| Message ID | 1404382933-26672-9-git-send-email-miaox@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Thu, Jul 03, 2014 at 06:22:13PM +0800, Miao Xie wrote: > If we mounted a seed filesystem with degraded option, and then added a new > device into the seed filesystem, then we found adding device failed because > of the IO failure. > > Steps to reproduce: > # mkfs.btrfs -d raid1 -m raid1 <dev0> <dev1> > # btrfstune -S 1 <dev0> > # mount <dev0> -o degraded <mnt> > # btrfs device add -f <dev2> <mnt> > > It is because the original didn't set the chunk on the seed device to be > read-only if the degraded flag was set. It was introduced by patch f48b90756, > which fixed the problem the raid1 filesystem became read-only after one device > of it was missing. But this fix method was not right, we should set the read-only > flag according to the number of the missing devices, not the degraded mount > option, if the number of the missing devices is less than the max error number > that the profile of the chunk tolerates, we don't set it to be read-only. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> -liubo > > Cc: Josef Bacik <jbacik@fb.com> > Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> > --- > fs/btrfs/volumes.c | 52 ++++++++++++++++++++++++++++++++++++---------------- > 1 file changed, 36 insertions(+), 16 deletions(-) > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 73a82e5..daecfa5 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -4584,12 +4584,31 @@ out: > return ret; > } > > +static inline int btrfs_chunk_max_errors(struct map_lookup *map) > +{ > + int max_errors; > + > + if (map->type & (BTRFS_BLOCK_GROUP_RAID1 | > + BTRFS_BLOCK_GROUP_RAID10 | > + BTRFS_BLOCK_GROUP_RAID5 | > + BTRFS_BLOCK_GROUP_DUP)) { > + max_errors = 1; > + } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) { > + max_errors = 2; > + } else { > + max_errors = 0; > + } > + > + return max_errors; > +} > + > int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset) > { > struct extent_map *em; > struct map_lookup *map; > struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree; > int readonly = 0; > + int miss_ndevs = 0; > int i; > > read_lock(&map_tree->map_tree.lock); > @@ -4598,18 +4617,27 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset) > if (!em) > return 1; > > - if (btrfs_test_opt(root, DEGRADED)) { > - free_extent_map(em); > - return 0; > - } > - > map = (struct map_lookup *)em->bdev; > for (i = 0; i < map->num_stripes; i++) { > + if (map->stripes[i].dev->missing) { > + miss_ndevs++; > + continue; > + } > + > if (!map->stripes[i].dev->writeable) { > readonly = 1; > - break; > + goto end; > } > } > + > + /* > + * If the number of missing devices is larger than max errors, > + * we can not write the data into that chunk successfully, so > + * set it readonly. > + */ > + if (miss_ndevs > btrfs_chunk_max_errors(map)) > + readonly = 1; > +end: > free_extent_map(em); > return readonly; > } > @@ -5220,16 +5248,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, > } > } > > - if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) { > - if (map->type & (BTRFS_BLOCK_GROUP_RAID1 | > - BTRFS_BLOCK_GROUP_RAID10 | > - BTRFS_BLOCK_GROUP_RAID5 | > - BTRFS_BLOCK_GROUP_DUP)) { > - max_errors = 1; > - } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) { > - max_errors = 2; > - } > - } > + if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) > + max_errors = btrfs_chunk_max_errors(map); > > if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) && > dev_replace->tgtdev != NULL) { > -- > 1.9.3 > > -- > 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 73a82e5..daecfa5 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4584,12 +4584,31 @@ out: return ret; } +static inline int btrfs_chunk_max_errors(struct map_lookup *map) +{ + int max_errors; + + if (map->type & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10 | + BTRFS_BLOCK_GROUP_RAID5 | + BTRFS_BLOCK_GROUP_DUP)) { + max_errors = 1; + } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) { + max_errors = 2; + } else { + max_errors = 0; + } + + return max_errors; +} + int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset) { struct extent_map *em; struct map_lookup *map; struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree; int readonly = 0; + int miss_ndevs = 0; int i; read_lock(&map_tree->map_tree.lock); @@ -4598,18 +4617,27 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset) if (!em) return 1; - if (btrfs_test_opt(root, DEGRADED)) { - free_extent_map(em); - return 0; - } - map = (struct map_lookup *)em->bdev; for (i = 0; i < map->num_stripes; i++) { + if (map->stripes[i].dev->missing) { + miss_ndevs++; + continue; + } + if (!map->stripes[i].dev->writeable) { readonly = 1; - break; + goto end; } } + + /* + * If the number of missing devices is larger than max errors, + * we can not write the data into that chunk successfully, so + * set it readonly. + */ + if (miss_ndevs > btrfs_chunk_max_errors(map)) + readonly = 1; +end: free_extent_map(em); return readonly; } @@ -5220,16 +5248,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, } } - if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) { - if (map->type & (BTRFS_BLOCK_GROUP_RAID1 | - BTRFS_BLOCK_GROUP_RAID10 | - BTRFS_BLOCK_GROUP_RAID5 | - BTRFS_BLOCK_GROUP_DUP)) { - max_errors = 1; - } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) { - max_errors = 2; - } - } + if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) + max_errors = btrfs_chunk_max_errors(map); if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) && dev_replace->tgtdev != NULL) {
If we mounted a seed filesystem with degraded option, and then added a new device into the seed filesystem, then we found adding device failed because of the IO failure. Steps to reproduce: # mkfs.btrfs -d raid1 -m raid1 <dev0> <dev1> # btrfstune -S 1 <dev0> # mount <dev0> -o degraded <mnt> # btrfs device add -f <dev2> <mnt> It is because the original didn't set the chunk on the seed device to be read-only if the degraded flag was set. It was introduced by patch f48b90756, which fixed the problem the raid1 filesystem became read-only after one device of it was missing. But this fix method was not right, we should set the read-only flag according to the number of the missing devices, not the degraded mount option, if the number of the missing devices is less than the max error number that the profile of the chunk tolerates, we don't set it to be read-only. Cc: Josef Bacik <jbacik@fb.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> --- fs/btrfs/volumes.c | 52 ++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 36 insertions(+), 16 deletions(-)