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 */
32 /* allow to query information for dquots we "own" */
35 if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
36 (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
40 if (!capable(CAP_SYS_ADMIN))
44 return security_quotactl(cmd, type, id, sb);
47 static void quota_sync_one(struct super_block *sb, void *arg)
49 if (sb->s_qcop && sb->s_qcop->quota_sync)
50 sb->s_qcop->quota_sync(sb, *(int *)arg);
53 static int quota_sync_all(int type)
57 if (type >= MAXQUOTAS)
59 ret = security_quotactl(Q_SYNC, type, 0, NULL);
61 iterate_supers(quota_sync_one, &type);
65 static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
68 if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_on_meta)
70 if (sb->s_qcop->quota_on_meta)
71 return sb->s_qcop->quota_on_meta(sb, type, id);
74 return sb->s_qcop->quota_on(sb, type, id, path);
77 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
81 down_read(&sb_dqopt(sb)->dqptr_sem);
82 if (!sb_has_quota_active(sb, type)) {
83 up_read(&sb_dqopt(sb)->dqptr_sem);
86 fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
87 up_read(&sb_dqopt(sb)->dqptr_sem);
88 if (copy_to_user(addr, &fmt, sizeof(fmt)))
93 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
95 struct if_dqinfo info;
98 if (!sb->s_qcop->get_info)
100 ret = sb->s_qcop->get_info(sb, type, &info);
101 if (!ret && copy_to_user(addr, &info, sizeof(info)))
106 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
108 struct if_dqinfo info;
110 if (copy_from_user(&info, addr, sizeof(info)))
112 if (!sb->s_qcop->set_info)
114 return sb->s_qcop->set_info(sb, type, &info);
117 static void copy_to_if_dqblk(struct if_dqblk *dst, struct fs_disk_quota *src)
119 dst->dqb_bhardlimit = src->d_blk_hardlimit;
120 dst->dqb_bsoftlimit = src->d_blk_softlimit;
121 dst->dqb_curspace = src->d_bcount;
122 dst->dqb_ihardlimit = src->d_ino_hardlimit;
123 dst->dqb_isoftlimit = src->d_ino_softlimit;
124 dst->dqb_curinodes = src->d_icount;
125 dst->dqb_btime = src->d_btimer;
126 dst->dqb_itime = src->d_itimer;
127 dst->dqb_valid = QIF_ALL;
130 static int quota_getquota(struct super_block *sb, int type, qid_t id,
134 struct fs_disk_quota fdq;
138 if (!sb->s_qcop->get_dqblk)
140 qid = make_kqid(current_user_ns(), type, id);
143 ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
146 copy_to_if_dqblk(&idq, &fdq);
147 if (copy_to_user(addr, &idq, sizeof(idq)))
152 static void copy_from_if_dqblk(struct fs_disk_quota *dst, struct if_dqblk *src)
154 dst->d_blk_hardlimit = src->dqb_bhardlimit;
155 dst->d_blk_softlimit = src->dqb_bsoftlimit;
156 dst->d_bcount = src->dqb_curspace;
157 dst->d_ino_hardlimit = src->dqb_ihardlimit;
158 dst->d_ino_softlimit = src->dqb_isoftlimit;
159 dst->d_icount = src->dqb_curinodes;
160 dst->d_btimer = src->dqb_btime;
161 dst->d_itimer = src->dqb_itime;
163 dst->d_fieldmask = 0;
164 if (src->dqb_valid & QIF_BLIMITS)
165 dst->d_fieldmask |= FS_DQ_BSOFT | FS_DQ_BHARD;
166 if (src->dqb_valid & QIF_SPACE)
167 dst->d_fieldmask |= FS_DQ_BCOUNT;
168 if (src->dqb_valid & QIF_ILIMITS)
169 dst->d_fieldmask |= FS_DQ_ISOFT | FS_DQ_IHARD;
170 if (src->dqb_valid & QIF_INODES)
171 dst->d_fieldmask |= FS_DQ_ICOUNT;
172 if (src->dqb_valid & QIF_BTIME)
173 dst->d_fieldmask |= FS_DQ_BTIMER;
174 if (src->dqb_valid & QIF_ITIME)
175 dst->d_fieldmask |= FS_DQ_ITIMER;
178 static int quota_setquota(struct super_block *sb, int type, qid_t id,
181 struct fs_disk_quota fdq;
185 if (copy_from_user(&idq, addr, sizeof(idq)))
187 if (!sb->s_qcop->set_dqblk)
189 qid = make_kqid(current_user_ns(), type, id);
192 copy_from_if_dqblk(&fdq, &idq);
193 return sb->s_qcop->set_dqblk(sb, qid, &fdq);
196 static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr)
200 if (copy_from_user(&flags, addr, sizeof(flags)))
202 if (!sb->s_qcop->set_xstate)
204 return sb->s_qcop->set_xstate(sb, flags, cmd);
207 static int quota_getxstate(struct super_block *sb, void __user *addr)
209 struct fs_quota_stat fqs;
212 if (!sb->s_qcop->get_xstate)
214 ret = sb->s_qcop->get_xstate(sb, &fqs);
215 if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
220 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
223 struct fs_disk_quota fdq;
226 if (copy_from_user(&fdq, addr, sizeof(fdq)))
228 if (!sb->s_qcop->set_dqblk)
230 qid = make_kqid(current_user_ns(), type, id);
233 return sb->s_qcop->set_dqblk(sb, qid, &fdq);
236 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
239 struct fs_disk_quota fdq;
243 if (!sb->s_qcop->get_dqblk)
245 qid = make_kqid(current_user_ns(), type, id);
248 ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
249 if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
254 /* Copy parameters and call proper function */
255 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
256 void __user *addr, struct path *path)
260 if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
265 ret = check_quotactl_permission(sb, type, cmd, id);
271 return quota_quotaon(sb, type, cmd, id, path);
273 if (!sb->s_qcop->quota_off)
275 return sb->s_qcop->quota_off(sb, type);
277 return quota_getfmt(sb, type, addr);
279 return quota_getinfo(sb, type, addr);
281 return quota_setinfo(sb, type, addr);
283 return quota_getquota(sb, type, id, addr);
285 return quota_setquota(sb, type, id, addr);
287 if (!sb->s_qcop->quota_sync)
289 return sb->s_qcop->quota_sync(sb, type);
293 return quota_setxstate(sb, cmd, addr);
295 return quota_getxstate(sb, addr);
297 return quota_setxquota(sb, type, id, addr);
299 return quota_getxquota(sb, type, id, addr);
301 if (sb->s_flags & MS_RDONLY)
303 /* XFS quotas are fully coherent now, making this call a noop */
310 /* Return 1 if 'cmd' will block on frozen filesystem */
311 static int quotactl_cmd_write(int cmd)
326 * look up a superblock on which quota ops will be performed
327 * - use the name of a block device to find the superblock thereon
329 static struct super_block *quotactl_block(const char __user *special, int cmd)
332 struct block_device *bdev;
333 struct super_block *sb;
334 struct filename *tmp = getname(special);
337 return ERR_CAST(tmp);
338 bdev = lookup_bdev(tmp->name);
341 return ERR_CAST(bdev);
342 if (quotactl_cmd_write(cmd))
343 sb = get_super_thawed(bdev);
345 sb = get_super(bdev);
348 return ERR_PTR(-ENODEV);
352 return ERR_PTR(-ENODEV);
357 * This is the system call interface. This communicates with
358 * the user-level programs. Currently this only supports diskquota
359 * calls. Maybe we need to add the process quotas etc. in the future,
360 * but we probably should use rlimits for that.
362 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
363 qid_t, id, void __user *, addr)
366 struct super_block *sb = NULL;
367 struct path path, *pathp = NULL;
370 cmds = cmd >> SUBCMDSHIFT;
371 type = cmd & SUBCMDMASK;
374 * As a special case Q_SYNC can be called without a specific device.
375 * It will iterate all superblocks that have quota enabled and call
376 * the sync action on each of them.
380 return quota_sync_all(type);
385 * Path for quotaon has to be resolved before grabbing superblock
386 * because that gets s_umount sem which is also possibly needed by path
387 * resolution (think about autofs) and thus deadlocks could arise.
389 if (cmds == Q_QUOTAON) {
390 ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
392 pathp = ERR_PTR(ret);
397 sb = quotactl_block(special, cmds);
403 ret = do_quotactl(sb, type, cmds, id, addr, pathp);
407 if (pathp && !IS_ERR(pathp))