quotaio.c revision a9825cfe945e6dc6e300f89e7e613b80afde0189 
1/** quotaio.c
2 *
3 * Generic IO operations on quotafiles
4 * Jan Kara <jack@suse.cz> - sponsored by SuSE CR
5 * Aditya Kali <adityakali@google.com> - Ported to e2fsprogs
6 */
7
8#include "config.h"
9#include <stdio.h>
10#include <errno.h>
11#include <string.h>
12#include <unistd.h>
13#include <stdlib.h>
14#include <time.h>
15#include <sys/types.h>
16#include <sys/stat.h>
17#include <sys/file.h>
18
19#include "common.h"
20#include "quotaio.h"
21
22static const char * const extensions[MAXQUOTAS] = {"user", "group"};
23static const char * const basenames[] = {
24	"",		/* undefined */
25	"quota",	/* QFMT_VFS_OLD */
26	"aquota",	/* QFMT_VFS_V0 */
27	"",		/* QFMT_OCFS2 */
28	"aquota"	/* QFMT_VFS_V1 */
29};
30
31/* Header in all newer quotafiles */
32struct disk_dqheader {
33	u_int32_t dqh_magic;
34	u_int32_t dqh_version;
35} __attribute__ ((packed));
36
37/**
38 * Convert type of quota to written representation
39 */
40const char *type2name(int type)
41{
42	return extensions[type];
43}
44
45/**
46 * Creates a quota file name for given type and format.
47 */
48const char *quota_get_qf_name(int type, int fmt, char *buf)
49{
50	if (!buf)
51		return NULL;
52	snprintf(buf, QUOTA_NAME_LEN, "%s.%s",
53		 basenames[fmt], extensions[type]);
54
55	return buf;
56}
57
58const char *quota_get_qf_path(const char *mntpt, int qtype, int fmt,
59			      char *path_buf, size_t path_buf_size)
60{
61	char qf_name[QUOTA_NAME_LEN];
62
63	if (!mntpt || !path_buf || !path_buf_size)
64		return NULL;
65
66	strncpy(path_buf, mntpt, path_buf_size);
67	strncat(path_buf, "/", 1);
68	strncat(path_buf, quota_get_qf_name(qtype, fmt, qf_name),
69		path_buf_size - strlen(path_buf));
70
71	return path_buf;
72}
73
74/*
75 * Set grace time if needed
76 */
77void update_grace_times(struct dquot *q)
78{
79	time_t now;
80
81	time(&now);
82	if (q->dq_dqb.dqb_bsoftlimit && toqb(q->dq_dqb.dqb_curspace) >
83			q->dq_dqb.dqb_bsoftlimit) {
84		if (!q->dq_dqb.dqb_btime)
85			q->dq_dqb.dqb_btime =
86				now + q->dq_h->qh_info.dqi_bgrace;
87	} else {
88		q->dq_dqb.dqb_btime = 0;
89	}
90
91	if (q->dq_dqb.dqb_isoftlimit && q->dq_dqb.dqb_curinodes >
92			q->dq_dqb.dqb_isoftlimit) {
93		if (!q->dq_dqb.dqb_itime)
94				q->dq_dqb.dqb_itime =
95					now + q->dq_h->qh_info.dqi_igrace;
96	} else {
97		q->dq_dqb.dqb_itime = 0;
98	}
99}
100
101static int compute_num_blocks_proc(ext2_filsys fs, blk64_t *blocknr,
102			       e2_blkcnt_t blockcnt EXT2FS_ATTR((unused)),
103			       blk64_t ref_block EXT2FS_ATTR((unused)),
104			       int ref_offset EXT2FS_ATTR((unused)),
105			       void *private)
106{
107	blk64_t *num_blocks = private;
108
109	*num_blocks += 1;
110	return 0;
111}
112
113errcode_t quota_inode_truncate(ext2_filsys fs, ext2_ino_t ino)
114{
115	struct ext2_inode inode;
116	errcode_t err;
117
118	if ((err = ext2fs_read_inode(fs, ino, &inode)))
119		return err;
120
121	if ((ino == EXT4_USR_QUOTA_INO) || (ino == EXT4_GRP_QUOTA_INO)) {
122		inode.i_dtime = fs->now ? fs->now : time(0);
123		if (!ext2fs_inode_has_valid_blocks2(fs, &inode))
124			return 0;
125		err = ext2fs_punch(fs, ino, &inode, NULL, 0, ~0ULL);
126		if (err)
127			return err;
128		fs->flags &= ~EXT2_FLAG_SUPER_ONLY;
129		memset(&inode, 0, sizeof(struct ext2_inode));
130	} else {
131		inode.i_flags &= ~EXT2_IMMUTABLE_FL;
132	}
133	err = ext2fs_write_inode(fs, ino, &inode);
134	return err;
135}
136
137static ext2_off64_t compute_inode_size(ext2_filsys fs, ext2_ino_t ino)
138{
139	blk64_t num_blocks = 0;
140
141	ext2fs_block_iterate3(fs, ino,
142			      BLOCK_FLAG_READ_ONLY,
143			      NULL,
144			      compute_num_blocks_proc,
145			      &num_blocks);
146	return num_blocks * fs->blocksize;
147}
148
149/* Functions to read/write quota file. */
150static unsigned int quota_write_nomount(struct quota_file *qf,
151					ext2_loff_t offset,
152					void *buf, unsigned int size)
153{
154	ext2_file_t	e2_file = qf->e2_file;
155	unsigned int	bytes_written = 0;
156	errcode_t	err;
157
158	err = ext2fs_file_llseek(e2_file, offset, EXT2_SEEK_SET, NULL);
159	if (err) {
160		log_err("ext2fs_file_llseek failed: %ld", err);
161		return 0;
162	}
163
164	err = ext2fs_file_write(e2_file, buf, size, &bytes_written);
165	if (err) {
166		log_err("ext2fs_file_write failed: %ld", err);
167		return 0;
168	}
169
170	/* Correct inode.i_size is set in end_io. */
171	return bytes_written;
172}
173
174static unsigned int quota_read_nomount(struct quota_file *qf,
175				       ext2_loff_t offset,
176				       void *buf, unsigned int size)
177{
178	ext2_file_t	e2_file = qf->e2_file;
179	unsigned int	bytes_read = 0;
180	errcode_t	err;
181
182	err = ext2fs_file_llseek(e2_file, offset, EXT2_SEEK_SET, NULL);
183	if (err) {
184		log_err("ext2fs_file_llseek failed: %ld", err);
185		return 0;
186	}
187
188	err = ext2fs_file_read(e2_file, buf, size, &bytes_read);
189	if (err) {
190		log_err("ext2fs_file_read failed: %ld", err);
191		return 0;
192	}
193
194	return bytes_read;
195}
196
197/*
198 * Detect quota format and initialize quota IO
199 */
200errcode_t quota_file_open(struct quota_handle *h, ext2_filsys fs,
201			  ext2_ino_t qf_ino, int type, int fmt, int flags)
202{
203	ext2_file_t e2_file;
204	errcode_t err;
205
206	if (fmt == -1)
207		fmt = QFMT_VFS_V1;
208
209	err = ext2fs_read_bitmaps(fs);
210	if (err)
211		return err;
212
213	log_debug("Opening quota ino=%lu, type=%d", qf_ino, type);
214	err = ext2fs_file_open(fs, qf_ino, flags, &e2_file);
215	if (err) {
216		log_err("ext2fs_file_open failed: %s", error_message(err));
217		return err;
218	}
219	h->qh_qf.e2_file = e2_file;
220
221	h->qh_qf.fs = fs;
222	h->qh_qf.ino = qf_ino;
223	h->e2fs_write = quota_write_nomount;
224	h->e2fs_read = quota_read_nomount;
225	h->qh_io_flags = 0;
226	h->qh_type = type;
227	h->qh_fmt = fmt;
228	memset(&h->qh_info, 0, sizeof(h->qh_info));
229	h->qh_ops = &quotafile_ops_2;
230
231	if (h->qh_ops->check_file &&
232	    (h->qh_ops->check_file(h, type, fmt) == 0)) {
233		log_err("qh_ops->check_file failed");
234		ext2fs_file_close(e2_file);
235		return -1;
236	}
237
238	if (h->qh_ops->init_io && (h->qh_ops->init_io(h) < 0)) {
239		log_err("qh_ops->init_io failed");
240		ext2fs_file_close(e2_file);
241		return -1;
242	}
243
244	return 0;
245}
246
247static errcode_t quota_inode_init_new(ext2_filsys fs, ext2_ino_t ino)
248{
249	struct ext2_inode inode;
250	errcode_t err = 0;
251
252	err = ext2fs_read_inode(fs, ino, &inode);
253	if (err) {
254		log_err("ex2fs_read_inode failed");
255		return err;
256	}
257
258	if (EXT2_I_SIZE(&inode))
259		quota_inode_truncate(fs, ino);
260
261	memset(&inode, 0, sizeof(struct ext2_inode));
262	ext2fs_iblk_set(fs, &inode, 0);
263	inode.i_atime = inode.i_mtime =
264		inode.i_ctime = fs->now ? fs->now : time(0);
265	inode.i_links_count = 1;
266	inode.i_mode = LINUX_S_IFREG | 0600;
267	inode.i_flags |= EXT2_IMMUTABLE_FL;
268	if (fs->super->s_feature_incompat &
269			EXT3_FEATURE_INCOMPAT_EXTENTS)
270		inode.i_flags |= EXT4_EXTENTS_FL;
271
272	err = ext2fs_write_new_inode(fs, ino, &inode);
273	if (err) {
274		log_err("ext2fs_write_new_inode failed: %ld", err);
275		return err;
276	}
277	return err;
278}
279
280/*
281 * Create new quotafile of specified format on given filesystem
282 */
283errcode_t quota_file_create(struct quota_handle *h, ext2_filsys fs, int type, int fmt)
284{
285	ext2_file_t e2_file;
286	int err;
287	unsigned long qf_inum;
288
289	if (fmt == -1)
290		fmt = QFMT_VFS_V1;
291
292	h->qh_qf.fs = fs;
293	if (type == USRQUOTA)
294		qf_inum = EXT4_USR_QUOTA_INO;
295	else if (type == GRPQUOTA)
296		qf_inum = EXT4_GRP_QUOTA_INO;
297	else
298		return -1;
299
300	err = ext2fs_read_bitmaps(fs);
301	if (err)
302		goto out_err;
303
304	err = quota_inode_init_new(fs, qf_inum);
305	if (err) {
306		log_err("init_new_quota_inode failed");
307		goto out_err;
308	}
309	h->qh_qf.ino = qf_inum;
310	h->e2fs_write = quota_write_nomount;
311	h->e2fs_read = quota_read_nomount;
312
313	log_debug("Creating quota ino=%lu, type=%d", qf_inum, type);
314	err = ext2fs_file_open(fs, qf_inum,
315			EXT2_FILE_WRITE | EXT2_FILE_CREATE, &e2_file);
316	if (err) {
317		log_err("ext2fs_file_open failed: %d", err);
318		goto out_err;
319	}
320	h->qh_qf.e2_file = e2_file;
321
322	h->qh_io_flags = 0;
323	h->qh_type = type;
324	h->qh_fmt = fmt;
325	memset(&h->qh_info, 0, sizeof(h->qh_info));
326	h->qh_ops = &quotafile_ops_2;
327
328	if (h->qh_ops->new_io && (h->qh_ops->new_io(h) < 0)) {
329		log_err("qh_ops->new_io failed");
330		goto out_err1;
331	}
332
333	return 0;
334
335out_err1:
336	ext2fs_file_close(e2_file);
337out_err:
338
339	if (qf_inum)
340		quota_inode_truncate(fs, qf_inum);
341
342	return -1;
343}
344
345/*
346 * Close quotafile and release handle
347 */
348errcode_t quota_file_close(struct quota_handle *h)
349{
350	if (h->qh_io_flags & IOFL_INFODIRTY) {
351		if (h->qh_ops->write_info && h->qh_ops->write_info(h) < 0)
352			return -1;
353		h->qh_io_flags &= ~IOFL_INFODIRTY;
354	}
355
356	if (h->qh_ops->end_io && h->qh_ops->end_io(h) < 0)
357		return -1;
358	if (h->qh_qf.e2_file) {
359		ext2fs_file_flush(h->qh_qf.e2_file);
360		ext2fs_file_set_size2(h->qh_qf.e2_file,
361			compute_inode_size(h->qh_qf.fs, h->qh_qf.ino));
362		ext2fs_file_close(h->qh_qf.e2_file);
363	}
364
365	return 0;
366}
367
368/*
369 * Create empty quota structure
370 */
371struct dquot *get_empty_dquot(void)
372{
373	struct dquot *dquot;
374
375	if (ext2fs_get_memzero(sizeof(struct dquot), &dquot)) {
376		log_err("Failed to allocate dquot");
377		return NULL;
378	}
379
380	dquot->dq_id = -1;
381	return dquot;
382}
383