X-Git-Url: http://git.cascardo.eti.br/?a=blobdiff_plain;f=fs%2Fbtrfs%2Fsysfs.c;h=7d340f352b7725406ca274386ebbb3e64d17c061;hb=ba631941ef09c10e229661219dbd1707e56131d8;hp=5b326cd60a4aa3c048eefe730312248d73cf47ba;hpb=0a11953851213fd1d3eebcb68b4a537d458c70c2;p=cascardo%2Flinux.git diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 5b326cd60a4a..7d340f352b77 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -22,24 +22,371 @@ #include #include #include +#include #include "ctree.h" #include "disk-io.h" #include "transaction.h" +#include "sysfs.h" + +static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj); + +static u64 get_features(struct btrfs_fs_info *fs_info, + enum btrfs_feature_set set) +{ + struct btrfs_super_block *disk_super = fs_info->super_copy; + if (set == FEAT_COMPAT) + return btrfs_super_compat_flags(disk_super); + else if (set == FEAT_COMPAT_RO) + return btrfs_super_compat_ro_flags(disk_super); + else + return btrfs_super_incompat_flags(disk_super); +} + +static void set_features(struct btrfs_fs_info *fs_info, + enum btrfs_feature_set set, u64 features) +{ + struct btrfs_super_block *disk_super = fs_info->super_copy; + if (set == FEAT_COMPAT) + btrfs_set_super_compat_flags(disk_super, features); + else if (set == FEAT_COMPAT_RO) + btrfs_set_super_compat_ro_flags(disk_super, features); + else + btrfs_set_super_incompat_flags(disk_super, features); +} + +static int can_modify_feature(struct btrfs_feature_attr *fa) +{ + int val = 0; + u64 set, clear; + switch (fa->feature_set) { + case FEAT_COMPAT: + set = BTRFS_FEATURE_COMPAT_SAFE_SET; + clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; + break; + case FEAT_COMPAT_RO: + set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET; + clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR; + break; + case FEAT_INCOMPAT: + set = BTRFS_FEATURE_INCOMPAT_SAFE_SET; + clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR; + break; + default: + BUG(); + } + + if (set & fa->feature_bit) + val |= 1; + if (clear & fa->feature_bit) + val |= 2; + + return val; +} + +static ssize_t btrfs_feature_attr_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + int val = 0; + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a); + if (fs_info) { + u64 features = get_features(fs_info, fa->feature_set); + if (features & fa->feature_bit) + val = 1; + } else + val = can_modify_feature(fa); + + return snprintf(buf, PAGE_SIZE, "%d\n", val); +} + +static ssize_t btrfs_feature_attr_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t count) +{ + struct btrfs_fs_info *fs_info; + struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a); + struct btrfs_trans_handle *trans; + u64 features, set, clear; + unsigned long val; + int ret; + + fs_info = to_fs_info(kobj); + if (!fs_info) + return -EPERM; + + ret = kstrtoul(skip_spaces(buf), 0, &val); + if (ret) + return ret; + + if (fa->feature_set == FEAT_COMPAT) { + set = BTRFS_FEATURE_COMPAT_SAFE_SET; + clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; + } else if (fa->feature_set == FEAT_COMPAT_RO) { + set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET; + clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR; + } else { + set = BTRFS_FEATURE_INCOMPAT_SAFE_SET; + clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR; + } + + features = get_features(fs_info, fa->feature_set); + + /* Nothing to do */ + if ((val && (features & fa->feature_bit)) || + (!val && !(features & fa->feature_bit))) + return count; + + if ((val && !(set & fa->feature_bit)) || + (!val && !(clear & fa->feature_bit))) { + btrfs_info(fs_info, + "%sabling feature %s on mounted fs is not supported.", + val ? "En" : "Dis", fa->kobj_attr.attr.name); + return -EPERM; + } + + btrfs_info(fs_info, "%s %s feature flag", + val ? "Setting" : "Clearing", fa->kobj_attr.attr.name); + + trans = btrfs_start_transaction(fs_info->fs_root, 1); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + spin_lock(&fs_info->super_lock); + features = get_features(fs_info, fa->feature_set); + if (val) + features |= fa->feature_bit; + else + features &= ~fa->feature_bit; + set_features(fs_info, fa->feature_set, features); + spin_unlock(&fs_info->super_lock); + + ret = btrfs_commit_transaction(trans, fs_info->fs_root); + if (ret) + return ret; + + return count; +} + +static umode_t btrfs_feature_visible(struct kobject *kobj, + struct attribute *attr, int unused) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + umode_t mode = attr->mode; + + if (fs_info) { + struct btrfs_feature_attr *fa; + u64 features; + + fa = attr_to_btrfs_feature_attr(attr); + features = get_features(fs_info, fa->feature_set); + + if (can_modify_feature(fa)) + mode |= S_IWUSR; + else if (!(features & fa->feature_bit)) + mode = 0; + } + + return mode; +} + +BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF); +BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL); +BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS); +BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO); +BTRFS_FEAT_ATTR_INCOMPAT(compress_lzov2, COMPRESS_LZOv2); +BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA); +BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF); +BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56); +BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA); + +static struct attribute *btrfs_supported_feature_attrs[] = { + BTRFS_FEAT_ATTR_PTR(mixed_backref), + BTRFS_FEAT_ATTR_PTR(default_subvol), + BTRFS_FEAT_ATTR_PTR(mixed_groups), + BTRFS_FEAT_ATTR_PTR(compress_lzo), + BTRFS_FEAT_ATTR_PTR(compress_lzov2), + BTRFS_FEAT_ATTR_PTR(big_metadata), + BTRFS_FEAT_ATTR_PTR(extended_iref), + BTRFS_FEAT_ATTR_PTR(raid56), + BTRFS_FEAT_ATTR_PTR(skinny_metadata), + NULL +}; + +static const struct attribute_group btrfs_feature_attr_group = { + .name = "features", + .is_visible = btrfs_feature_visible, + .attrs = btrfs_supported_feature_attrs, +}; + +static void btrfs_release_super_kobj(struct kobject *kobj) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + complete(&fs_info->kobj_unregister); +} + +static struct kobj_type btrfs_ktype = { + .sysfs_ops = &kobj_sysfs_ops, + .release = btrfs_release_super_kobj, +}; + +static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj) +{ + if (kobj->ktype != &btrfs_ktype) + return NULL; + return container_of(kobj, struct btrfs_fs_info, super_kobj); +} + +void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info) +{ + kobject_del(&fs_info->super_kobj); + kobject_put(&fs_info->super_kobj); + wait_for_completion(&fs_info->kobj_unregister); +} + +const char * const btrfs_feature_set_names[3] = { + [FEAT_COMPAT] = "compat", + [FEAT_COMPAT_RO] = "compat_ro", + [FEAT_INCOMPAT] = "incompat", +}; + +#define NUM_FEATURE_BITS 64 +static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13]; +static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS]; + +static void init_feature_attrs(void) +{ + struct btrfs_feature_attr *fa; + int set, i; + + BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) != + ARRAY_SIZE(btrfs_feature_attrs)); + BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) != + ARRAY_SIZE(btrfs_feature_attrs[0])); + + for (i = 0; btrfs_supported_feature_attrs[i]; i++) { + struct btrfs_feature_attr *sfa; + struct attribute *a = btrfs_supported_feature_attrs[i]; + sfa = attr_to_btrfs_feature_attr(a); + fa = &btrfs_feature_attrs[sfa->feature_set][sfa->feature_bit]; + + fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name; + } + + for (set = 0; set < FEAT_MAX; set++) { + for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { + char *name = btrfs_unknown_feature_names[set][i]; + fa = &btrfs_feature_attrs[set][i]; + + if (fa->kobj_attr.attr.name) + continue; + + snprintf(name, 13, "%s:%u", + btrfs_feature_set_names[set], i); + + fa->kobj_attr.attr.name = name; + fa->kobj_attr.attr.mode = S_IRUGO; + fa->feature_set = set; + fa->feature_bit = 1ULL << i; + } + } +} + +static u64 supported_feature_masks[3] = { + [FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP, + [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP, + [FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP, +}; + +static int add_unknown_feature_attrs(struct btrfs_fs_info *fs_info) +{ + int set; + + for (set = 0; set < FEAT_MAX; set++) { + int i, count, ret, index = 0; + struct attribute **attrs; + struct attribute_group agroup = { + .name = "features", + }; + u64 features = get_features(fs_info, set); + features &= ~supported_feature_masks[set]; + + count = hweight64(features); + + if (!count) + continue; + + attrs = kcalloc(count + 1, sizeof(void *), GFP_KERNEL); + + for (i = 0; i < NUM_FEATURE_BITS; i++) { + struct btrfs_feature_attr *fa; + + if (!(features & (1ULL << i))) + continue; + + fa = &btrfs_feature_attrs[set][i]; + attrs[index++] = &fa->kobj_attr.attr; + } + + attrs[index] = NULL; + agroup.attrs = attrs; + + ret = sysfs_merge_group(&fs_info->super_kobj, &agroup); + kfree(attrs); + if (ret) + return ret; + } + return 0; +} /* /sys/fs/btrfs/ entry */ static struct kset *btrfs_kset; +int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info) +{ + int error; + + init_completion(&fs_info->kobj_unregister); + fs_info->super_kobj.kset = btrfs_kset; + error = kobject_init_and_add(&fs_info->super_kobj, &btrfs_ktype, NULL, + "%pU", fs_info->fsid); + + error = sysfs_create_group(&fs_info->super_kobj, + &btrfs_feature_attr_group); + if (error) + goto failure; + + error = add_unknown_feature_attrs(fs_info); + if (error) + goto failure; + + return 0; +failure: + btrfs_sysfs_remove_one(fs_info); + return error; +} + int btrfs_init_sysfs(void) { + int ret; btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj); if (!btrfs_kset) return -ENOMEM; + + init_feature_attrs(); + + ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); + if (ret) { + kset_unregister(btrfs_kset); + return ret; + } + return 0; } void btrfs_exit_sysfs(void) { + sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); kset_unregister(btrfs_kset); }