quotaio.c revision 0ce0172984c807d3366e8db6e2a2b6ecae314832 
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 release_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 EXT2FS_ATTR((unused)))
106{
107	blk64_t	block;
108
109	block = *blocknr;
110	ext2fs_block_alloc_stats2(fs, block, -1);
111	return 0;
112}
113
114static int compute_num_blocks_proc(ext2_filsys fs, blk64_t *blocknr,
115			       e2_blkcnt_t blockcnt EXT2FS_ATTR((unused)),
116			       blk64_t ref_block EXT2FS_ATTR((unused)),
117			       int ref_offset EXT2FS_ATTR((unused)),
118			       void *private)
119{
120	blk64_t *num_blocks = private;
121
122	*num_blocks += 1;
123	return 0;
124}
125
126errcode_t quota_inode_truncate(ext2_filsys fs, ext2_ino_t ino)
127{
128	struct ext2_inode inode;
129	errcode_t err;
130
131	if ((err = ext2fs_read_inode(fs, ino, &inode)))
132		return err;
133
134	if ((ino == EXT4_USR_QUOTA_INO) || (ino == EXT4_GRP_QUOTA_INO)) {
135		inode.i_dtime = fs->now ? fs->now : time(0);
136		if (!ext2fs_inode_has_valid_blocks2(fs, &inode))
137			return 0;
138
139		ext2fs_block_iterate3(fs, ino, BLOCK_FLAG_READ_ONLY, NULL,
140				      release_blocks_proc, NULL);
141		fs->flags &= ~EXT2_FLAG_SUPER_ONLY;
142		memset(&inode, 0, sizeof(struct ext2_inode));
143	} else {
144		inode.i_flags &= ~EXT2_IMMUTABLE_FL;
145	}
146	err = ext2fs_write_inode(fs, ino, &inode);
147	return err;
148}
149
150static ext2_off64_t compute_inode_size(ext2_filsys fs, ext2_ino_t ino)
151{
152	blk64_t num_blocks = 0;
153
154	ext2fs_block_iterate3(fs, ino,
155			      BLOCK_FLAG_READ_ONLY,
156			      NULL,
157			      compute_num_blocks_proc,
158			      &num_blocks);
159	return num_blocks * fs->blocksize;
160}
161
162/* Functions to read/write quota file. */
163static unsigned int quota_write_nomount(struct quota_file *qf,
164					ext2_loff_t offset,
165					void *buf, unsigned int size)
166{
167	ext2_file_t	e2_file = qf->e2_file;
168	unsigned int	bytes_written = 0;
169	errcode_t	err;
170
171	err = ext2fs_file_llseek(e2_file, offset, EXT2_SEEK_SET, NULL);
172	if (err) {
173		log_err("ext2fs_file_llseek failed: %ld", err);
174		return 0;
175	}
176
177	err = ext2fs_file_write(e2_file, buf, size, &bytes_written);
178	if (err) {
179		log_err("ext2fs_file_write failed: %ld", err);
180		return 0;
181	}
182
183	/* Correct inode.i_size is set in end_io. */
184	return bytes_written;
185}
186
187static unsigned int quota_read_nomount(struct quota_file *qf,
188				       ext2_loff_t offset,
189				       void *buf, unsigned int size)
190{
191	ext2_file_t	e2_file = qf->e2_file;
192	unsigned int	bytes_read = 0;
193	errcode_t	err;
194
195	err = ext2fs_file_llseek(e2_file, offset, EXT2_SEEK_SET, NULL);
196	if (err) {
197		log_err("ext2fs_file_llseek failed: %ld", err);
198		return 0;
199	}
200
201	err = ext2fs_file_read(e2_file, buf, size, &bytes_read);
202	if (err) {
203		log_err("ext2fs_file_read failed: %ld", err);
204		return 0;
205	}
206
207	return bytes_read;
208}
209
210/*
211 * Detect quota format and initialize quota IO
212 */
213errcode_t quota_file_open(struct quota_handle *h, ext2_filsys fs,
214			  ext2_ino_t qf_ino, int type, int fmt, int flags)
215{
216	ext2_file_t e2_file;
217	errcode_t err;
218
219	if (fmt == -1)
220		fmt = QFMT_VFS_V1;
221
222	err = ext2fs_read_bitmaps(fs);
223	if (err)
224		return err;
225
226	log_debug("Opening quota ino=%lu, type=%d", qf_ino, type);
227	err = ext2fs_file_open(fs, qf_ino, flags, &e2_file);
228	if (err) {
229		log_err("ext2fs_file_open failed: %s", error_message(err));
230		return err;
231	}
232	h->qh_qf.e2_file = e2_file;
233
234	h->qh_qf.fs = fs;
235	h->qh_qf.ino = qf_ino;
236	h->e2fs_write = quota_write_nomount;
237	h->e2fs_read = quota_read_nomount;
238	h->qh_io_flags = 0;
239	h->qh_type = type;
240	h->qh_fmt = fmt;
241	memset(&h->qh_info, 0, sizeof(h->qh_info));
242	h->qh_ops = &quotafile_ops_2;
243
244	if (h->qh_ops->check_file &&
245	    (h->qh_ops->check_file(h, type, fmt) == 0)) {
246		log_err("qh_ops->check_file failed");
247		ext2fs_file_close(e2_file);
248		return -1;
249	}
250
251	if (h->qh_ops->init_io && (h->qh_ops->init_io(h) < 0)) {
252		log_err("qh_ops->init_io failed");
253		ext2fs_file_close(e2_file);
254		return -1;
255	}
256
257	return 0;
258}
259
260static errcode_t quota_inode_init_new(ext2_filsys fs, ext2_ino_t ino)
261{
262	struct ext2_inode inode;
263	errcode_t err = 0;
264
265	err = ext2fs_read_inode(fs, ino, &inode);
266	if (err) {
267		log_err("ex2fs_read_inode failed");
268		return err;
269	}
270
271	if (EXT2_I_SIZE(&inode))
272		quota_inode_truncate(fs, ino);
273
274	memset(&inode, 0, sizeof(struct ext2_inode));
275	ext2fs_iblk_set(fs, &inode, 0);
276	inode.i_atime = inode.i_mtime =
277		inode.i_ctime = fs->now ? fs->now : time(0);
278	inode.i_links_count = 1;
279	inode.i_mode = LINUX_S_IFREG | 0600;
280	inode.i_flags |= EXT2_IMMUTABLE_FL;
281	if (fs->super->s_feature_incompat &
282			EXT3_FEATURE_INCOMPAT_EXTENTS)
283		inode.i_flags |= EXT4_EXTENTS_FL;
284
285	err = ext2fs_write_new_inode(fs, ino, &inode);
286	if (err) {
287		log_err("ext2fs_write_new_inode failed: %ld", err);
288		return err;
289	}
290	return err;
291}
292
293/*
294 * Create new quotafile of specified format on given filesystem
295 */
296errcode_t quota_file_create(struct quota_handle *h, ext2_filsys fs, int type, int fmt)
297{
298	ext2_file_t e2_file;
299	int err;
300	unsigned long qf_inum;
301
302	if (fmt == -1)
303		fmt = QFMT_VFS_V1;
304
305	h->qh_qf.fs = fs;
306	if (type == USRQUOTA)
307		qf_inum = EXT4_USR_QUOTA_INO;
308	else if (type == GRPQUOTA)
309		qf_inum = EXT4_GRP_QUOTA_INO;
310	else
311		return -1;
312
313	err = ext2fs_read_bitmaps(fs);
314	if (err)
315		goto out_err;
316
317	err = quota_inode_init_new(fs, qf_inum);
318	if (err) {
319		log_err("init_new_quota_inode failed");
320		goto out_err;
321	}
322	h->qh_qf.ino = qf_inum;
323	h->e2fs_write = quota_write_nomount;
324	h->e2fs_read = quota_read_nomount;
325
326	log_debug("Creating quota ino=%lu, type=%d", qf_inum, type);
327	err = ext2fs_file_open(fs, qf_inum,
328			EXT2_FILE_WRITE | EXT2_FILE_CREATE, &e2_file);
329	if (err) {
330		log_err("ext2fs_file_open failed: %d", err);
331		goto out_err;
332	}
333	h->qh_qf.e2_file = e2_file;
334
335	h->qh_io_flags = 0;
336	h->qh_type = type;
337	h->qh_fmt = fmt;
338	memset(&h->qh_info, 0, sizeof(h->qh_info));
339	h->qh_ops = &quotafile_ops_2;
340
341	if (h->qh_ops->new_io && (h->qh_ops->new_io(h) < 0)) {
342		log_err("qh_ops->new_io failed");
343		goto out_err1;
344	}
345
346	return 0;
347
348out_err1:
349	ext2fs_file_close(e2_file);
350out_err:
351
352	if (qf_inum)
353		quota_inode_truncate(fs, qf_inum);
354
355	return -1;
356}
357
358/*
359 * Close quotafile and release handle
360 */
361errcode_t quota_file_close(struct quota_handle *h)
362{
363	if (h->qh_io_flags & IOFL_INFODIRTY) {
364		if (h->qh_ops->write_info && h->qh_ops->write_info(h) < 0)
365			return -1;
366		h->qh_io_flags &= ~IOFL_INFODIRTY;
367	}
368
369	if (h->qh_ops->end_io && h->qh_ops->end_io(h) < 0)
370		return -1;
371	if (h->qh_qf.e2_file) {
372		ext2fs_file_flush(h->qh_qf.e2_file);
373		ext2fs_file_set_size2(h->qh_qf.e2_file,
374			compute_inode_size(h->qh_qf.fs, h->qh_qf.ino));
375		ext2fs_file_close(h->qh_qf.e2_file);
376	}
377
378	return 0;
379}
380
381/*
382 * Create empty quota structure
383 */
384struct dquot *get_empty_dquot(void)
385{
386	struct dquot *dquot;
387
388	if (ext2fs_get_memzero(sizeof(struct dquot), &dquot)) {
389		log_err("Failed to allocate dquot");
390		return NULL;
391	}
392
393	dquot->dq_id = -1;
394	return dquot;
395}
396