From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:16403 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751648AbdCACUe (ORCPT ); Tue, 28 Feb 2017 21:20:34 -0500 Date: Tue, 28 Feb 2017 18:19:56 -0800 From: Liu Bo To: Qu Wenruo Cc: linux-btrfs@vger.kernel.org, David Sterba Subject: Re: [PATCH 1/7] Btrfs: create a helper for getting chunk map Message-ID: <20170301021955.GC9546@lim.localdomain> Reply-To: bo.li.liu@oracle.com References: <1487381301-865-1-git-send-email-bo.li.liu@oracle.com> <1487381301-865-2-git-send-email-bo.li.liu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Mon, Feb 20, 2017 at 11:20:33AM +0800, Qu Wenruo wrote: > > > At 02/18/2017 09:28 AM, Liu Bo wrote: > > We have similar code here and there, this merges them into a helper. > > > > Signed-off-by: Liu Bo > > Looks good overall. > > Although small nitpick inlined below. Thank you for going through this. > > --- > > fs/btrfs/extent_io.c | 3 +- > > fs/btrfs/volumes.c | 163 +++++++++++++++++---------------------------------- > > fs/btrfs/volumes.h | 2 +- > > 3 files changed, 57 insertions(+), 111 deletions(-) > > > > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c > > index 4ac383a..609ece1 100644 > > --- a/fs/btrfs/extent_io.c > > +++ b/fs/btrfs/extent_io.c > > @@ -2007,14 +2007,13 @@ int repair_io_failure(struct inode *inode, u64 start, u64 length, u64 logical, > > u64 map_length = 0; > > u64 sector; > > struct btrfs_bio *bbio = NULL; > > - struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; > > int ret; > > > > ASSERT(!(fs_info->sb->s_flags & MS_RDONLY)); > > BUG_ON(!mirror_num); > > > > /* we can't repair anything in raid56 yet */ > > - if (btrfs_is_parity_mirror(map_tree, logical, length, mirror_num)) > > + if (btrfs_is_parity_mirror(fs_info, logical, length, mirror_num)) > > Not sure if such small parameter cleanup can be split into a separate patch. > At least it's less related to the get_chunk_map() helper. > But it's not a cleanup, it is get_chunk_map() that needs @fs_info. > > return 0; > > > > bio = btrfs_io_bio_alloc(GFP_NOFS, 1); > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > > index 3c3c69c..c52b0fe 100644 > > --- a/fs/btrfs/volumes.c > > +++ b/fs/btrfs/volumes.c > > @@ -2794,10 +2794,38 @@ static int btrfs_del_sys_chunk(struct btrfs_fs_info *fs_info, > > return ret; > > } > > > > +static struct extent_map *get_chunk_map(struct btrfs_fs_info *fs_info, > > + u64 logical, u64 length) > > +{ > > + struct extent_map_tree *em_tree; > > + struct extent_map *em; > > + > > + em_tree = &fs_info->mapping_tree.map_tree; > > + read_lock(&em_tree->lock); > > + em = lookup_extent_mapping(em_tree, logical, length); > > + read_unlock(&em_tree->lock); > > + > > + if (!em) { > > + btrfs_crit(fs_info, "unable to find logical %llu len %llu", > > + logical, length); > > Nice error message, would be quite helpful when we hit some bug later. > > > + return ERR_PTR(-EINVAL); > > Normally I'd return -ENOENT, not sure what's the correct return here though. > So I tried to be consistent with the error handling of other places of searching chunk mapping tree. I think EINVAL makes sense here, either @logical or @length is not valid. > > + } > > + > > + if (em->start > logical || em->start + em->len < logical) { > > + btrfs_crit(fs_info, > > + "found a bad mapping, wanted %llu, found %llu-%llu", > > + logical, em->start, em->start + em->len); > > Better outputting @length also. > OK, I'll update it with @length. Thanks, -liubo > Thanks, > Qu > > > + free_extent_map(em); > > + return ERR_PTR(-EINVAL); > > + } > > + > > + /* callers are responsible for dropping em's ref. */ > > + return em; > > +} > > + > > int btrfs_remove_chunk(struct btrfs_trans_handle *trans, > > struct btrfs_fs_info *fs_info, u64 chunk_offset) > > { > > - struct extent_map_tree *em_tree; > > struct extent_map *em; > > struct map_lookup *map; > > u64 dev_extent_len = 0; > > @@ -2805,23 +2833,15 @@ int btrfs_remove_chunk(struct btrfs_trans_handle *trans, > > int i, ret = 0; > > struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; > > > > - em_tree = &fs_info->mapping_tree.map_tree; > > - > > - read_lock(&em_tree->lock); > > - em = lookup_extent_mapping(em_tree, chunk_offset, 1); > > - read_unlock(&em_tree->lock); > > - > > - if (!em || em->start > chunk_offset || > > - em->start + em->len < chunk_offset) { > > + em = get_chunk_map(fs_info, chunk_offset, 1); > > + if (IS_ERR(em)) { > > /* > > * This is a logic error, but we don't want to just rely on the > > * user having built with ASSERT enabled, so if ASSERT doesn't > > * do anything we still error out. > > */ > > ASSERT(0); > > - if (em) > > - free_extent_map(em); > > - return -EINVAL; > > + return PTR_ERR(em); > > } > > map = em->map_lookup; > > mutex_lock(&fs_info->chunk_mutex); > > @@ -4888,7 +4908,6 @@ int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans, > > struct btrfs_device *device; > > struct btrfs_chunk *chunk; > > struct btrfs_stripe *stripe; > > - struct extent_map_tree *em_tree; > > struct extent_map *em; > > struct map_lookup *map; > > size_t item_size; > > @@ -4897,24 +4916,9 @@ int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans, > > int i = 0; > > int ret = 0; > > > > - em_tree = &fs_info->mapping_tree.map_tree; > > - read_lock(&em_tree->lock); > > - em = lookup_extent_mapping(em_tree, chunk_offset, chunk_size); > > - read_unlock(&em_tree->lock); > > - > > - if (!em) { > > - btrfs_crit(fs_info, "unable to find logical %Lu len %Lu", > > - chunk_offset, chunk_size); > > - return -EINVAL; > > - } > > - > > - if (em->start != chunk_offset || em->len != chunk_size) { > > - btrfs_crit(fs_info, > > - "found a bad mapping, wanted %Lu-%Lu, found %Lu-%Lu", > > - chunk_offset, chunk_size, em->start, em->len); > > - free_extent_map(em); > > - return -EINVAL; > > - } > > + em = get_chunk_map(fs_info, chunk_offset, chunk_size); > > + if (IS_ERR(em)) > > + return PTR_ERR(em); > > > > map = em->map_lookup; > > item_size = btrfs_chunk_item_size(map->num_stripes); > > @@ -5057,15 +5061,12 @@ int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset) > > { > > struct extent_map *em; > > struct map_lookup *map; > > - struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; > > int readonly = 0; > > int miss_ndevs = 0; > > int i; > > > > - read_lock(&map_tree->map_tree.lock); > > - em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1); > > - read_unlock(&map_tree->map_tree.lock); > > - if (!em) > > + em = get_chunk_map(fs_info, chunk_offset, 1); > > + if (IS_ERR(em)) > > return 1; > > > > map = em->map_lookup; > > @@ -5119,34 +5120,19 @@ void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree) > > > > int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len) > > { > > - struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; > > struct extent_map *em; > > struct map_lookup *map; > > - struct extent_map_tree *em_tree = &map_tree->map_tree; > > int ret; > > > > - read_lock(&em_tree->lock); > > - em = lookup_extent_mapping(em_tree, logical, len); > > - read_unlock(&em_tree->lock); > > - > > - /* > > - * We could return errors for these cases, but that could get ugly and > > - * we'd probably do the same thing which is just not do anything else > > - * and exit, so return 1 so the callers don't try to use other copies. > > - */ > > - if (!em) { > > - btrfs_crit(fs_info, "No mapping for %Lu-%Lu", logical, > > - logical+len); > > - return 1; > > - } > > - > > - if (em->start > logical || em->start + em->len < logical) { > > - btrfs_crit(fs_info, "Invalid mapping for %Lu-%Lu, got %Lu-%Lu", > > - logical, logical+len, em->start, > > - em->start + em->len); > > - free_extent_map(em); > > + em = get_chunk_map(fs_info, logical, len); > > + if (IS_ERR(em)) > > + /* > > + * We could return errors for these cases, but that could get > > + * ugly and we'd probably do the same thing which is just not do > > + * anything else and exit, so return 1 so the callers don't try > > + * to use other copies. > > + */ > > return 1; > > - } > > > > map = em->map_lookup; > > if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1)) > > @@ -5175,15 +5161,11 @@ unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info, > > { > > struct extent_map *em; > > struct map_lookup *map; > > - struct extent_map_tree *em_tree = &map_tree->map_tree; > > unsigned long len = fs_info->sectorsize; > > > > - read_lock(&em_tree->lock); > > - em = lookup_extent_mapping(em_tree, logical, len); > > - read_unlock(&em_tree->lock); > > - BUG_ON(!em); > > + em = get_chunk_map(fs_info, logical, len); > > + BUG_ON(IS_ERR(em)); > > > > - BUG_ON(em->start > logical || em->start + em->len < logical); > > map = em->map_lookup; > > if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) > > len = map->stripe_len * nr_data_stripes(map); > > @@ -5191,20 +5173,16 @@ unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info, > > return len; > > } > > > > -int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree, > > +int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info, > > u64 logical, u64 len, int mirror_num) > > { > > struct extent_map *em; > > struct map_lookup *map; > > - struct extent_map_tree *em_tree = &map_tree->map_tree; > > int ret = 0; > > > > - read_lock(&em_tree->lock); > > - em = lookup_extent_mapping(em_tree, logical, len); > > - read_unlock(&em_tree->lock); > > - BUG_ON(!em); > > + em = get_chunk_map(fs_info, logical, len); > > + BUG_ON(IS_ERR(em)); > > > > - BUG_ON(em->start > logical || em->start + em->len < logical); > > map = em->map_lookup; > > if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) > > ret = 1; > > @@ -5324,8 +5302,6 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, > > { > > struct extent_map *em; > > struct map_lookup *map; > > - struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; > > - struct extent_map_tree *em_tree = &map_tree->map_tree; > > u64 offset; > > u64 stripe_offset; > > u64 stripe_end_offset; > > @@ -5347,23 +5323,9 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, > > u64 physical_to_patch_in_first_stripe = 0; > > u64 raid56_full_stripe_start = (u64)-1; > > > > - read_lock(&em_tree->lock); > > - em = lookup_extent_mapping(em_tree, logical, *length); > > - read_unlock(&em_tree->lock); > > - > > - if (!em) { > > - btrfs_crit(fs_info, "unable to find logical %llu len %llu", > > - logical, *length); > > - return -EINVAL; > > - } > > - > > - if (em->start > logical || em->start + em->len < logical) { > > - btrfs_crit(fs_info, > > - "found a bad mapping, wanted %Lu, found %Lu-%Lu", > > - logical, em->start, em->start + em->len); > > - free_extent_map(em); > > - return -EINVAL; > > - } > > + em = get_chunk_map(fs_info, logical, *length); > > + if (IS_ERR(em)) > > + return PTR_ERR(em); > > > > map = em->map_lookup; > > offset = logical - em->start; > > @@ -5899,8 +5861,6 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, > > u64 chunk_start, u64 physical, u64 devid, > > u64 **logical, int *naddrs, int *stripe_len) > > { > > - struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; > > - struct extent_map_tree *em_tree = &map_tree->map_tree; > > struct extent_map *em; > > struct map_lookup *map; > > u64 *buf; > > @@ -5910,24 +5870,11 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, > > u64 rmap_len; > > int i, j, nr = 0; > > > > - read_lock(&em_tree->lock); > > - em = lookup_extent_mapping(em_tree, chunk_start, 1); > > - read_unlock(&em_tree->lock); > > - > > - if (!em) { > > - btrfs_err(fs_info, "couldn't find em for chunk %Lu", > > - chunk_start); > > + em = get_chunk_map(fs_info, chunk_start, 1); > > + if (IS_ERR(em)) > > return -EIO; > > - } > > > > - if (em->start != chunk_start) { > > - btrfs_err(fs_info, "bad chunk start, em=%Lu, wanted=%Lu", > > - em->start, chunk_start); > > - free_extent_map(em); > > - return -EIO; > > - } > > map = em->map_lookup; > > - > > length = em->len; > > rmap_len = map->stripe_len; > > > > diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h > > index 24ba6bc..bd5f6cd 100644 > > --- a/fs/btrfs/volumes.h > > +++ b/fs/btrfs/volumes.h > > @@ -475,7 +475,7 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info, > > void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info, > > struct btrfs_device *tgtdev); > > void btrfs_scratch_superblocks(struct block_device *bdev, char *device_path); > > -int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree, > > +int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info, > > u64 logical, u64 len, int mirror_num); > > unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info, > > struct btrfs_mapping_tree *map_tree, > > > >