fs_info, > > - BTRFS_BLOCK_GROUP_DATA); > > - btrfs_end_transaction(trans); > > + if (!chunk_reserved) { > > + /* > > + * We may be relocating the only data chunk we have, > > + * which could potentially end up with losing data's > > + * raid profile, so lets allocate an empty one in > > + * advance. > > + */ > > + ret = btrfs_may_alloc_data_chunk(fs_info, > > + found_key.offset); > > if (ret < 0) { > > mutex_unlock(&fs_info->delete_unused_bgs_mutex); > > + ret = PTR_ERR(trans); I'll remove this ret = PTR_ERR(trans); -liubo > > goto error; > > + } else if (ret == 1) { > > + chunk_reserved = 1; > > } > > - chunk_reserved = 1; > > } > > > > ret = btrfs_relocate_chunk(fs_info, found_key.offset); > > @@ -4327,6 +4322,48 @@ int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info) > > } > > > > /* > > + * return 1 : allocate a data chunk successfully, > > + * return <0: errors during allocating a data chunk, > > + * return 0 : no need to allocate a data chunk. > > + */ > > +static int btrfs_may_alloc_data_chunk(struct btrfs_fs_info *fs_info, > > + u64 chunk_offset) > > +{ > > + struct btrfs_block_group_cache *cache; > > + u64 bytes_used; > > + u64 chunk_type; > > + > > + cache = btrfs_lookup_block_group(fs_info, chunk_offset); > > + ASSERT(cache); > > + chunk_type = cache->flags; > > + btrfs_put_block_group(cache); > > + > > + if (chunk_type & BTRFS_BLOCK_GROUP_DATA) { > > + spin_lock(&fs_info->data_sinfo->lock); > > + bytes_used = fs_info->data_sinfo->bytes_used; > > + spin_unlock(&fs_info->data_sinfo->lock); > > + > > + if (!bytes_used) { > > + struct btrfs_trans_handle *trans; > > + int ret; > > + > > + trans = btrfs_join_transaction(fs_info->tree_root); > > + if (IS_ERR(trans)) > > + return PTR_ERR(trans); > > + > > + ret = btrfs_force_chunk_alloc(trans, fs_info, > > + BTRFS_BLOCK_GROUP_DATA); > > + btrfs_end_transaction(trans); > > + if (ret < 0) > > + return ret; > > + > > + return 1; > > + } > > + } > > + return 0; > > +} > > + > > +/* > > * shrinking a device means finding all of the device extents past > > * the new size, and then following the back refs to the chunks. > > * The chunk relocation code actually frees the device extent > > @@ -4419,6 +4456,18 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) > > chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); > > btrfs_release_path(path); > > > > + /* > > + * We may be relocating the only data chunk we have, > > + * which could potentially end up with losing data's > > + * raid profile, so lets allocate an empty one in > > + * advance. > > + */ > > + ret = btrfs_may_alloc_data_chunk(fs_info, chunk_offset); > > + if (ret < 0) { > > + mutex_unlock(&fs_info->delete_unused_bgs_mutex); > > + goto done; > > + } > > + > > ret = btrfs_relocate_chunk(fs_info, chunk_offset); > > mutex_unlock(&fs_info->delete_unused_bgs_mutex); > > if (ret && ret != -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 -- 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/volumes.c b/fs/btrfs/volumes.c index 4a72c45..3f48bcd 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -144,6 +144,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, u64 logical, u64 *length, struct btrfs_bio **bbio_ret, int mirror_num, int need_raid_map); +static int btrfs_may_alloc_data_chunk(struct btrfs_fs_info *fs_info, + u64 chunk_offset); DEFINE_MUTEX(uuid_mutex); static LIST_HEAD(fs_uuids); @@ -3476,7 +3478,6 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info) u32 count_meta = 0; u32 count_sys = 0; int chunk_reserved = 0; - u64 bytes_used = 0; /* step one make some room on all the devices */ devices = &fs_info->fs_devices->devices; @@ -3635,28 +3636,22 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info) goto loop; } - ASSERT(fs_info->data_sinfo); - spin_lock(&fs_info->data_sinfo->lock); - bytes_used = fs_info->data_sinfo->bytes_used; - spin_unlock(&fs_info->data_sinfo->lock); - - if ((chunk_type & BTRFS_BLOCK_GROUP_DATA) && - !chunk_reserved && !bytes_used) { - trans = btrfs_start_transaction(chunk_root, 0); - if (IS_ERR(trans)) { - mutex_unlock(&fs_info->delete_unused_bgs_mutex); - ret = PTR_ERR(trans); - goto error; - } - - ret = btrfs_force_chunk_alloc(trans, fs_info, - BTRFS_BLOCK_GROUP_DATA); - btrfs_end_transaction(trans); + if (!chunk_reserved) { + /* + * We may be relocating the only data chunk we have, + * which could potentially end up with losing data's + * raid profile, so lets allocate an empty one in + * advance. + */ + ret = btrfs_may_alloc_data_chunk(fs_info, + found_key.offset); if (ret < 0) { mutex_unlock(&fs_info->delete_unused_bgs_mutex); + ret = PTR_ERR(trans); goto error; + } else if (ret == 1) { + chunk_reserved = 1; } - chunk_reserved = 1; } ret = btrfs_relocate_chunk(fs_info, found_key.offset); @@ -4327,6 +4322,48 @@ int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info) } /* + * return 1 : allocate a data chunk successfully, + * return <0: errors during allocating a data chunk, + * return 0 : no need to allocate a data chunk. + */ +static int btrfs_may_alloc_data_chunk(struct btrfs_fs_info *fs_info, + u64 chunk_offset) +{ + struct btrfs_block_group_cache *cache; + u64 bytes_used; + u64 chunk_type; + + cache = btrfs_lookup_block_group(fs_info, chunk_offset); + ASSERT(cache); + chunk_type = cache->flags; + btrfs_put_block_group(cache); + + if (chunk_type & BTRFS_BLOCK_GROUP_DATA) { + spin_lock(&fs_info->data_sinfo->lock); + bytes_used = fs_info->data_sinfo->bytes_used; + spin_unlock(&fs_info->data_sinfo->lock); + + if (!bytes_used) { + struct btrfs_trans_handle *trans; + int ret; + + trans = btrfs_join_transaction(fs_info->tree_root); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = btrfs_force_chunk_alloc(trans, fs_info, + BTRFS_BLOCK_GROUP_DATA); + btrfs_end_transaction(trans); + if (ret < 0) + return ret; + + return 1; + } + } + return 0; +} + +/* * shrinking a device means finding all of the device extents past * the new size, and then following the back refs to the chunks. * The chunk relocation code actually frees the device extent @@ -4419,6 +4456,18 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); btrfs_release_path(path); + /* + * We may be relocating the only data chunk we have, + * which could potentially end up with losing data's + * raid profile, so lets allocate an empty one in + * advance. + */ + ret = btrfs_may_alloc_data_chunk(fs_info, chunk_offset); + if (ret < 0) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + goto done; + } + ret = btrfs_relocate_chunk(fs_info, chunk_offset); mutex_unlock(&fs_info->delete_unused_bgs_mutex); if (ret && ret != -ENOSPC)
We've avoided data losing raid profile when doing balance, but it turns out that deleting a device could also result in the same problem. This fixes the problem by creating an empty data chunk before relocating the data chunk. Metadata/System chunk are supposed to have non-zero bytes all the time so their raid profile is persistent. Reported-by: James Alandt <James.Alandt@wdc.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> --- fs/btrfs/volumes.c | 87 ++++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 68 insertions(+), 19 deletions(-)