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 <asm/uaccess.h>
13 #include <linux/kernel.h>
14 #include <linux/security.h>
15 #include <linux/syscalls.h>
16 #include <linux/buffer_head.h>
17 #include <linux/capability.h>
18 #include <linux/quotaops.h>
19 #include <linux/types.h>
20 #include <linux/writeback.h>
22 static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
26 /* these commands do not require any special privilegues */
33 /* allow to query information for dquots we "own" */
36 if ((type == USRQUOTA && current_euid() == id) ||
37 (type == GRPQUOTA && in_egroup_p(id)))
41 if (!capable(CAP_SYS_ADMIN))
45 return security_quotactl(cmd, type, id, sb);
48 static int quota_sync_all(int type)
50 struct super_block *sb;
53 if (type >= MAXQUOTAS)
55 ret = security_quotactl(Q_SYNC, type, 0, NULL);
61 list_for_each_entry(sb, &super_blocks, s_list) {
62 if (!sb->s_qcop || !sb->s_qcop->quota_sync)
66 spin_unlock(&sb_lock);
67 down_read(&sb->s_umount);
69 sb->s_qcop->quota_sync(sb, type, 1);
70 up_read(&sb->s_umount);
72 if (__put_super_and_need_restart(sb))
75 spin_unlock(&sb_lock);
80 static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
86 pathname = getname(addr);
88 return PTR_ERR(pathname);
89 if (sb->s_qcop->quota_on)
90 ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0);
95 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
99 down_read(&sb_dqopt(sb)->dqptr_sem);
100 if (!sb_has_quota_active(sb, type)) {
101 up_read(&sb_dqopt(sb)->dqptr_sem);
104 fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
105 up_read(&sb_dqopt(sb)->dqptr_sem);
106 if (copy_to_user(addr, &fmt, sizeof(fmt)))
111 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
113 struct if_dqinfo info;
116 if (!sb_has_quota_active(sb, type))
118 if (!sb->s_qcop->get_info)
120 ret = sb->s_qcop->get_info(sb, type, &info);
121 if (!ret && copy_to_user(addr, &info, sizeof(info)))
126 static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
128 struct if_dqinfo info;
130 if (copy_from_user(&info, addr, sizeof(info)))
132 if (!sb_has_quota_active(sb, type))
134 if (!sb->s_qcop->set_info)
136 return sb->s_qcop->set_info(sb, type, &info);
139 static void copy_to_if_dqblk(struct if_dqblk *dst, struct fs_disk_quota *src)
141 dst->dqb_bhardlimit = src->d_blk_hardlimit;
142 dst->dqb_bsoftlimit = src->d_blk_softlimit;
143 dst->dqb_curspace = src->d_bcount;
144 dst->dqb_ihardlimit = src->d_ino_hardlimit;
145 dst->dqb_isoftlimit = src->d_ino_softlimit;
146 dst->dqb_curinodes = src->d_icount;
147 dst->dqb_btime = src->d_btimer;
148 dst->dqb_itime = src->d_itimer;
149 dst->dqb_valid = QIF_ALL;
152 static int quota_getquota(struct super_block *sb, int type, qid_t id,
155 struct fs_disk_quota fdq;
159 if (!sb->s_qcop->get_dqblk)
161 ret = sb->s_qcop->get_dqblk(sb, type, id, &fdq);
164 copy_to_if_dqblk(&idq, &fdq);
165 if (copy_to_user(addr, &idq, sizeof(idq)))
170 static void copy_from_if_dqblk(struct fs_disk_quota *dst, struct if_dqblk *src)
172 dst->d_blk_hardlimit = src->dqb_bhardlimit;
173 dst->d_blk_softlimit = src->dqb_bsoftlimit;
174 dst->d_bcount = src->dqb_curspace;
175 dst->d_ino_hardlimit = src->dqb_ihardlimit;
176 dst->d_ino_softlimit = src->dqb_isoftlimit;
177 dst->d_icount = src->dqb_curinodes;
178 dst->d_btimer = src->dqb_btime;
179 dst->d_itimer = src->dqb_itime;
181 dst->d_fieldmask = 0;
182 if (src->dqb_valid & QIF_BLIMITS)
183 dst->d_fieldmask |= FS_DQ_BSOFT | FS_DQ_BHARD;
184 if (src->dqb_valid & QIF_SPACE)
185 dst->d_fieldmask |= FS_DQ_BCOUNT;
186 if (src->dqb_valid & QIF_ILIMITS)
187 dst->d_fieldmask |= FS_DQ_ISOFT | FS_DQ_IHARD;
188 if (src->dqb_valid & QIF_INODES)
189 dst->d_fieldmask |= FS_DQ_ICOUNT;
190 if (src->dqb_valid & QIF_BTIME)
191 dst->d_fieldmask |= FS_DQ_BTIMER;
192 if (src->dqb_valid & QIF_ITIME)
193 dst->d_fieldmask |= FS_DQ_ITIMER;
196 static int quota_setquota(struct super_block *sb, int type, qid_t id,
199 struct fs_disk_quota fdq;
202 if (copy_from_user(&idq, addr, sizeof(idq)))
204 if (!sb->s_qcop->set_dqblk)
206 copy_from_if_dqblk(&fdq, &idq);
207 return sb->s_qcop->set_dqblk(sb, type, id, &fdq);
210 static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr)
214 if (copy_from_user(&flags, addr, sizeof(flags)))
216 if (!sb->s_qcop->set_xstate)
218 return sb->s_qcop->set_xstate(sb, flags, cmd);
221 static int quota_getxstate(struct super_block *sb, void __user *addr)
223 struct fs_quota_stat fqs;
226 if (!sb->s_qcop->get_xstate)
228 ret = sb->s_qcop->get_xstate(sb, &fqs);
229 if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
234 static int quota_setxquota(struct super_block *sb, int type, qid_t id,
237 struct fs_disk_quota fdq;
239 if (copy_from_user(&fdq, addr, sizeof(fdq)))
241 if (!sb->s_qcop->set_dqblk)
243 return sb->s_qcop->set_dqblk(sb, type, id, &fdq);
246 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
249 struct fs_disk_quota fdq;
252 if (!sb->s_qcop->get_dqblk)
254 ret = sb->s_qcop->get_dqblk(sb, type, id, &fdq);
255 if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
260 /* Copy parameters and call proper function */
261 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
266 if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
271 ret = check_quotactl_permission(sb, type, cmd, id);
277 return quota_quotaon(sb, type, cmd, id, addr);
279 if (!sb->s_qcop->quota_off)
281 return sb->s_qcop->quota_off(sb, type, 0);
283 return quota_getfmt(sb, type, addr);
285 return quota_getinfo(sb, type, addr);
287 return quota_setinfo(sb, type, addr);
289 return quota_getquota(sb, type, id, addr);
291 return quota_setquota(sb, type, id, addr);
293 if (!sb->s_qcop->quota_sync)
295 return sb->s_qcop->quota_sync(sb, type, 1);
299 return quota_setxstate(sb, cmd, addr);
301 return quota_getxstate(sb, addr);
303 return quota_setxquota(sb, type, id, addr);
305 return quota_getxquota(sb, type, id, addr);
307 /* caller already holds s_umount */
308 if (sb->s_flags & MS_RDONLY)
310 writeback_inodes_sb(sb);
318 * look up a superblock on which quota ops will be performed
319 * - use the name of a block device to find the superblock thereon
321 static struct super_block *quotactl_block(const char __user *special)
324 struct block_device *bdev;
325 struct super_block *sb;
326 char *tmp = getname(special);
329 return ERR_CAST(tmp);
330 bdev = lookup_bdev(tmp);
333 return ERR_CAST(bdev);
334 sb = get_super(bdev);
337 return ERR_PTR(-ENODEV);
341 return ERR_PTR(-ENODEV);
346 * This is the system call interface. This communicates with
347 * the user-level programs. Currently this only supports diskquota
348 * calls. Maybe we need to add the process quotas etc. in the future,
349 * but we probably should use rlimits for that.
351 SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
352 qid_t, id, void __user *, addr)
355 struct super_block *sb = NULL;
358 cmds = cmd >> SUBCMDSHIFT;
359 type = cmd & SUBCMDMASK;
362 * As a special case Q_SYNC can be called without a specific device.
363 * It will iterate all superblocks that have quota enabled and call
364 * the sync action on each of them.
368 return quota_sync_all(type);
372 sb = quotactl_block(special);
376 ret = do_quotactl(sb, type, cmds, id, addr);