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 if (sb->s_qcop && sb->s_qcop->quota_sync)
51 sb->s_qcop->quota_sync(sb, *(int *)arg);
54 static int quota_sync_all(int type)
58 if (type >= MAXQUOTAS)
60 ret = security_quotactl(Q_SYNC, type, 0, NULL);
62 iterate_supers(quota_sync_one, &type);
66 static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
69 if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_on_meta)
71 if (sb->s_qcop->quota_on_meta)
72 return sb->s_qcop->quota_on_meta(sb, type, id);
75 return sb->s_qcop->quota_on(sb, type, id, path);
78 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
82 down_read(&sb_dqopt(sb)->dqptr_sem);
83 if (!sb_has_quota_active(sb, type)) {
84 up_read(&sb_dqopt(sb)->dqptr_sem);
87 fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
88 up_read(&sb_dqopt(sb)->dqptr_sem);
89 if (copy_to_user(addr, &fmt, sizeof(fmt)))
94 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
96 struct if_dqinfo info;
99 if (!sb->s_qcop->get_info)
101 ret = sb->s_qcop->get_info(sb, type, &info);
102 if (!ret && copy_to_user(addr, &info, sizeof(info)))
107 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
109 struct if_dqinfo info;
111 if (copy_from_user(&info, addr, sizeof(info)))
113 if (!sb->s_qcop->set_info)
115 return sb->s_qcop->set_info(sb, type, &info);
118 static void copy_to_if_dqblk(struct if_dqblk *dst, struct fs_disk_quota *src)
120 dst->dqb_bhardlimit = src->d_blk_hardlimit;
121 dst->dqb_bsoftlimit = src->d_blk_softlimit;
122 dst->dqb_curspace = src->d_bcount;
123 dst->dqb_ihardlimit = src->d_ino_hardlimit;
124 dst->dqb_isoftlimit = src->d_ino_softlimit;
125 dst->dqb_curinodes = src->d_icount;
126 dst->dqb_btime = src->d_btimer;
127 dst->dqb_itime = src->d_itimer;
128 dst->dqb_valid = QIF_ALL;
131 static int quota_getquota(struct super_block *sb, int type, qid_t id,
135 struct fs_disk_quota fdq;
139 if (!sb->s_qcop->get_dqblk)
141 qid = make_kqid(current_user_ns(), type, id);
144 ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
147 copy_to_if_dqblk(&idq, &fdq);
148 if (copy_to_user(addr, &idq, sizeof(idq)))
153 static void copy_from_if_dqblk(struct fs_disk_quota *dst, struct if_dqblk *src)
155 dst->d_blk_hardlimit = src->dqb_bhardlimit;
156 dst->d_blk_softlimit = src->dqb_bsoftlimit;
157 dst->d_bcount = src->dqb_curspace;
158 dst->d_ino_hardlimit = src->dqb_ihardlimit;
159 dst->d_ino_softlimit = src->dqb_isoftlimit;
160 dst->d_icount = src->dqb_curinodes;
161 dst->d_btimer = src->dqb_btime;
162 dst->d_itimer = src->dqb_itime;
164 dst->d_fieldmask = 0;
165 if (src->dqb_valid & QIF_BLIMITS)
166 dst->d_fieldmask |= FS_DQ_BSOFT | FS_DQ_BHARD;
167 if (src->dqb_valid & QIF_SPACE)
168 dst->d_fieldmask |= FS_DQ_BCOUNT;
169 if (src->dqb_valid & QIF_ILIMITS)
170 dst->d_fieldmask |= FS_DQ_ISOFT | FS_DQ_IHARD;
171 if (src->dqb_valid & QIF_INODES)
172 dst->d_fieldmask |= FS_DQ_ICOUNT;
173 if (src->dqb_valid & QIF_BTIME)
174 dst->d_fieldmask |= FS_DQ_BTIMER;
175 if (src->dqb_valid & QIF_ITIME)
176 dst->d_fieldmask |= FS_DQ_ITIMER;
179 static int quota_setquota(struct super_block *sb, int type, qid_t id,
182 struct fs_disk_quota fdq;
186 if (copy_from_user(&idq, addr, sizeof(idq)))
188 if (!sb->s_qcop->set_dqblk)
190 qid = make_kqid(current_user_ns(), type, id);
193 copy_from_if_dqblk(&fdq, &idq);
194 return sb->s_qcop->set_dqblk(sb, qid, &fdq);
197 static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr)
201 if (copy_from_user(&flags, addr, sizeof(flags)))
203 if (!sb->s_qcop->set_xstate)
205 return sb->s_qcop->set_xstate(sb, flags, cmd);
208 static int quota_getxstate(struct super_block *sb, void __user *addr)
210 struct fs_quota_stat fqs;
213 if (!sb->s_qcop->get_xstate)
215 ret = sb->s_qcop->get_xstate(sb, &fqs);
216 if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
221 static int quota_getxstatev(struct super_block *sb, void __user *addr)
223 struct fs_quota_statv fqs;
226 if (!sb->s_qcop->get_xstatev)
229 memset(&fqs, 0, sizeof(fqs));
230 if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
233 /* If this kernel doesn't support user specified version, fail */
234 switch (fqs.qs_version) {
235 case FS_QSTATV_VERSION1:
240 ret = sb->s_qcop->get_xstatev(sb, &fqs);
241 if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
246 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
249 struct fs_disk_quota fdq;
252 if (copy_from_user(&fdq, addr, sizeof(fdq)))
254 if (!sb->s_qcop->set_dqblk)
256 qid = make_kqid(current_user_ns(), type, id);
259 return sb->s_qcop->set_dqblk(sb, qid, &fdq);
262 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
265 struct fs_disk_quota fdq;
269 if (!sb->s_qcop->get_dqblk)
271 qid = make_kqid(current_user_ns(), type, id);
274 ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
275 if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
280 /* Copy parameters and call proper function */
281 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
282 void __user *addr, struct path *path)
286 if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
291 ret = check_quotactl_permission(sb, type, cmd, id);
297 return quota_quotaon(sb, type, cmd, id, path);
299 if (!sb->s_qcop->quota_off)
301 return sb->s_qcop->quota_off(sb, type);
303 return quota_getfmt(sb, type, addr);
305 return quota_getinfo(sb, type, addr);
307 return quota_setinfo(sb, type, addr);
309 return quota_getquota(sb, type, id, addr);
311 return quota_setquota(sb, type, id, addr);
313 if (!sb->s_qcop->quota_sync)
315 return sb->s_qcop->quota_sync(sb, type);
319 return quota_setxstate(sb, cmd, addr);
321 return quota_getxstate(sb, addr);
323 return quota_getxstatev(sb, addr);
325 return quota_setxquota(sb, type, id, addr);
327 return quota_getxquota(sb, type, id, addr);
329 if (sb->s_flags & MS_RDONLY)
331 /* XFS quotas are fully coherent now, making this call a noop */
340 /* Return 1 if 'cmd' will block on frozen filesystem */
341 static int quotactl_cmd_write(int cmd)
356 #endif /* CONFIG_BLOCK */
359 * look up a superblock on which quota ops will be performed
360 * - use the name of a block device to find the superblock thereon
362 static struct super_block *quotactl_block(const char __user *special, int cmd)
365 struct block_device *bdev;
366 struct super_block *sb;
367 struct filename *tmp = getname(special);
370 return ERR_CAST(tmp);
371 bdev = lookup_bdev(tmp->name);
374 return ERR_CAST(bdev);
375 if (quotactl_cmd_write(cmd))
376 sb = get_super_thawed(bdev);
378 sb = get_super(bdev);
381 return ERR_PTR(-ENODEV);
385 return ERR_PTR(-ENODEV);
390 * This is the system call interface. This communicates with
391 * the user-level programs. Currently this only supports diskquota
392 * calls. Maybe we need to add the process quotas etc. in the future,
393 * but we probably should use rlimits for that.
395 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
396 qid_t, id, void __user *, addr)
399 struct super_block *sb = NULL;
400 struct path path, *pathp = NULL;
403 cmds = cmd >> SUBCMDSHIFT;
404 type = cmd & SUBCMDMASK;
407 * As a special case Q_SYNC can be called without a specific device.
408 * It will iterate all superblocks that have quota enabled and call
409 * the sync action on each of them.
413 return quota_sync_all(type);
418 * Path for quotaon has to be resolved before grabbing superblock
419 * because that gets s_umount sem which is also possibly needed by path
420 * resolution (think about autofs) and thus deadlocks could arise.
422 if (cmds == Q_QUOTAON) {
423 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
425 pathp = ERR_PTR(ret);
430 sb = quotactl_block(special, cmds);
436 ret = do_quotactl(sb, type, cmds, id, addr, pathp);
440 if (pathp && !IS_ERR(pathp))