| Message ID | 1460470563-752-2-git-send-email-anand.jain@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Apr 12, 2016 at 10:15:51PM +0800, Anand Jain wrote: > From: Qu Wenruo <quwenruo@cn.fujitsu.com> > > Introduce a new function, btrfs_check_degradable(), to judge if all chunks > in btrfs is OK for degraded mount. > > It provides the new basis for accurate btrfs mount/remount and even > runtime degraded mount check other than old one-size-fit-all method. > > Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> > --- > fs/btrfs/volumes.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > fs/btrfs/volumes.h | 1 + > 2 files changed, 64 insertions(+) > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 9d72dabdddfc..a351c5dd9e9b 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -7039,3 +7039,66 @@ static void btrfs_close_one_device(struct btrfs_device *device) > > call_rcu(&device->rcu, free_device); > } > + > +/* > + * Check if all chunks in the fs is OK for degraded mount > + * Caller itself should do extra check if DEGRADED mount option is given > + * for >0 return value. > + * > + * Return 0 if all chunks are OK. > + * Return >0 if all chunks are degradable but not all OK. > + * Return <0 if any chunk is not degradable or other bug. > + */ > +int btrfs_check_degradable(struct btrfs_fs_info *fs_info, unsigned flags) > +{ > + struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; > + struct extent_map *em; > + u64 next_start = 0; > + int ret = 0; > + > + if (flags & MS_RDONLY) > + return 0; > + > + read_lock(&map_tree->map_tree.lock); > + em = lookup_extent_mapping(&map_tree->map_tree, 0, (u64)(-1)); > + /* No any chunk? Should be a huge bug */ > + if (!em) { > + ret = -ENOENT; > + goto out; > + } > + > + while (em) { > + struct map_lookup *map; > + int missing = 0; > + int max_tolerated; > + int i; > + > + map = (struct map_lookup *) em->bdev; > + max_tolerated = > + btrfs_get_num_tolerated_disk_barrier_failures( > + map->type); > + for (i = 0; i < map->num_stripes; i++) { > + if (map->stripes[i].dev->missing) > + missing++; > + } > + if (missing > max_tolerated) { > + ret = -EIO; > + btrfs_warn(fs_info, > + "missing devices(%d) exceeds the limit(%d), writebale mount is not allowed", > + missing, max_tolerated); Typo: s/writebale/writeable/
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 9d72dabdddfc..a351c5dd9e9b 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -7039,3 +7039,66 @@ static void btrfs_close_one_device(struct btrfs_device *device) call_rcu(&device->rcu, free_device); } + +/* + * Check if all chunks in the fs is OK for degraded mount + * Caller itself should do extra check if DEGRADED mount option is given + * for >0 return value. + * + * Return 0 if all chunks are OK. + * Return >0 if all chunks are degradable but not all OK. + * Return <0 if any chunk is not degradable or other bug. + */ +int btrfs_check_degradable(struct btrfs_fs_info *fs_info, unsigned flags) +{ + struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; + struct extent_map *em; + u64 next_start = 0; + int ret = 0; + + if (flags & MS_RDONLY) + return 0; + + read_lock(&map_tree->map_tree.lock); + em = lookup_extent_mapping(&map_tree->map_tree, 0, (u64)(-1)); + /* No any chunk? Should be a huge bug */ + if (!em) { + ret = -ENOENT; + goto out; + } + + while (em) { + struct map_lookup *map; + int missing = 0; + int max_tolerated; + int i; + + map = (struct map_lookup *) em->bdev; + max_tolerated = + btrfs_get_num_tolerated_disk_barrier_failures( + map->type); + for (i = 0; i < map->num_stripes; i++) { + if (map->stripes[i].dev->missing) + missing++; + } + if (missing > max_tolerated) { + ret = -EIO; + btrfs_warn(fs_info, + "missing devices(%d) exceeds the limit(%d), writebale mount is not allowed", + missing, max_tolerated); + goto out; + } else if (missing) + ret = 1; + next_start = extent_map_end(em); + + /* + * Alwasy search range [next_start, (u64)-1) to find the next + * chunk map + */ + em = lookup_extent_mapping(&map_tree->map_tree, next_start, + (u64)(-1) - next_start); + } +out: + read_unlock(&map_tree->map_tree.lock); + return ret; +} diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 1939ebde63df..351431a3f5aa 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -566,5 +566,6 @@ static inline void unlock_chunks(struct btrfs_root *root) struct list_head *btrfs_get_fs_uuids(void); void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info); void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info); +int btrfs_check_degradable(struct btrfs_fs_info *fs_info, unsigned flags); #endif