diff options
| -rw-r--r-- | fs/quota/Makefile | 2 | ||||
| -rw-r--r-- | fs/quota/kqid.c | 132 | ||||
| -rw-r--r-- | include/linux/quota.h | 125 |
3 files changed, 258 insertions, 1 deletions
diff --git a/fs/quota/Makefile b/fs/quota/Makefile index 5f9e9e276af0..c66c37cdaa39 100644 --- a/fs/quota/Makefile +++ b/fs/quota/Makefile @@ -2,6 +2,6 @@ obj-$(CONFIG_QUOTA) += dquot.o obj-$(CONFIG_QFMT_V1) += quota_v1.o obj-$(CONFIG_QFMT_V2) += quota_v2.o obj-$(CONFIG_QUOTA_TREE) += quota_tree.o -obj-$(CONFIG_QUOTACTL) += quota.o +obj-$(CONFIG_QUOTACTL) += quota.o kqid.o obj-$(CONFIG_QUOTACTL_COMPAT) += compat.o obj-$(CONFIG_QUOTA_NETLINK_INTERFACE) += netlink.o diff --git a/fs/quota/kqid.c b/fs/quota/kqid.c new file mode 100644 index 000000000000..2f97b0e2c501 --- /dev/null +++ b/fs/quota/kqid.c @@ -0,0 +1,132 @@ +#include <linux/fs.h> +#include <linux/quota.h> +#include <linux/export.h> + +/** + * qid_eq - Test to see if to kquid values are the same + * @left: A qid value + * @right: Another quid value + * + * Return true if the two qid values are equal and false otherwise. + */ +bool qid_eq(struct kqid left, struct kqid right) +{ + if (left.type != right.type) + return false; + switch(left.type) { + case USRQUOTA: + return uid_eq(left.uid, right.uid); + case GRPQUOTA: + return gid_eq(left.gid, right.gid); + case PRJQUOTA: + return projid_eq(left.projid, right.projid); + default: + BUG(); + } +} +EXPORT_SYMBOL(qid_eq); + +/** + * qid_lt - Test to see if one qid value is less than another + * @left: The possibly lesser qid value + * @right: The possibly greater qid value + * + * Return true if left is less than right and false otherwise. + */ +bool qid_lt(struct kqid left, struct kqid right) +{ + if (left.type < right.type) + return true; + if (left.type > right.type) + return false; + switch (left.type) { + case USRQUOTA: + return uid_lt(left.uid, right.uid); + case GRPQUOTA: + return gid_lt(left.gid, right.gid); + case PRJQUOTA: + return projid_lt(left.projid, right.projid); + default: + BUG(); + } +} +EXPORT_SYMBOL(qid_lt); + +/** + * from_kqid - Create a qid from a kqid user-namespace pair. + * @targ: The user namespace we want a qid in. + * @kuid: The kernel internal quota identifier to start with. + * + * Map @kqid into the user-namespace specified by @targ and + * return the resulting qid. + * + * There is always a mapping into the initial user_namespace. + * + * If @kqid has no mapping in @targ (qid_t)-1 is returned. + */ +qid_t from_kqid(struct user_namespace *targ, struct kqid kqid) +{ + switch (kqid.type) { + case USRQUOTA: + return from_kuid(targ, kqid.uid); + case GRPQUOTA: + return from_kgid(targ, kqid.gid); + case PRJQUOTA: + return from_kprojid(targ, kqid.projid); + default: + BUG(); + } +} +EXPORT_SYMBOL(from_kqid); + +/** + * from_kqid_munged - Create a qid from a kqid user-namespace pair. + * @targ: The user namespace we want a qid in. + * @kqid: The kernel internal quota identifier to start with. + * + * Map @kqid into the user-namespace specified by @targ and + * return the resulting qid. + * + * There is always a mapping into the initial user_namespace. + * + * Unlike from_kqid from_kqid_munged never fails and always + * returns a valid projid. This makes from_kqid_munged + * appropriate for use in places where failing to provide + * a qid_t is not a good option. + * + * If @kqid has no mapping in @targ the kqid.type specific + * overflow identifier is returned. + */ +qid_t from_kqid_munged(struct user_namespace *targ, struct kqid kqid) +{ + switch (kqid.type) { + case USRQUOTA: + return from_kuid_munged(targ, kqid.uid); + case GRPQUOTA: + return from_kgid_munged(targ, kqid.gid); + case PRJQUOTA: + return from_kprojid_munged(targ, kqid.projid); + default: + BUG(); + } +} +EXPORT_SYMBOL(from_kqid_munged); + +/** + * qid_valid - Report if a valid value is stored in a kqid. + * @qid: The kernel internal quota identifier to test. + */ +bool qid_valid(struct kqid qid) +{ + switch (qid.type) { + case USRQUOTA: + return uid_valid(qid.uid); + case GRPQUOTA: + return gid_valid(qid.gid); + case PRJQUOTA: + return projid_valid(qid.projid); + default: + BUG(); + } +} +EXPORT_SYMBOL(qid_valid); diff --git a/include/linux/quota.h b/include/linux/quota.h index 524ede8a160a..00ac8d846c14 100644 --- a/include/linux/quota.h +++ b/include/linux/quota.h @@ -181,10 +181,135 @@ enum { #include <linux/dqblk_v2.h> #include <linux/atomic.h> +#include <linux/uidgid.h> +#include <linux/projid.h> + +#undef USRQUOTA +#undef GRPQUOTA +enum quota_type { + USRQUOTA = 0, /* element used for user quotas */ + GRPQUOTA = 1, /* element used for group quotas */ + PRJQUOTA = 2, /* element used for project quotas */ +}; typedef __kernel_uid32_t qid_t; /* Type in which we store ids in memory */ typedef long long qsize_t; /* Type in which we store sizes */ +struct kqid { /* Type in which we store the quota identifier */ + union { + kuid_t uid; + kgid_t gid; + kprojid_t projid; + }; + enum quota_type type; /* USRQUOTA (uid) or GRPQUOTA (gid) or PRJQUOTA (projid) */ +}; + +extern bool qid_eq(struct kqid left, struct kqid right); +extern bool qid_lt(struct kqid left, struct kqid right); +extern qid_t from_kqid(struct user_namespace *to, struct kqid qid); +extern qid_t from_kqid_munged(struct user_namespace *to, struct kqid qid); +extern bool qid_valid(struct kqid qid); + +/** + * make_kqid - Map a user-namespace, type, qid tuple into a kqid. + * @from: User namespace that the qid is in + * @type: The type of quota + * @qid: Quota identifier + * + * Maps a user-namespace, type qid tuple into a kernel internal + * kqid, and returns that kqid. + * + * When there is no mapping defined for the user-namespace, type, + * qid tuple an invalid kqid is returned. Callers are expected to + * test for and handle handle invalid kqids being returned. + * Invalid kqids may be tested for using qid_valid(). + */ +static inline struct kqid make_kqid(struct user_namespace *from, + enum quota_type type, qid_t qid) +{ + struct kqid kqid; + + kqid.type = type; + switch (type) { + case USRQUOTA: + kqid.uid = make_kuid(from, qid); + break; + case GRPQUOTA: + kqid.gid = make_kgid(from, qid); + break; + case PRJQUOTA: + kqid.projid = make_kprojid(from, qid); + break; + default: + BUG(); + } + return kqid; +} + +/** + * make_kqid_invalid - Explicitly make an invalid kqid + * @type: The type of quota identifier + * + * Returns an invalid kqid with the specified type. + */ +static inline struct kqid make_kqid_invalid(enum quota_type type) +{ + struct kqid kqid; + + kqid.type = type; + switch (type) { + case USRQUOTA: + kqid.uid = INVALID_UID; + break; + case GRPQUOTA: + kqid.gid = INVALID_GID; + break; + case PRJQUOTA: + kqid.projid = INVALID_PROJID; + break; + default: + BUG(); + } + return kqid; +} + +/** + * make_kqid_uid - Make a kqid from a kuid + * @uid: The kuid to make the quota identifier from + */ +static inline struct kqid make_kqid_uid(kuid_t uid) +{ + struct kqid kqid; + kqid.type = USRQUOTA; + kqid.uid = uid; + return kqid; +} + +/** + * make_kqid_gid - Make a kqid from a kgid + * @gid: The kgid to make the quota identifier from + */ +static inline struct kqid make_kqid_gid(kgid_t gid) +{ + struct kqid kqid; + kqid.type = GRPQUOTA; + kqid.gid = gid; + return kqid; +} + +/** + * make_kqid_projid - Make a kqid from a projid + * @projid: The kprojid to make the quota identifier from + */ +static inline struct kqid make_kqid_projid(kprojid_t projid) +{ + struct kqid kqid; + kqid.type = PRJQUOTA; + kqid.projid = projid; + return kqid; +} + + extern spinlock_t dq_data_lock; /* Maximal numbers of writes for quota operation (insert/delete/update) |