2 * Quota code necessary even when VFS quota support is not compiled
3 * into the kernel. The interesting stuff is over in dquot.c, here
4 * we have symbols for initial quotactl(2) handling, the sysctl(2)
5 * variables, etc - things needed even when quota support disabled.
9 #include <linux/namei.h>
10 #include <linux/slab.h>
11 #include <asm/current.h>
12 #include <linux/uaccess.h>
13 #include <linux/kernel.h>
14 #include <linux/security.h>
15 #include <linux/syscalls.h>
16 #include <linux/capability.h>
17 #include <linux/quotaops.h>
18 #include <linux/types.h>
19 #include <linux/writeback.h>
21 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
25 /* these commands do not require any special privilegues */
33 /* allow to query information for dquots we "own" */
36 if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
37 (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
41 if (!capable(CAP_SYS_ADMIN))
45 return security_quotactl(cmd, type, id, sb);
48 static void quota_sync_one(struct super_block *sb, void *arg)
50 int type = *(int *)arg;
52 if (sb->s_qcop && sb->s_qcop->quota_sync &&
53 (sb->s_quota_types & (1 << type)))
54 sb->s_qcop->quota_sync(sb, type);
57 static int quota_sync_all(int type)
61 if (type >= MAXQUOTAS)
63 ret = security_quotactl(Q_SYNC, type, 0, NULL);
65 iterate_supers(quota_sync_one, &type);
69 static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
72 if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_on_meta)
74 if (sb->s_qcop->quota_on_meta)
75 return sb->s_qcop->quota_on_meta(sb, type, id);
78 return sb->s_qcop->quota_on(sb, type, id, path);
81 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
85 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
86 if (!sb_has_quota_active(sb, type)) {
87 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
90 fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
91 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
92 if (copy_to_user(addr, &fmt, sizeof(fmt)))
97 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
99 struct if_dqinfo info;
102 if (!sb->s_qcop->get_info)
104 ret = sb->s_qcop->get_info(sb, type, &info);
105 if (!ret && copy_to_user(addr, &info, sizeof(info)))
110 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
112 struct if_dqinfo info;
114 if (copy_from_user(&info, addr, sizeof(info)))
116 if (!sb->s_qcop->set_info)
118 return sb->s_qcop->set_info(sb, type, &info);
121 static void copy_to_if_dqblk(struct if_dqblk *dst, struct fs_disk_quota *src)
123 memset(dst, 0, sizeof(*dst));
124 dst->dqb_bhardlimit = src->d_blk_hardlimit;
125 dst->dqb_bsoftlimit = src->d_blk_softlimit;
126 dst->dqb_curspace = src->d_bcount;
127 dst->dqb_ihardlimit = src->d_ino_hardlimit;
128 dst->dqb_isoftlimit = src->d_ino_softlimit;
129 dst->dqb_curinodes = src->d_icount;
130 dst->dqb_btime = src->d_btimer;
131 dst->dqb_itime = src->d_itimer;
132 dst->dqb_valid = QIF_ALL;
135 static int quota_getquota(struct super_block *sb, int type, qid_t id,
139 struct fs_disk_quota fdq;
143 if (!sb->s_qcop->get_dqblk)
145 qid = make_kqid(current_user_ns(), type, id);
148 ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
151 copy_to_if_dqblk(&idq, &fdq);
152 if (copy_to_user(addr, &idq, sizeof(idq)))
157 static void copy_from_if_dqblk(struct fs_disk_quota *dst, struct if_dqblk *src)
159 dst->d_blk_hardlimit = src->dqb_bhardlimit;
160 dst->d_blk_softlimit = src->dqb_bsoftlimit;
161 dst->d_bcount = src->dqb_curspace;
162 dst->d_ino_hardlimit = src->dqb_ihardlimit;
163 dst->d_ino_softlimit = src->dqb_isoftlimit;
164 dst->d_icount = src->dqb_curinodes;
165 dst->d_btimer = src->dqb_btime;
166 dst->d_itimer = src->dqb_itime;
168 dst->d_fieldmask = 0;
169 if (src->dqb_valid & QIF_BLIMITS)
170 dst->d_fieldmask |= FS_DQ_BSOFT | FS_DQ_BHARD;
171 if (src->dqb_valid & QIF_SPACE)
172 dst->d_fieldmask |= FS_DQ_BCOUNT;
173 if (src->dqb_valid & QIF_ILIMITS)
174 dst->d_fieldmask |= FS_DQ_ISOFT | FS_DQ_IHARD;
175 if (src->dqb_valid & QIF_INODES)
176 dst->d_fieldmask |= FS_DQ_ICOUNT;
177 if (src->dqb_valid & QIF_BTIME)
178 dst->d_fieldmask |= FS_DQ_BTIMER;
179 if (src->dqb_valid & QIF_ITIME)
180 dst->d_fieldmask |= FS_DQ_ITIMER;
183 static int quota_setquota(struct super_block *sb, int type, qid_t id,
186 struct fs_disk_quota fdq;
190 if (copy_from_user(&idq, addr, sizeof(idq)))
192 if (!sb->s_qcop->set_dqblk)
194 qid = make_kqid(current_user_ns(), type, id);
197 copy_from_if_dqblk(&fdq, &idq);
198 return sb->s_qcop->set_dqblk(sb, qid, &fdq);
201 static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr)
205 if (copy_from_user(&flags, addr, sizeof(flags)))
207 if (!sb->s_qcop->set_xstate)
209 return sb->s_qcop->set_xstate(sb, flags, cmd);
212 static int quota_getxstate(struct super_block *sb, void __user *addr)
214 struct fs_quota_stat fqs;
217 if (!sb->s_qcop->get_xstate)
219 ret = sb->s_qcop->get_xstate(sb, &fqs);
220 if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
225 static int quota_getxstatev(struct super_block *sb, void __user *addr)
227 struct fs_quota_statv fqs;
230 if (!sb->s_qcop->get_xstatev)
233 memset(&fqs, 0, sizeof(fqs));
234 if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
237 /* If this kernel doesn't support user specified version, fail */
238 switch (fqs.qs_version) {
239 case FS_QSTATV_VERSION1:
244 ret = sb->s_qcop->get_xstatev(sb, &fqs);
245 if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
250 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
253 struct fs_disk_quota fdq;
256 if (copy_from_user(&fdq, addr, sizeof(fdq)))
258 if (!sb->s_qcop->set_dqblk)
260 qid = make_kqid(current_user_ns(), type, id);
263 return sb->s_qcop->set_dqblk(sb, qid, &fdq);
266 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
269 struct fs_disk_quota fdq;
273 if (!sb->s_qcop->get_dqblk)
275 qid = make_kqid(current_user_ns(), type, id);
278 ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
279 if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
284 static int quota_rmxquota(struct super_block *sb, void __user *addr)
288 if (copy_from_user(&flags, addr, sizeof(flags)))
290 if (!sb->s_qcop->rm_xquota)
292 return sb->s_qcop->rm_xquota(sb, flags);
295 /* Copy parameters and call proper function */
296 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
297 void __user *addr, struct path *path)
301 if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
304 * Quota not supported on this fs? Check this before s_quota_types
305 * since they needn't be set if quota is not supported at all.
309 if (!(sb->s_quota_types & (1 << type)))
312 ret = check_quotactl_permission(sb, type, cmd, id);
318 return quota_quotaon(sb, type, cmd, id, path);
320 if (!sb->s_qcop->quota_off)
322 return sb->s_qcop->quota_off(sb, type);
324 return quota_getfmt(sb, type, addr);
326 return quota_getinfo(sb, type, addr);
328 return quota_setinfo(sb, type, addr);
330 return quota_getquota(sb, type, id, addr);
332 return quota_setquota(sb, type, id, addr);
334 if (!sb->s_qcop->quota_sync)
336 return sb->s_qcop->quota_sync(sb, type);
339 return quota_setxstate(sb, cmd, addr);
341 return quota_rmxquota(sb, addr);
343 return quota_getxstate(sb, addr);
345 return quota_getxstatev(sb, addr);
347 return quota_setxquota(sb, type, id, addr);
349 return quota_getxquota(sb, type, id, addr);
351 if (sb->s_flags & MS_RDONLY)
353 /* XFS quotas are fully coherent now, making this call a noop */
362 /* Return 1 if 'cmd' will block on frozen filesystem */
363 static int quotactl_cmd_write(int cmd)
378 #endif /* CONFIG_BLOCK */
381 * look up a superblock on which quota ops will be performed
382 * - use the name of a block device to find the superblock thereon
384 static struct super_block *quotactl_block(const char __user *special, int cmd)
387 struct block_device *bdev;
388 struct super_block *sb;
389 struct filename *tmp = getname(special);
392 return ERR_CAST(tmp);
393 bdev = lookup_bdev(tmp->name);
396 return ERR_CAST(bdev);
397 if (quotactl_cmd_write(cmd))
398 sb = get_super_thawed(bdev);
400 sb = get_super(bdev);
403 return ERR_PTR(-ENODEV);
407 return ERR_PTR(-ENODEV);
412 * This is the system call interface. This communicates with
413 * the user-level programs. Currently this only supports diskquota
414 * calls. Maybe we need to add the process quotas etc. in the future,
415 * but we probably should use rlimits for that.
417 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
418 qid_t, id, void __user *, addr)
421 struct super_block *sb = NULL;
422 struct path path, *pathp = NULL;
425 cmds = cmd >> SUBCMDSHIFT;
426 type = cmd & SUBCMDMASK;
429 * As a special case Q_SYNC can be called without a specific device.
430 * It will iterate all superblocks that have quota enabled and call
431 * the sync action on each of them.
435 return quota_sync_all(type);
440 * Path for quotaon has to be resolved before grabbing superblock
441 * because that gets s_umount sem which is also possibly needed by path
442 * resolution (think about autofs) and thus deadlocks could arise.
444 if (cmds == Q_QUOTAON) {
445 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
447 pathp = ERR_PTR(ret);
452 sb = quotactl_block(special, cmds);
458 ret = do_quotactl(sb, type, cmds, id, addr, pathp);
462 if (pathp && !IS_ERR(pathp))