diff options
Diffstat (limited to 'fs/namespace.c')
| -rw-r--r-- | fs/namespace.c | 161 |
1 files changed, 154 insertions, 7 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index d26f5e6d2ca3..206fc54feeba 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3901,7 +3901,7 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns, bool a } new_ns->ns.ops = &mntns_operations; if (!anon) - new_ns->seq = atomic64_add_return(1, &mnt_ns_seq); + new_ns->seq = atomic64_inc_return(&mnt_ns_seq); refcount_set(&new_ns->ns.count, 1); refcount_set(&new_ns->passive, 1); new_ns->mounts = RB_ROOT; @@ -5006,6 +5006,40 @@ static int statmount_fs_type(struct kstatmount *s, struct seq_file *seq) return 0; } +static void statmount_fs_subtype(struct kstatmount *s, struct seq_file *seq) +{ + struct super_block *sb = s->mnt->mnt_sb; + + if (sb->s_subtype) + seq_puts(seq, sb->s_subtype); +} + +static int statmount_sb_source(struct kstatmount *s, struct seq_file *seq) +{ + struct super_block *sb = s->mnt->mnt_sb; + struct mount *r = real_mount(s->mnt); + + if (sb->s_op->show_devname) { + size_t start = seq->count; + int ret; + + ret = sb->s_op->show_devname(seq, s->mnt->mnt_root); + if (ret) + return ret; + + if (unlikely(seq_has_overflowed(seq))) + return -EAGAIN; + + /* Unescape the result */ + seq->buf[seq->count] = '\0'; + seq->count = start; + seq_commit(seq, string_unescape_inplace(seq->buf + start, UNESCAPE_OCTAL)); + } else if (r->mnt_devname) { + seq_puts(seq, r->mnt_devname); + } + return 0; +} + static void statmount_mnt_ns_id(struct kstatmount *s, struct mnt_namespace *ns) { s->sm.mask |= STATMOUNT_MNT_NS_ID; @@ -5040,35 +5074,134 @@ static int statmount_mnt_opts(struct kstatmount *s, struct seq_file *seq) return 0; } +static inline int statmount_opt_unescape(struct seq_file *seq, char *buf_start) +{ + char *buf_end, *opt_start, *opt_end; + int count = 0; + + buf_end = seq->buf + seq->count; + *buf_end = '\0'; + for (opt_start = buf_start + 1; opt_start < buf_end; opt_start = opt_end + 1) { + opt_end = strchrnul(opt_start, ','); + *opt_end = '\0'; + buf_start += string_unescape(opt_start, buf_start, 0, UNESCAPE_OCTAL) + 1; + if (WARN_ON_ONCE(++count == INT_MAX)) + return -EOVERFLOW; + } + seq->count = buf_start - 1 - seq->buf; + return count; +} + +static int statmount_opt_array(struct kstatmount *s, struct seq_file *seq) +{ + struct vfsmount *mnt = s->mnt; + struct super_block *sb = mnt->mnt_sb; + size_t start = seq->count; + char *buf_start; + int err; + + if (!sb->s_op->show_options) + return 0; + + buf_start = seq->buf + start; + err = sb->s_op->show_options(seq, mnt->mnt_root); + if (err) + return err; + + if (unlikely(seq_has_overflowed(seq))) + return -EAGAIN; + + if (seq->count == start) + return 0; + + err = statmount_opt_unescape(seq, buf_start); + if (err < 0) + return err; + + s->sm.opt_num = err; + return 0; +} + +static int statmount_opt_sec_array(struct kstatmount *s, struct seq_file *seq) +{ + struct vfsmount *mnt = s->mnt; + struct super_block *sb = mnt->mnt_sb; + size_t start = seq->count; + char *buf_start; + int err; + + buf_start = seq->buf + start; + + err = security_sb_show_options(seq, sb); + if (!err) + return err; + + if (unlikely(seq_has_overflowed(seq))) + return -EAGAIN; + + if (seq->count == start) + return 0; + + err = statmount_opt_unescape(seq, buf_start); + if (err < 0) + return err; + + s->sm.opt_sec_num = err; + return 0; +} + static int statmount_string(struct kstatmount *s, u64 flag) { - int ret; + int ret = 0; size_t kbufsize; struct seq_file *seq = &s->seq; struct statmount *sm = &s->sm; + u32 start = seq->count; switch (flag) { case STATMOUNT_FS_TYPE: - sm->fs_type = seq->count; + sm->fs_type = start; ret = statmount_fs_type(s, seq); break; case STATMOUNT_MNT_ROOT: - sm->mnt_root = seq->count; + sm->mnt_root = start; ret = statmount_mnt_root(s, seq); break; case STATMOUNT_MNT_POINT: - sm->mnt_point = seq->count; + sm->mnt_point = start; ret = statmount_mnt_point(s, seq); break; case STATMOUNT_MNT_OPTS: - sm->mnt_opts = seq->count; + sm->mnt_opts = start; ret = statmount_mnt_opts(s, seq); break; + case STATMOUNT_OPT_ARRAY: + sm->opt_array = start; + ret = statmount_opt_array(s, seq); + break; + case STATMOUNT_OPT_SEC_ARRAY: + sm->opt_sec_array = start; + ret = statmount_opt_sec_array(s, seq); + break; + case STATMOUNT_FS_SUBTYPE: + sm->fs_subtype = start; + statmount_fs_subtype(s, seq); + break; + case STATMOUNT_SB_SOURCE: + sm->sb_source = start; + ret = statmount_sb_source(s, seq); + break; default: WARN_ON_ONCE(true); return -EINVAL; } + /* + * If nothing was emitted, return to avoid setting the flag + * and terminating the buffer. + */ + if (seq->count == start) + return ret; if (unlikely(check_add_overflow(sizeof(*sm), seq->count, &kbufsize))) return -EOVERFLOW; if (kbufsize >= s->bufsize) @@ -5203,6 +5336,18 @@ static int do_statmount(struct kstatmount *s, u64 mnt_id, u64 mnt_ns_id, if (!err && s->mask & STATMOUNT_MNT_OPTS) err = statmount_string(s, STATMOUNT_MNT_OPTS); + if (!err && s->mask & STATMOUNT_OPT_ARRAY) + err = statmount_string(s, STATMOUNT_OPT_ARRAY); + + if (!err && s->mask & STATMOUNT_OPT_SEC_ARRAY) + err = statmount_string(s, STATMOUNT_OPT_SEC_ARRAY); + + if (!err && s->mask & STATMOUNT_FS_SUBTYPE) + err = statmount_string(s, STATMOUNT_FS_SUBTYPE); + + if (!err && s->mask & STATMOUNT_SB_SOURCE) + err = statmount_string(s, STATMOUNT_SB_SOURCE); + if (!err && s->mask & STATMOUNT_MNT_NS_ID) statmount_mnt_ns_id(s, ns); @@ -5224,7 +5369,9 @@ static inline bool retry_statmount(const long ret, size_t *seq_size) } #define STATMOUNT_STRING_REQ (STATMOUNT_MNT_ROOT | STATMOUNT_MNT_POINT | \ - STATMOUNT_FS_TYPE | STATMOUNT_MNT_OPTS) + STATMOUNT_FS_TYPE | STATMOUNT_MNT_OPTS | \ + STATMOUNT_FS_SUBTYPE | STATMOUNT_SB_SOURCE | \ + STATMOUNT_OPT_ARRAY | STATMOUNT_OPT_SEC_ARRAY) static int prepare_kstatmount(struct kstatmount *ks, struct mnt_id_req *kreq, struct statmount __user *buf, size_t bufsize, |