diff options
| -rw-r--r-- | fs/btrfs/sysfs.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 963d63219814..43368db05968 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -21,6 +21,7 @@ #include "space-info.h" #include "block-group.h" #include "qgroup.h" +#include "misc.h" /* * Structure name Path @@ -92,6 +93,7 @@ static struct btrfs_feature_attr btrfs_attr_features_##_name = { \ static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj); static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj); +static struct kobject *get_btrfs_kobj(struct kobject *kobj); static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a) { @@ -709,6 +711,66 @@ static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \ } \ BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field) +static ssize_t btrfs_chunk_size_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + struct btrfs_space_info *sinfo = to_space_info(kobj); + + return sysfs_emit(buf, "%llu\n", READ_ONCE(sinfo->chunk_size)); +} + +/* + * Store new chunk size in space info. Can be called on a read-only filesystem. + * + * If the new chunk size value is larger than 10% of free space it is reduced + * to match that limit. Alignment must be to 256M and the system chunk size + * cannot be set. + */ +static ssize_t btrfs_chunk_size_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t len) +{ + struct btrfs_space_info *space_info = to_space_info(kobj); + struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj)); + char *retptr; + u64 val; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (!fs_info->fs_devices) + return -EINVAL; + + if (btrfs_is_zoned(fs_info)) + return -EINVAL; + + /* System block type must not be changed. */ + if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM) + return -EPERM; + + val = memparse(buf, &retptr); + /* There could be trailing '\n', also catch any typos after the value */ + retptr = skip_spaces(retptr); + if (*retptr != 0 || val == 0) + return -EINVAL; + + val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE); + + /* Limit stripe size to 10% of available space. */ + val = min(div_factor(fs_info->fs_devices->total_rw_bytes, 1), val); + + /* Must be multiple of 256M. */ + val &= ~((u64)SZ_256M - 1); + + /* Must be at least 256M. */ + if (val < SZ_256M) + return -EINVAL; + + btrfs_update_space_info_chunk_size(space_info, val); + + return len; +} + SPACE_INFO_ATTR(flags); SPACE_INFO_ATTR(total_bytes); SPACE_INFO_ATTR(bytes_used); @@ -719,6 +781,7 @@ SPACE_INFO_ATTR(bytes_readonly); SPACE_INFO_ATTR(bytes_zone_unusable); SPACE_INFO_ATTR(disk_used); SPACE_INFO_ATTR(disk_total); +BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store); static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj, struct kobj_attribute *a, @@ -773,6 +836,7 @@ static struct attribute *space_info_attrs[] = { BTRFS_ATTR_PTR(space_info, disk_used), BTRFS_ATTR_PTR(space_info, disk_total), BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold), + BTRFS_ATTR_PTR(space_info, chunk_size), NULL, }; ATTRIBUTE_GROUPS(space_info); @@ -1140,6 +1204,16 @@ static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj) return to_fs_devs(kobj)->fs_info; } +static struct kobject *get_btrfs_kobj(struct kobject *kobj) +{ + while (kobj) { + if (kobj->ktype == &btrfs_ktype) + return kobj; + kobj = kobj->parent; + } + return NULL; +} + #define NUM_FEATURE_BITS 64 #define BTRFS_FEATURE_NAME_MAX 13 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX]; |