46 */
47
48#include <sys/param.h>
49#include <sys/systm.h>
50#include <sys/namei.h>
51#include <sys/bio.h>
52#include <sys/buf.h>
53#include <sys/mount.h>
54#include <sys/vnode.h>
55#include <sys/malloc.h>
56#include <sys/dirent.h>
57#include <sys/sysctl.h>
58
59#include <ufs/ufs/dir.h>
60
61#include <gnu/ext2fs/inode.h>
62#include <gnu/ext2fs/ext2_mount.h>
63#include <gnu/ext2fs/ext2_extern.h>
64#include <gnu/ext2fs/ext2_fs.h>
65#include <gnu/ext2fs/ext2_fs_sb.h>
66
67#ifdef DIAGNOSTIC
68static int dirchk = 1;
69#else
70static int dirchk = 0;
71#endif
72
73SYSCTL_NODE(_vfs, OID_AUTO, e2fs, CTLFLAG_RD, 0, "EXT2FS filesystem");
74SYSCTL_INT(_vfs_e2fs, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0, "");
75
76/*
77 DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512)
78 while it is the native blocksize in ext2fs - thus, a #define
79 is no longer appropriate
80*/
81#undef DIRBLKSIZ
82
83static u_char ext2_ft_to_dt[] = {
84 DT_UNKNOWN, /* EXT2_FT_UNKNOWN */
85 DT_REG, /* EXT2_FT_REG_FILE */
86 DT_DIR, /* EXT2_FT_DIR */
87 DT_CHR, /* EXT2_FT_CHRDEV */
88 DT_BLK, /* EXT2_FT_BLKDEV */
89 DT_FIFO, /* EXT2_FT_FIFO */
90 DT_SOCK, /* EXT2_FT_SOCK */
91 DT_LNK, /* EXT2_FT_SYMLINK */
92};
93#define FTTODT(ft) \
94 ((ft) > sizeof(ext2_ft_to_dt) / sizeof(ext2_ft_to_dt[0]) ? \
95 DT_UNKNOWN : ext2_ft_to_dt[(ft)])
96
97static u_char dt_to_ext2_ft[] = {
98 EXT2_FT_UNKNOWN, /* DT_UNKNOWN */
99 EXT2_FT_FIFO, /* DT_FIFO */
100 EXT2_FT_CHRDEV, /* DT_CHR */
101 EXT2_FT_UNKNOWN, /* unused */
102 EXT2_FT_DIR, /* DT_DIR */
103 EXT2_FT_UNKNOWN, /* unused */
104 EXT2_FT_BLKDEV, /* DT_BLK */
105 EXT2_FT_UNKNOWN, /* unused */
106 EXT2_FT_REG_FILE, /* DT_REG */
107 EXT2_FT_UNKNOWN, /* unused */
108 EXT2_FT_SYMLINK, /* DT_LNK */
109 EXT2_FT_UNKNOWN, /* unused */
110 EXT2_FT_SOCK, /* DT_SOCK */
111 EXT2_FT_UNKNOWN, /* unused */
112 EXT2_FT_UNKNOWN, /* DT_WHT */
113};
114#define DTTOFT(dt) \
115 ((dt) > sizeof(dt_to_ext2_ft) / sizeof(dt_to_ext2_ft[0]) ? \
116 EXT2_FT_UNKNOWN : dt_to_ext2_ft[(dt)])
117
118static int ext2_dirbadentry(struct vnode *dp, struct ext2_dir_entry_2 *de,
119 int entryoffsetinblock);
120
121/*
122 * Vnode op for reading directories.
123 *
124 * The routine below assumes that the on-disk format of a directory
125 * is the same as that defined by <sys/dirent.h>. If the on-disk
126 * format changes, then it will be necessary to do a conversion
127 * from the on-disk format that read returns to the format defined
128 * by <sys/dirent.h>.
129 */
130/*
131 * this is exactly what we do here - the problem is that the conversion
132 * will blow up some entries by four bytes, so it can't be done in place.
133 * This is too bad. Right now the conversion is done entry by entry, the
134 * converted entry is sent via uiomove.
135 *
136 * XXX allocate a buffer, convert as many entries as possible, then send
137 * the whole buffer to uiomove
138 */
139int
140ext2_readdir(ap)
141 struct vop_readdir_args /* {
142 struct vnode *a_vp;
143 struct uio *a_uio;
144 struct ucred *a_cred;
145 } */ *ap;
146{
147 struct uio *uio = ap->a_uio;
148 int count, error;
149
150 struct ext2_dir_entry_2 *edp, *dp;
151 int ncookies;
152 struct dirent dstdp;
153 struct uio auio;
154 struct iovec aiov;
155 caddr_t dirbuf;
156 int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->s_blocksize;
157 int readcnt;
158 off_t startoffset = uio->uio_offset;
159
160 count = uio->uio_resid;
161 /*
162 * Avoid complications for partial directory entries by adjusting
163 * the i/o to end at a block boundary. Don't give up (like ufs
164 * does) if the initial adjustment gives a negative count, since
165 * many callers don't supply a large enough buffer. The correct
166 * size is a little larger than DIRBLKSIZ to allow for expansion
167 * of directory entries, but some callers just use 512.
168 */
169 count -= (uio->uio_offset + count) & (DIRBLKSIZ -1);
170 if (count <= 0)
171 count += DIRBLKSIZ;
172
173#ifdef EXT2FS_DEBUG
174 printf("ext2_readdir: uio_offset = %lld, uio_resid = %d, count = %d\n",
175 uio->uio_offset, uio->uio_resid, count);
176#endif
177
178 auio = *uio;
179 auio.uio_iov = &aiov;
180 auio.uio_iovcnt = 1;
181 auio.uio_resid = count;
182 auio.uio_segflg = UIO_SYSSPACE;
183 aiov.iov_len = count;
184 MALLOC(dirbuf, caddr_t, count, M_TEMP, M_WAITOK);
185 aiov.iov_base = dirbuf;
186 error = VOP_READ(ap->a_vp, &auio, 0, ap->a_cred);
187 if (error == 0) {
188 readcnt = count - auio.uio_resid;
189 edp = (struct ext2_dir_entry_2 *)&dirbuf[readcnt];
190 ncookies = 0;
191 bzero(&dstdp, offsetof(struct dirent, d_name));
192 for (dp = (struct ext2_dir_entry_2 *)dirbuf;
193 !error && uio->uio_resid > 0 && dp < edp; ) {
194 /*-
195 * "New" ext2fs directory entries differ in 3 ways
196 * from ufs on-disk ones:
197 * - the name is not necessarily NUL-terminated.
198 * - the file type field always exists and always
199 * follows the name length field.
200 * - the file type is encoded in a different way.
201 *
202 * "Old" ext2fs directory entries need no special
203 * conversions, since they binary compatible with
204 * "new" entries having a file type of 0 (i.e.,
205 * EXT2_FT_UNKNOWN). Splitting the old name length
206 * field didn't make a mess like it did in ufs,
207 * because ext2fs uses a machine-dependent disk
208 * layout.
209 */
210 dstdp.d_fileno = dp->inode;
211 dstdp.d_type = FTTODT(dp->file_type);
212 dstdp.d_namlen = dp->name_len;
213 dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp);
214 bcopy(dp->name, dstdp.d_name, dstdp.d_namlen);
215 bzero(dstdp.d_name + dstdp.d_namlen,
216 dstdp.d_reclen - offsetof(struct dirent, d_name) -
217 dstdp.d_namlen);
218
219 if (dp->rec_len > 0) {
220 if(dstdp.d_reclen <= uio->uio_resid) {
221 /* advance dp */
222 dp = (struct ext2_dir_entry_2 *)
223 ((char *)dp + dp->rec_len);
224 error =
| 46 */
47
48#include <sys/param.h>
49#include <sys/systm.h>
50#include <sys/namei.h>
51#include <sys/bio.h>
52#include <sys/buf.h>
53#include <sys/mount.h>
54#include <sys/vnode.h>
55#include <sys/malloc.h>
56#include <sys/dirent.h>
57#include <sys/sysctl.h>
58
59#include <ufs/ufs/dir.h>
60
61#include <gnu/ext2fs/inode.h>
62#include <gnu/ext2fs/ext2_mount.h>
63#include <gnu/ext2fs/ext2_extern.h>
64#include <gnu/ext2fs/ext2_fs.h>
65#include <gnu/ext2fs/ext2_fs_sb.h>
66
67#ifdef DIAGNOSTIC
68static int dirchk = 1;
69#else
70static int dirchk = 0;
71#endif
72
73SYSCTL_NODE(_vfs, OID_AUTO, e2fs, CTLFLAG_RD, 0, "EXT2FS filesystem");
74SYSCTL_INT(_vfs_e2fs, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0, "");
75
76/*
77 DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512)
78 while it is the native blocksize in ext2fs - thus, a #define
79 is no longer appropriate
80*/
81#undef DIRBLKSIZ
82
83static u_char ext2_ft_to_dt[] = {
84 DT_UNKNOWN, /* EXT2_FT_UNKNOWN */
85 DT_REG, /* EXT2_FT_REG_FILE */
86 DT_DIR, /* EXT2_FT_DIR */
87 DT_CHR, /* EXT2_FT_CHRDEV */
88 DT_BLK, /* EXT2_FT_BLKDEV */
89 DT_FIFO, /* EXT2_FT_FIFO */
90 DT_SOCK, /* EXT2_FT_SOCK */
91 DT_LNK, /* EXT2_FT_SYMLINK */
92};
93#define FTTODT(ft) \
94 ((ft) > sizeof(ext2_ft_to_dt) / sizeof(ext2_ft_to_dt[0]) ? \
95 DT_UNKNOWN : ext2_ft_to_dt[(ft)])
96
97static u_char dt_to_ext2_ft[] = {
98 EXT2_FT_UNKNOWN, /* DT_UNKNOWN */
99 EXT2_FT_FIFO, /* DT_FIFO */
100 EXT2_FT_CHRDEV, /* DT_CHR */
101 EXT2_FT_UNKNOWN, /* unused */
102 EXT2_FT_DIR, /* DT_DIR */
103 EXT2_FT_UNKNOWN, /* unused */
104 EXT2_FT_BLKDEV, /* DT_BLK */
105 EXT2_FT_UNKNOWN, /* unused */
106 EXT2_FT_REG_FILE, /* DT_REG */
107 EXT2_FT_UNKNOWN, /* unused */
108 EXT2_FT_SYMLINK, /* DT_LNK */
109 EXT2_FT_UNKNOWN, /* unused */
110 EXT2_FT_SOCK, /* DT_SOCK */
111 EXT2_FT_UNKNOWN, /* unused */
112 EXT2_FT_UNKNOWN, /* DT_WHT */
113};
114#define DTTOFT(dt) \
115 ((dt) > sizeof(dt_to_ext2_ft) / sizeof(dt_to_ext2_ft[0]) ? \
116 EXT2_FT_UNKNOWN : dt_to_ext2_ft[(dt)])
117
118static int ext2_dirbadentry(struct vnode *dp, struct ext2_dir_entry_2 *de,
119 int entryoffsetinblock);
120
121/*
122 * Vnode op for reading directories.
123 *
124 * The routine below assumes that the on-disk format of a directory
125 * is the same as that defined by <sys/dirent.h>. If the on-disk
126 * format changes, then it will be necessary to do a conversion
127 * from the on-disk format that read returns to the format defined
128 * by <sys/dirent.h>.
129 */
130/*
131 * this is exactly what we do here - the problem is that the conversion
132 * will blow up some entries by four bytes, so it can't be done in place.
133 * This is too bad. Right now the conversion is done entry by entry, the
134 * converted entry is sent via uiomove.
135 *
136 * XXX allocate a buffer, convert as many entries as possible, then send
137 * the whole buffer to uiomove
138 */
139int
140ext2_readdir(ap)
141 struct vop_readdir_args /* {
142 struct vnode *a_vp;
143 struct uio *a_uio;
144 struct ucred *a_cred;
145 } */ *ap;
146{
147 struct uio *uio = ap->a_uio;
148 int count, error;
149
150 struct ext2_dir_entry_2 *edp, *dp;
151 int ncookies;
152 struct dirent dstdp;
153 struct uio auio;
154 struct iovec aiov;
155 caddr_t dirbuf;
156 int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->s_blocksize;
157 int readcnt;
158 off_t startoffset = uio->uio_offset;
159
160 count = uio->uio_resid;
161 /*
162 * Avoid complications for partial directory entries by adjusting
163 * the i/o to end at a block boundary. Don't give up (like ufs
164 * does) if the initial adjustment gives a negative count, since
165 * many callers don't supply a large enough buffer. The correct
166 * size is a little larger than DIRBLKSIZ to allow for expansion
167 * of directory entries, but some callers just use 512.
168 */
169 count -= (uio->uio_offset + count) & (DIRBLKSIZ -1);
170 if (count <= 0)
171 count += DIRBLKSIZ;
172
173#ifdef EXT2FS_DEBUG
174 printf("ext2_readdir: uio_offset = %lld, uio_resid = %d, count = %d\n",
175 uio->uio_offset, uio->uio_resid, count);
176#endif
177
178 auio = *uio;
179 auio.uio_iov = &aiov;
180 auio.uio_iovcnt = 1;
181 auio.uio_resid = count;
182 auio.uio_segflg = UIO_SYSSPACE;
183 aiov.iov_len = count;
184 MALLOC(dirbuf, caddr_t, count, M_TEMP, M_WAITOK);
185 aiov.iov_base = dirbuf;
186 error = VOP_READ(ap->a_vp, &auio, 0, ap->a_cred);
187 if (error == 0) {
188 readcnt = count - auio.uio_resid;
189 edp = (struct ext2_dir_entry_2 *)&dirbuf[readcnt];
190 ncookies = 0;
191 bzero(&dstdp, offsetof(struct dirent, d_name));
192 for (dp = (struct ext2_dir_entry_2 *)dirbuf;
193 !error && uio->uio_resid > 0 && dp < edp; ) {
194 /*-
195 * "New" ext2fs directory entries differ in 3 ways
196 * from ufs on-disk ones:
197 * - the name is not necessarily NUL-terminated.
198 * - the file type field always exists and always
199 * follows the name length field.
200 * - the file type is encoded in a different way.
201 *
202 * "Old" ext2fs directory entries need no special
203 * conversions, since they binary compatible with
204 * "new" entries having a file type of 0 (i.e.,
205 * EXT2_FT_UNKNOWN). Splitting the old name length
206 * field didn't make a mess like it did in ufs,
207 * because ext2fs uses a machine-dependent disk
208 * layout.
209 */
210 dstdp.d_fileno = dp->inode;
211 dstdp.d_type = FTTODT(dp->file_type);
212 dstdp.d_namlen = dp->name_len;
213 dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp);
214 bcopy(dp->name, dstdp.d_name, dstdp.d_namlen);
215 bzero(dstdp.d_name + dstdp.d_namlen,
216 dstdp.d_reclen - offsetof(struct dirent, d_name) -
217 dstdp.d_namlen);
218
219 if (dp->rec_len > 0) {
220 if(dstdp.d_reclen <= uio->uio_resid) {
221 /* advance dp */
222 dp = (struct ext2_dir_entry_2 *)
223 ((char *)dp + dp->rec_len);
224 error =
|
227 if (!error)
228 ncookies++;
229 } else
230 break;
231 } else {
232 error = EIO;
233 break;
234 }
235 }
236 /* we need to correct uio_offset */
237 uio->uio_offset = startoffset + (caddr_t)dp - dirbuf;
238
239 if (!error && ap->a_ncookies != NULL) {
240 u_long *cookiep, *cookies, *ecookies;
241 off_t off;
242
243 if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
244 panic("ext2fs_readdir: unexpected uio from NFS server");
245 MALLOC(cookies, u_long *, ncookies * sizeof(u_long), M_TEMP,
246 M_WAITOK);
247 off = startoffset;
248 for (dp = (struct ext2_dir_entry_2 *)dirbuf,
249 cookiep = cookies, ecookies = cookies + ncookies;
250 cookiep < ecookies;
251 dp = (struct ext2_dir_entry_2 *)((caddr_t) dp + dp->rec_len)) {
252 off += dp->rec_len;
253 *cookiep++ = (u_long) off;
254 }
255 *ap->a_ncookies = ncookies;
256 *ap->a_cookies = cookies;
257 }
258 }
259 FREE(dirbuf, M_TEMP);
260 if (ap->a_eofflag)
261 *ap->a_eofflag = VTOI(ap->a_vp)->i_size <= uio->uio_offset;
262 return (error);
263}
264
265/*
266 * Convert a component of a pathname into a pointer to a locked inode.
267 * This is a very central and rather complicated routine.
268 * If the file system is not maintained in a strict tree hierarchy,
269 * this can result in a deadlock situation (see comments in code below).
270 *
271 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
272 * on whether the name is to be looked up, created, renamed, or deleted.
273 * When CREATE, RENAME, or DELETE is specified, information usable in
274 * creating, renaming, or deleting a directory entry may be calculated.
275 * If flag has LOCKPARENT or'ed into it and the target of the pathname
276 * exists, lookup returns both the target and its parent directory locked.
277 * When creating or renaming and LOCKPARENT is specified, the target may
278 * not be ".". When deleting and LOCKPARENT is specified, the target may
279 * be "."., but the caller must check to ensure it does an vrele and vput
280 * instead of two vputs.
281 *
282 * Overall outline of ufs_lookup:
283 *
284 * search for name in directory, to found or notfound
285 * notfound:
286 * if creating, return locked directory, leaving info on available slots
287 * else return error
288 * found:
289 * if at end of path and deleting, return information to allow delete
290 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
291 * inode and return info to allow rewrite
292 * if not at end, add name to cache; if at end and neither creating
293 * nor deleting, add name to cache
294 */
295int
296ext2_lookup(ap)
297 struct vop_cachedlookup_args /* {
298 struct vnode *a_dvp;
299 struct vnode **a_vpp;
300 struct componentname *a_cnp;
301 } */ *ap;
302{
303 struct vnode *vdp; /* vnode for directory being searched */
304 struct inode *dp; /* inode for directory being searched */
305 struct buf *bp; /* a buffer of directory entries */
306 struct ext2_dir_entry_2 *ep; /* the current directory entry */
307 int entryoffsetinblock; /* offset of ep in bp's buffer */
308 enum {NONE, COMPACT, FOUND} slotstatus;
309 doff_t slotoffset; /* offset of area with free space */
310 int slotsize; /* size of area at slotoffset */
311 int slotfreespace; /* amount of space free in slot */
312 int slotneeded; /* size of the entry we're seeking */
313 int numdirpasses; /* strategy for directory search */
314 doff_t endsearch; /* offset to end directory search */
315 doff_t prevoff; /* prev entry dp->i_offset */
316 struct vnode *pdp; /* saved dp during symlink work */
317 struct vnode *tdp; /* returned by VFS_VGET */
318 doff_t enduseful; /* pointer past last used dir slot */
319 u_long bmask; /* block offset mask */
320 int lockparent; /* 1 => lockparent flag is set */
321 int wantparent; /* 1 => wantparent or lockparent flag */
322 int namlen, error;
323 struct vnode **vpp = ap->a_vpp;
324 struct componentname *cnp = ap->a_cnp;
325 struct ucred *cred = cnp->cn_cred;
326 int flags = cnp->cn_flags;
327 int nameiop = cnp->cn_nameiop;
328 struct thread *td = cnp->cn_thread;
329
330 int DIRBLKSIZ = VTOI(ap->a_dvp)->i_e2fs->s_blocksize;
331
332 bp = NULL;
333 slotoffset = -1;
334 *vpp = NULL;
335 vdp = ap->a_dvp;
336 dp = VTOI(vdp);
337 lockparent = flags & LOCKPARENT;
338 wantparent = flags & (LOCKPARENT|WANTPARENT);
339
340 /*
341 * We now have a segment name to search for, and a directory to search.
342 */
343
344 /*
345 * Suppress search for slots unless creating
346 * file and at end of pathname, in which case
347 * we watch for a place to put the new file in
348 * case it doesn't already exist.
349 */
350 slotstatus = FOUND;
351 slotfreespace = slotsize = slotneeded = 0;
352 if ((nameiop == CREATE || nameiop == RENAME) &&
353 (flags & ISLASTCN)) {
354 slotstatus = NONE;
355 slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen);
356 /* was
357 slotneeded = (sizeof(struct direct) - MAXNAMLEN +
358 cnp->cn_namelen + 3) &~ 3; */
359 }
360
361 /*
362 * If there is cached information on a previous search of
363 * this directory, pick up where we last left off.
364 * We cache only lookups as these are the most common
365 * and have the greatest payoff. Caching CREATE has little
366 * benefit as it usually must search the entire directory
367 * to determine that the entry does not exist. Caching the
368 * location of the last DELETE or RENAME has not reduced
369 * profiling time and hence has been removed in the interest
370 * of simplicity.
371 */
372 bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
373 if (nameiop != LOOKUP || dp->i_diroff == 0 ||
374 dp->i_diroff > dp->i_size) {
375 entryoffsetinblock = 0;
376 dp->i_offset = 0;
377 numdirpasses = 1;
378 } else {
379 dp->i_offset = dp->i_diroff;
380 if ((entryoffsetinblock = dp->i_offset & bmask) &&
381 (error = ext2_blkatoff(vdp, (off_t)dp->i_offset, NULL,
382 &bp)))
383 return (error);
384 numdirpasses = 2;
385 nchstats.ncs_2passes++;
386 }
387 prevoff = dp->i_offset;
388 endsearch = roundup(dp->i_size, DIRBLKSIZ);
389 enduseful = 0;
390
391searchloop:
392 while (dp->i_offset < endsearch) {
393 /*
394 * If necessary, get the next directory block.
395 */
396 if ((dp->i_offset & bmask) == 0) {
397 if (bp != NULL)
398 brelse(bp);
399 if ((error =
400 ext2_blkatoff(vdp, (off_t)dp->i_offset, NULL,
401 &bp)) != 0)
402 return (error);
403 entryoffsetinblock = 0;
404 }
405 /*
406 * If still looking for a slot, and at a DIRBLKSIZE
407 * boundary, have to start looking for free space again.
408 */
409 if (slotstatus == NONE &&
410 (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) {
411 slotoffset = -1;
412 slotfreespace = 0;
413 }
414 /*
415 * Get pointer to next entry.
416 * Full validation checks are slow, so we only check
417 * enough to insure forward progress through the
418 * directory. Complete checks can be run by setting
419 * "vfs.e2fs.dirchk" to be true.
420 */
421 ep = (struct ext2_dir_entry_2 *)
422 ((char *)bp->b_data + entryoffsetinblock);
423 if (ep->rec_len == 0 ||
424 (dirchk && ext2_dirbadentry(vdp, ep, entryoffsetinblock))) {
425 int i;
426 ext2_dirbad(dp, dp->i_offset, "mangled entry");
427 i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
428 dp->i_offset += i;
429 entryoffsetinblock += i;
430 continue;
431 }
432
433 /*
434 * If an appropriate sized slot has not yet been found,
435 * check to see if one is available. Also accumulate space
436 * in the current block so that we can determine if
437 * compaction is viable.
438 */
439 if (slotstatus != FOUND) {
440 int size = ep->rec_len;
441
442 if (ep->inode != 0)
443 size -= EXT2_DIR_REC_LEN(ep->name_len);
444 if (size > 0) {
445 if (size >= slotneeded) {
446 slotstatus = FOUND;
447 slotoffset = dp->i_offset;
448 slotsize = ep->rec_len;
449 } else if (slotstatus == NONE) {
450 slotfreespace += size;
451 if (slotoffset == -1)
452 slotoffset = dp->i_offset;
453 if (slotfreespace >= slotneeded) {
454 slotstatus = COMPACT;
455 slotsize = dp->i_offset +
456 ep->rec_len - slotoffset;
457 }
458 }
459 }
460 }
461
462 /*
463 * Check for a name match.
464 */
465 if (ep->inode) {
466 namlen = ep->name_len;
467 if (namlen == cnp->cn_namelen &&
468 !bcmp(cnp->cn_nameptr, ep->name,
469 (unsigned)namlen)) {
470 /*
471 * Save directory entry's inode number and
472 * reclen in ndp->ni_ufs area, and release
473 * directory buffer.
474 */
475 dp->i_ino = ep->inode;
476 dp->i_reclen = ep->rec_len;
477 goto found;
478 }
479 }
480 prevoff = dp->i_offset;
481 dp->i_offset += ep->rec_len;
482 entryoffsetinblock += ep->rec_len;
483 if (ep->inode)
484 enduseful = dp->i_offset;
485 }
486/* notfound: */
487 /*
488 * If we started in the middle of the directory and failed
489 * to find our target, we must check the beginning as well.
490 */
491 if (numdirpasses == 2) {
492 numdirpasses--;
493 dp->i_offset = 0;
494 endsearch = dp->i_diroff;
495 goto searchloop;
496 }
497 if (bp != NULL)
498 brelse(bp);
499 /*
500 * If creating, and at end of pathname and current
501 * directory has not been removed, then can consider
502 * allowing file to be created.
503 */
504 if ((nameiop == CREATE || nameiop == RENAME) &&
505 (flags & ISLASTCN) && dp->i_nlink != 0) {
506 /*
507 * Access for write is interpreted as allowing
508 * creation of files in the directory.
509 */
510 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0)
511 return (error);
512 /*
513 * Return an indication of where the new directory
514 * entry should be put. If we didn't find a slot,
515 * then set dp->i_count to 0 indicating
516 * that the new slot belongs at the end of the
517 * directory. If we found a slot, then the new entry
518 * can be put in the range from dp->i_offset to
519 * dp->i_offset + dp->i_count.
520 */
521 if (slotstatus == NONE) {
522 dp->i_offset = roundup(dp->i_size, DIRBLKSIZ);
523 dp->i_count = 0;
524 enduseful = dp->i_offset;
525 } else {
526 dp->i_offset = slotoffset;
527 dp->i_count = slotsize;
528 if (enduseful < slotoffset + slotsize)
529 enduseful = slotoffset + slotsize;
530 }
531 dp->i_endoff = roundup(enduseful, DIRBLKSIZ);
532 dp->i_flag |= IN_CHANGE | IN_UPDATE;
533 /*
534 * We return with the directory locked, so that
535 * the parameters we set up above will still be
536 * valid if we actually decide to do a direnter().
537 * We return ni_vp == NULL to indicate that the entry
538 * does not currently exist; we leave a pointer to
539 * the (locked) directory inode in ndp->ni_dvp.
540 * The pathname buffer is saved so that the name
541 * can be obtained later.
542 *
543 * NB - if the directory is unlocked, then this
544 * information cannot be used.
545 */
546 cnp->cn_flags |= SAVENAME;
547 if (!lockparent)
548 VOP_UNLOCK(vdp, 0, td);
549 return (EJUSTRETURN);
550 }
551 /*
552 * Insert name into cache (as non-existent) if appropriate.
553 */
554 if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE)
555 cache_enter(vdp, *vpp, cnp);
556 return (ENOENT);
557
558found:
559 if (numdirpasses == 2)
560 nchstats.ncs_pass2++;
561 /*
562 * Check that directory length properly reflects presence
563 * of this entry.
564 */
565 if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->name_len)
566 > dp->i_size) {
567 ext2_dirbad(dp, dp->i_offset, "i_size too small");
568 dp->i_size = entryoffsetinblock+EXT2_DIR_REC_LEN(ep->name_len);
569 dp->i_flag |= IN_CHANGE | IN_UPDATE;
570 }
571 brelse(bp);
572
573 /*
574 * Found component in pathname.
575 * If the final component of path name, save information
576 * in the cache as to where the entry was found.
577 */
578 if ((flags & ISLASTCN) && nameiop == LOOKUP)
579 dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1);
580
581 /*
582 * If deleting, and at end of pathname, return
583 * parameters which can be used to remove file.
584 * If the wantparent flag isn't set, we return only
585 * the directory (in ndp->ni_dvp), otherwise we go
586 * on and lock the inode, being careful with ".".
587 */
588 if (nameiop == DELETE && (flags & ISLASTCN)) {
589 /*
590 * Write access to directory required to delete files.
591 */
592 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0)
593 return (error);
594 /*
595 * Return pointer to current entry in dp->i_offset,
596 * and distance past previous entry (if there
597 * is a previous entry in this block) in dp->i_count.
598 * Save directory inode pointer in ndp->ni_dvp for dirremove().
599 */
600 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
601 dp->i_count = 0;
602 else
603 dp->i_count = dp->i_offset - prevoff;
604 if (dp->i_number == dp->i_ino) {
605 VREF(vdp);
606 *vpp = vdp;
607 return (0);
608 }
609 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE,
610 &tdp)) != 0)
611 return (error);
612 /*
613 * If directory is "sticky", then user must own
614 * the directory, or the file in it, else she
615 * may not delete it (unless she's root). This
616 * implements append-only directories.
617 */
618 if ((dp->i_mode & ISVTX) &&
619 cred->cr_uid != 0 &&
620 cred->cr_uid != dp->i_uid &&
621 VTOI(tdp)->i_uid != cred->cr_uid) {
622 vput(tdp);
623 return (EPERM);
624 }
625 *vpp = tdp;
626 if (!lockparent)
627 VOP_UNLOCK(vdp, 0, td);
628 return (0);
629 }
630
631 /*
632 * If rewriting (RENAME), return the inode and the
633 * information required to rewrite the present directory
634 * Must get inode of directory entry to verify it's a
635 * regular file, or empty directory.
636 */
637 if (nameiop == RENAME && wantparent &&
638 (flags & ISLASTCN)) {
639 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0)
640 return (error);
641 /*
642 * Careful about locking second inode.
643 * This can only occur if the target is ".".
644 */
645 if (dp->i_number == dp->i_ino)
646 return (EISDIR);
647 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE,
648 &tdp)) != 0)
649 return (error);
650 *vpp = tdp;
651 cnp->cn_flags |= SAVENAME;
652 if (!lockparent)
653 VOP_UNLOCK(vdp, 0, td);
654 return (0);
655 }
656
657 /*
658 * Step through the translation in the name. We do not `vput' the
659 * directory because we may need it again if a symbolic link
660 * is relative to the current directory. Instead we save it
661 * unlocked as "pdp". We must get the target inode before unlocking
662 * the directory to insure that the inode will not be removed
663 * before we get it. We prevent deadlock by always fetching
664 * inodes from the root, moving down the directory tree. Thus
665 * when following backward pointers ".." we must unlock the
666 * parent directory before getting the requested directory.
667 * There is a potential race condition here if both the current
668 * and parent directories are removed before the VFS_VGET for the
669 * inode associated with ".." returns. We hope that this occurs
670 * infrequently since we cannot avoid this race condition without
671 * implementing a sophisticated deadlock detection algorithm.
672 * Note also that this simple deadlock detection scheme will not
673 * work if the file system has any hard links other than ".."
674 * that point backwards in the directory structure.
675 */
676 pdp = vdp;
677 if (flags & ISDOTDOT) {
678 VOP_UNLOCK(pdp, 0, td); /* race to get the inode */
679 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE,
680 &tdp)) != 0) {
681 vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY, td);
682 return (error);
683 }
684 if (lockparent && (flags & ISLASTCN) &&
685 (error = vn_lock(pdp, LK_EXCLUSIVE, td))) {
686 vput(tdp);
687 return (error);
688 }
689 *vpp = tdp;
690 } else if (dp->i_number == dp->i_ino) {
691 VREF(vdp); /* we want ourself, ie "." */
692 *vpp = vdp;
693 } else {
694 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE,
695 &tdp)) != 0)
696 return (error);
697 if (!lockparent || !(flags & ISLASTCN))
698 VOP_UNLOCK(pdp, 0, td);
699 *vpp = tdp;
700 }
701
702 /*
703 * Insert name into cache if appropriate.
704 */
705 if (cnp->cn_flags & MAKEENTRY)
706 cache_enter(vdp, *vpp, cnp);
707 return (0);
708}
709
710void
711ext2_dirbad(ip, offset, how)
712 struct inode *ip;
713 doff_t offset;
714 char *how;
715{
716 struct mount *mp;
717
718 mp = ITOV(ip)->v_mount;
719 (void)printf("%s: bad dir ino %lu at offset %ld: %s\n",
720 mp->mnt_stat.f_mntonname, (u_long)ip->i_number, (long)offset, how);
721 if ((mp->mnt_flag & MNT_RDONLY) == 0)
722 panic("ext2_dirbad: bad dir");
723}
724
725/*
726 * Do consistency checking on a directory entry:
727 * record length must be multiple of 4
728 * entry must fit in rest of its DIRBLKSIZ block
729 * record must be large enough to contain entry
730 * name is not longer than MAXNAMLEN
731 * name must be as long as advertised, and null terminated
732 */
733/*
734 * changed so that it confirms to ext2_check_dir_entry
735 */
736static int
737ext2_dirbadentry(dp, de, entryoffsetinblock)
738 struct vnode *dp;
739 struct ext2_dir_entry_2 *de;
740 int entryoffsetinblock;
741{
742 int DIRBLKSIZ = VTOI(dp)->i_e2fs->s_blocksize;
743
744 char * error_msg = NULL;
745
746 if (de->rec_len < EXT2_DIR_REC_LEN(1))
747 error_msg = "rec_len is smaller than minimal";
748 else if (de->rec_len % 4 != 0)
749 error_msg = "rec_len % 4 != 0";
750 else if (de->rec_len < EXT2_DIR_REC_LEN(de->name_len))
751 error_msg = "reclen is too small for name_len";
752 else if (entryoffsetinblock + de->rec_len > DIRBLKSIZ)
753 error_msg = "directory entry across blocks";
754 /* else LATER
755 if (de->inode > dir->i_sb->u.ext2_sb.s_es->s_inodes_count)
756 error_msg = "inode out of bounds";
757 */
758
759 if (error_msg != NULL) {
760 printf("bad directory entry: %s\n", error_msg);
761 printf("offset=%d, inode=%lu, rec_len=%u, name_len=%u\n",
762 entryoffsetinblock, (unsigned long)de->inode,
763 de->rec_len, de->name_len);
764 }
765 return error_msg == NULL ? 0 : 1;
766}
767
768/*
769 * Write a directory entry after a call to namei, using the parameters
770 * that it left in nameidata. The argument ip is the inode which the new
771 * directory entry will refer to. Dvp is a pointer to the directory to
772 * be written, which was left locked by namei. Remaining parameters
773 * (dp->i_offset, dp->i_count) indicate how the space for the new
774 * entry is to be obtained.
775 */
776int
777ext2_direnter(ip, dvp, cnp)
778 struct inode *ip;
779 struct vnode *dvp;
780 struct componentname *cnp;
781{
782 struct ext2_dir_entry_2 *ep, *nep;
783 struct inode *dp;
784 struct buf *bp;
785 struct ext2_dir_entry_2 newdir;
786 struct iovec aiov;
787 struct uio auio;
788 u_int dsize;
789 int error, loc, newentrysize, spacefree;
790 char *dirbuf;
791 int DIRBLKSIZ = ip->i_e2fs->s_blocksize;
792
793
794#if DIAGNOSTIC
795 if ((cnp->cn_flags & SAVENAME) == 0)
796 panic("direnter: missing name");
797#endif
798 dp = VTOI(dvp);
799 newdir.inode = ip->i_number;
800 newdir.name_len = cnp->cn_namelen;
801 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
802 EXT2_FEATURE_INCOMPAT_FILETYPE))
803 newdir.file_type = DTTOFT(IFTODT(ip->i_mode));
804 else
805 newdir.file_type = EXT2_FT_UNKNOWN;
806 bcopy(cnp->cn_nameptr, newdir.name, (unsigned)cnp->cn_namelen + 1);
807 newentrysize = EXT2_DIR_REC_LEN(newdir.name_len);
808 if (dp->i_count == 0) {
809 /*
810 * If dp->i_count is 0, then namei could find no
811 * space in the directory. Here, dp->i_offset will
812 * be on a directory block boundary and we will write the
813 * new entry into a fresh block.
814 */
815 if (dp->i_offset & (DIRBLKSIZ - 1))
816 panic("ext2_direnter: newblk");
817 auio.uio_offset = dp->i_offset;
818 newdir.rec_len = DIRBLKSIZ;
819 auio.uio_resid = newentrysize;
820 aiov.iov_len = newentrysize;
821 aiov.iov_base = (caddr_t)&newdir;
822 auio.uio_iov = &aiov;
823 auio.uio_iovcnt = 1;
824 auio.uio_rw = UIO_WRITE;
825 auio.uio_segflg = UIO_SYSSPACE;
826 auio.uio_td = (struct thread *)0;
827 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred);
828 if (DIRBLKSIZ >
829 VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
830 /* XXX should grow with balloc() */
831 panic("ext2_direnter: frag size");
832 else if (!error) {
833 dp->i_size = roundup(dp->i_size, DIRBLKSIZ);
834 dp->i_flag |= IN_CHANGE;
835 }
836 return (error);
837 }
838
839 /*
840 * If dp->i_count is non-zero, then namei found space
841 * for the new entry in the range dp->i_offset to
842 * dp->i_offset + dp->i_count in the directory.
843 * To use this space, we may have to compact the entries located
844 * there, by copying them together towards the beginning of the
845 * block, leaving the free space in one usable chunk at the end.
846 */
847
848 /*
849 * Increase size of directory if entry eats into new space.
850 * This should never push the size past a new multiple of
851 * DIRBLKSIZE.
852 *
853 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
854 */
855 if (dp->i_offset + dp->i_count > dp->i_size)
856 dp->i_size = dp->i_offset + dp->i_count;
857 /*
858 * Get the block containing the space for the new directory entry.
859 */
860 if ((error = ext2_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf,
861 &bp)) != 0)
862 return (error);
863 /*
864 * Find space for the new entry. In the simple case, the entry at
865 * offset base will have the space. If it does not, then namei
866 * arranged that compacting the region dp->i_offset to
867 * dp->i_offset + dp->i_count would yield the
868 * space.
869 */
870 ep = (struct ext2_dir_entry_2 *)dirbuf;
871 dsize = EXT2_DIR_REC_LEN(ep->name_len);
872 spacefree = ep->rec_len - dsize;
873 for (loc = ep->rec_len; loc < dp->i_count; ) {
874 nep = (struct ext2_dir_entry_2 *)(dirbuf + loc);
875 if (ep->inode) {
876 /* trim the existing slot */
877 ep->rec_len = dsize;
878 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize);
879 } else {
880 /* overwrite; nothing there; header is ours */
881 spacefree += dsize;
882 }
883 dsize = EXT2_DIR_REC_LEN(nep->name_len);
884 spacefree += nep->rec_len - dsize;
885 loc += nep->rec_len;
886 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
887 }
888 /*
889 * Update the pointer fields in the previous entry (if any),
890 * copy in the new entry, and write out the block.
891 */
892 if (ep->inode == 0) {
893 if (spacefree + dsize < newentrysize)
894 panic("ext2_direnter: compact1");
895 newdir.rec_len = spacefree + dsize;
896 } else {
897 if (spacefree < newentrysize)
898 panic("ext2_direnter: compact2");
899 newdir.rec_len = spacefree;
900 ep->rec_len = dsize;
901 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize);
902 }
903 bcopy((caddr_t)&newdir, (caddr_t)ep, (u_int)newentrysize);
904 error = BUF_WRITE(bp);
905 dp->i_flag |= IN_CHANGE | IN_UPDATE;
906 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size)
907 error = ext2_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC,
908 cnp->cn_cred, cnp->cn_thread);
909 return (error);
910}
911
912/*
913 * Remove a directory entry after a call to namei, using
914 * the parameters which it left in nameidata. The entry
915 * dp->i_offset contains the offset into the directory of the
916 * entry to be eliminated. The dp->i_count field contains the
917 * size of the previous record in the directory. If this
918 * is 0, the first entry is being deleted, so we need only
919 * zero the inode number to mark the entry as free. If the
920 * entry is not the first in the directory, we must reclaim
921 * the space of the now empty record by adding the record size
922 * to the size of the previous entry.
923 */
924int
925ext2_dirremove(dvp, cnp)
926 struct vnode *dvp;
927 struct componentname *cnp;
928{
929 struct inode *dp;
930 struct ext2_dir_entry_2 *ep;
931 struct buf *bp;
932 int error;
933
934 dp = VTOI(dvp);
935 if (dp->i_count == 0) {
936 /*
937 * First entry in block: set d_ino to zero.
938 */
939 if ((error =
940 ext2_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep,
941 &bp)) != 0)
942 return (error);
943 ep->inode = 0;
944 error = BUF_WRITE(bp);
945 dp->i_flag |= IN_CHANGE | IN_UPDATE;
946 return (error);
947 }
948 /*
949 * Collapse new free space into previous entry.
950 */
951 if ((error = ext2_blkatoff(dvp, (off_t)(dp->i_offset - dp->i_count),
952 (char **)&ep, &bp)) != 0)
953 return (error);
954 ep->rec_len += dp->i_reclen;
955 error = BUF_WRITE(bp);
956 dp->i_flag |= IN_CHANGE | IN_UPDATE;
957 return (error);
958}
959
960/*
961 * Rewrite an existing directory entry to point at the inode
962 * supplied. The parameters describing the directory entry are
963 * set up by a call to namei.
964 */
965int
966ext2_dirrewrite(dp, ip, cnp)
967 struct inode *dp, *ip;
968 struct componentname *cnp;
969{
970 struct buf *bp;
971 struct ext2_dir_entry_2 *ep;
972 struct vnode *vdp = ITOV(dp);
973 int error;
974
975 if ((error = ext2_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep,
976 &bp)) != 0)
977 return (error);
978 ep->inode = ip->i_number;
979 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
980 EXT2_FEATURE_INCOMPAT_FILETYPE))
981 ep->file_type = DTTOFT(IFTODT(ip->i_mode));
982 else
983 ep->file_type = EXT2_FT_UNKNOWN;
984 error = BUF_WRITE(bp);
985 dp->i_flag |= IN_CHANGE | IN_UPDATE;
986 return (error);
987}
988
989/*
990 * Check if a directory is empty or not.
991 * Inode supplied must be locked.
992 *
993 * Using a struct dirtemplate here is not precisely
994 * what we want, but better than using a struct direct.
995 *
996 * NB: does not handle corrupted directories.
997 */
998int
999ext2_dirempty(ip, parentino, cred)
1000 struct inode *ip;
1001 ino_t parentino;
1002 struct ucred *cred;
1003{
1004 off_t off;
1005 struct dirtemplate dbuf;
1006 struct ext2_dir_entry_2 *dp = (struct ext2_dir_entry_2 *)&dbuf;
1007 int error, count, namlen;
1008
1009#define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
1010
1011 for (off = 0; off < ip->i_size; off += dp->rec_len) {
1012 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ,
1013 off, UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK, cred,
1014 NOCRED, &count, (struct thread *)0);
1015 /*
1016 * Since we read MINDIRSIZ, residual must
1017 * be 0 unless we're at end of file.
1018 */
1019 if (error || count != 0)
1020 return (0);
1021 /* avoid infinite loops */
1022 if (dp->rec_len == 0)
1023 return (0);
1024 /* skip empty entries */
1025 if (dp->inode == 0)
1026 continue;
1027 /* accept only "." and ".." */
1028 namlen = dp->name_len;
1029 if (namlen > 2)
1030 return (0);
1031 if (dp->name[0] != '.')
1032 return (0);
1033 /*
1034 * At this point namlen must be 1 or 2.
1035 * 1 implies ".", 2 implies ".." if second
1036 * char is also "."
1037 */
1038 if (namlen == 1)
1039 continue;
1040 if (dp->name[1] == '.' && dp->inode == parentino)
1041 continue;
1042 return (0);
1043 }
1044 return (1);
1045}
1046
1047/*
1048 * Check if source directory is in the path of the target directory.
1049 * Target is supplied locked, source is unlocked.
1050 * The target is always vput before returning.
1051 */
1052int
1053ext2_checkpath(source, target, cred)
1054 struct inode *source, *target;
1055 struct ucred *cred;
1056{
1057 struct vnode *vp;
1058 int error, rootino, namlen;
1059 struct dirtemplate dirbuf;
1060
1061 vp = ITOV(target);
1062 if (target->i_number == source->i_number) {
1063 error = EEXIST;
1064 goto out;
1065 }
1066 rootino = ROOTINO;
1067 error = 0;
1068 if (target->i_number == rootino)
1069 goto out;
1070
1071 for (;;) {
1072 if (vp->v_type != VDIR) {
1073 error = ENOTDIR;
1074 break;
1075 }
1076 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1077 sizeof (struct dirtemplate), (off_t)0, UIO_SYSSPACE,
1078 IO_NODELOCKED | IO_NOMACCHECK, cred, NOCRED, (int *)0,
1079 (struct thread *)0);
1080 if (error != 0)
1081 break;
1082 namlen = dirbuf.dotdot_type; /* like ufs little-endian */
1083 if (namlen != 2 ||
1084 dirbuf.dotdot_name[0] != '.' ||
1085 dirbuf.dotdot_name[1] != '.') {
1086 error = ENOTDIR;
1087 break;
1088 }
1089 if (dirbuf.dotdot_ino == source->i_number) {
1090 error = EINVAL;
1091 break;
1092 }
1093 if (dirbuf.dotdot_ino == rootino)
1094 break;
1095 vput(vp);
1096 if ((error = VFS_VGET(vp->v_mount, dirbuf.dotdot_ino,
1097 LK_EXCLUSIVE, &vp)) != 0) {
1098 vp = NULL;
1099 break;
1100 }
1101 }
1102
1103out:
1104 if (error == ENOTDIR)
1105 printf("checkpath: .. not a directory\n");
1106 if (vp != NULL)
1107 vput(vp);
1108 return (error);
1109}
1110
| 226 if (!error)
227 ncookies++;
228 } else
229 break;
230 } else {
231 error = EIO;
232 break;
233 }
234 }
235 /* we need to correct uio_offset */
236 uio->uio_offset = startoffset + (caddr_t)dp - dirbuf;
237
238 if (!error && ap->a_ncookies != NULL) {
239 u_long *cookiep, *cookies, *ecookies;
240 off_t off;
241
242 if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
243 panic("ext2fs_readdir: unexpected uio from NFS server");
244 MALLOC(cookies, u_long *, ncookies * sizeof(u_long), M_TEMP,
245 M_WAITOK);
246 off = startoffset;
247 for (dp = (struct ext2_dir_entry_2 *)dirbuf,
248 cookiep = cookies, ecookies = cookies + ncookies;
249 cookiep < ecookies;
250 dp = (struct ext2_dir_entry_2 *)((caddr_t) dp + dp->rec_len)) {
251 off += dp->rec_len;
252 *cookiep++ = (u_long) off;
253 }
254 *ap->a_ncookies = ncookies;
255 *ap->a_cookies = cookies;
256 }
257 }
258 FREE(dirbuf, M_TEMP);
259 if (ap->a_eofflag)
260 *ap->a_eofflag = VTOI(ap->a_vp)->i_size <= uio->uio_offset;
261 return (error);
262}
263
264/*
265 * Convert a component of a pathname into a pointer to a locked inode.
266 * This is a very central and rather complicated routine.
267 * If the file system is not maintained in a strict tree hierarchy,
268 * this can result in a deadlock situation (see comments in code below).
269 *
270 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
271 * on whether the name is to be looked up, created, renamed, or deleted.
272 * When CREATE, RENAME, or DELETE is specified, information usable in
273 * creating, renaming, or deleting a directory entry may be calculated.
274 * If flag has LOCKPARENT or'ed into it and the target of the pathname
275 * exists, lookup returns both the target and its parent directory locked.
276 * When creating or renaming and LOCKPARENT is specified, the target may
277 * not be ".". When deleting and LOCKPARENT is specified, the target may
278 * be "."., but the caller must check to ensure it does an vrele and vput
279 * instead of two vputs.
280 *
281 * Overall outline of ufs_lookup:
282 *
283 * search for name in directory, to found or notfound
284 * notfound:
285 * if creating, return locked directory, leaving info on available slots
286 * else return error
287 * found:
288 * if at end of path and deleting, return information to allow delete
289 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
290 * inode and return info to allow rewrite
291 * if not at end, add name to cache; if at end and neither creating
292 * nor deleting, add name to cache
293 */
294int
295ext2_lookup(ap)
296 struct vop_cachedlookup_args /* {
297 struct vnode *a_dvp;
298 struct vnode **a_vpp;
299 struct componentname *a_cnp;
300 } */ *ap;
301{
302 struct vnode *vdp; /* vnode for directory being searched */
303 struct inode *dp; /* inode for directory being searched */
304 struct buf *bp; /* a buffer of directory entries */
305 struct ext2_dir_entry_2 *ep; /* the current directory entry */
306 int entryoffsetinblock; /* offset of ep in bp's buffer */
307 enum {NONE, COMPACT, FOUND} slotstatus;
308 doff_t slotoffset; /* offset of area with free space */
309 int slotsize; /* size of area at slotoffset */
310 int slotfreespace; /* amount of space free in slot */
311 int slotneeded; /* size of the entry we're seeking */
312 int numdirpasses; /* strategy for directory search */
313 doff_t endsearch; /* offset to end directory search */
314 doff_t prevoff; /* prev entry dp->i_offset */
315 struct vnode *pdp; /* saved dp during symlink work */
316 struct vnode *tdp; /* returned by VFS_VGET */
317 doff_t enduseful; /* pointer past last used dir slot */
318 u_long bmask; /* block offset mask */
319 int lockparent; /* 1 => lockparent flag is set */
320 int wantparent; /* 1 => wantparent or lockparent flag */
321 int namlen, error;
322 struct vnode **vpp = ap->a_vpp;
323 struct componentname *cnp = ap->a_cnp;
324 struct ucred *cred = cnp->cn_cred;
325 int flags = cnp->cn_flags;
326 int nameiop = cnp->cn_nameiop;
327 struct thread *td = cnp->cn_thread;
328
329 int DIRBLKSIZ = VTOI(ap->a_dvp)->i_e2fs->s_blocksize;
330
331 bp = NULL;
332 slotoffset = -1;
333 *vpp = NULL;
334 vdp = ap->a_dvp;
335 dp = VTOI(vdp);
336 lockparent = flags & LOCKPARENT;
337 wantparent = flags & (LOCKPARENT|WANTPARENT);
338
339 /*
340 * We now have a segment name to search for, and a directory to search.
341 */
342
343 /*
344 * Suppress search for slots unless creating
345 * file and at end of pathname, in which case
346 * we watch for a place to put the new file in
347 * case it doesn't already exist.
348 */
349 slotstatus = FOUND;
350 slotfreespace = slotsize = slotneeded = 0;
351 if ((nameiop == CREATE || nameiop == RENAME) &&
352 (flags & ISLASTCN)) {
353 slotstatus = NONE;
354 slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen);
355 /* was
356 slotneeded = (sizeof(struct direct) - MAXNAMLEN +
357 cnp->cn_namelen + 3) &~ 3; */
358 }
359
360 /*
361 * If there is cached information on a previous search of
362 * this directory, pick up where we last left off.
363 * We cache only lookups as these are the most common
364 * and have the greatest payoff. Caching CREATE has little
365 * benefit as it usually must search the entire directory
366 * to determine that the entry does not exist. Caching the
367 * location of the last DELETE or RENAME has not reduced
368 * profiling time and hence has been removed in the interest
369 * of simplicity.
370 */
371 bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
372 if (nameiop != LOOKUP || dp->i_diroff == 0 ||
373 dp->i_diroff > dp->i_size) {
374 entryoffsetinblock = 0;
375 dp->i_offset = 0;
376 numdirpasses = 1;
377 } else {
378 dp->i_offset = dp->i_diroff;
379 if ((entryoffsetinblock = dp->i_offset & bmask) &&
380 (error = ext2_blkatoff(vdp, (off_t)dp->i_offset, NULL,
381 &bp)))
382 return (error);
383 numdirpasses = 2;
384 nchstats.ncs_2passes++;
385 }
386 prevoff = dp->i_offset;
387 endsearch = roundup(dp->i_size, DIRBLKSIZ);
388 enduseful = 0;
389
390searchloop:
391 while (dp->i_offset < endsearch) {
392 /*
393 * If necessary, get the next directory block.
394 */
395 if ((dp->i_offset & bmask) == 0) {
396 if (bp != NULL)
397 brelse(bp);
398 if ((error =
399 ext2_blkatoff(vdp, (off_t)dp->i_offset, NULL,
400 &bp)) != 0)
401 return (error);
402 entryoffsetinblock = 0;
403 }
404 /*
405 * If still looking for a slot, and at a DIRBLKSIZE
406 * boundary, have to start looking for free space again.
407 */
408 if (slotstatus == NONE &&
409 (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) {
410 slotoffset = -1;
411 slotfreespace = 0;
412 }
413 /*
414 * Get pointer to next entry.
415 * Full validation checks are slow, so we only check
416 * enough to insure forward progress through the
417 * directory. Complete checks can be run by setting
418 * "vfs.e2fs.dirchk" to be true.
419 */
420 ep = (struct ext2_dir_entry_2 *)
421 ((char *)bp->b_data + entryoffsetinblock);
422 if (ep->rec_len == 0 ||
423 (dirchk && ext2_dirbadentry(vdp, ep, entryoffsetinblock))) {
424 int i;
425 ext2_dirbad(dp, dp->i_offset, "mangled entry");
426 i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
427 dp->i_offset += i;
428 entryoffsetinblock += i;
429 continue;
430 }
431
432 /*
433 * If an appropriate sized slot has not yet been found,
434 * check to see if one is available. Also accumulate space
435 * in the current block so that we can determine if
436 * compaction is viable.
437 */
438 if (slotstatus != FOUND) {
439 int size = ep->rec_len;
440
441 if (ep->inode != 0)
442 size -= EXT2_DIR_REC_LEN(ep->name_len);
443 if (size > 0) {
444 if (size >= slotneeded) {
445 slotstatus = FOUND;
446 slotoffset = dp->i_offset;
447 slotsize = ep->rec_len;
448 } else if (slotstatus == NONE) {
449 slotfreespace += size;
450 if (slotoffset == -1)
451 slotoffset = dp->i_offset;
452 if (slotfreespace >= slotneeded) {
453 slotstatus = COMPACT;
454 slotsize = dp->i_offset +
455 ep->rec_len - slotoffset;
456 }
457 }
458 }
459 }
460
461 /*
462 * Check for a name match.
463 */
464 if (ep->inode) {
465 namlen = ep->name_len;
466 if (namlen == cnp->cn_namelen &&
467 !bcmp(cnp->cn_nameptr, ep->name,
468 (unsigned)namlen)) {
469 /*
470 * Save directory entry's inode number and
471 * reclen in ndp->ni_ufs area, and release
472 * directory buffer.
473 */
474 dp->i_ino = ep->inode;
475 dp->i_reclen = ep->rec_len;
476 goto found;
477 }
478 }
479 prevoff = dp->i_offset;
480 dp->i_offset += ep->rec_len;
481 entryoffsetinblock += ep->rec_len;
482 if (ep->inode)
483 enduseful = dp->i_offset;
484 }
485/* notfound: */
486 /*
487 * If we started in the middle of the directory and failed
488 * to find our target, we must check the beginning as well.
489 */
490 if (numdirpasses == 2) {
491 numdirpasses--;
492 dp->i_offset = 0;
493 endsearch = dp->i_diroff;
494 goto searchloop;
495 }
496 if (bp != NULL)
497 brelse(bp);
498 /*
499 * If creating, and at end of pathname and current
500 * directory has not been removed, then can consider
501 * allowing file to be created.
502 */
503 if ((nameiop == CREATE || nameiop == RENAME) &&
504 (flags & ISLASTCN) && dp->i_nlink != 0) {
505 /*
506 * Access for write is interpreted as allowing
507 * creation of files in the directory.
508 */
509 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0)
510 return (error);
511 /*
512 * Return an indication of where the new directory
513 * entry should be put. If we didn't find a slot,
514 * then set dp->i_count to 0 indicating
515 * that the new slot belongs at the end of the
516 * directory. If we found a slot, then the new entry
517 * can be put in the range from dp->i_offset to
518 * dp->i_offset + dp->i_count.
519 */
520 if (slotstatus == NONE) {
521 dp->i_offset = roundup(dp->i_size, DIRBLKSIZ);
522 dp->i_count = 0;
523 enduseful = dp->i_offset;
524 } else {
525 dp->i_offset = slotoffset;
526 dp->i_count = slotsize;
527 if (enduseful < slotoffset + slotsize)
528 enduseful = slotoffset + slotsize;
529 }
530 dp->i_endoff = roundup(enduseful, DIRBLKSIZ);
531 dp->i_flag |= IN_CHANGE | IN_UPDATE;
532 /*
533 * We return with the directory locked, so that
534 * the parameters we set up above will still be
535 * valid if we actually decide to do a direnter().
536 * We return ni_vp == NULL to indicate that the entry
537 * does not currently exist; we leave a pointer to
538 * the (locked) directory inode in ndp->ni_dvp.
539 * The pathname buffer is saved so that the name
540 * can be obtained later.
541 *
542 * NB - if the directory is unlocked, then this
543 * information cannot be used.
544 */
545 cnp->cn_flags |= SAVENAME;
546 if (!lockparent)
547 VOP_UNLOCK(vdp, 0, td);
548 return (EJUSTRETURN);
549 }
550 /*
551 * Insert name into cache (as non-existent) if appropriate.
552 */
553 if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE)
554 cache_enter(vdp, *vpp, cnp);
555 return (ENOENT);
556
557found:
558 if (numdirpasses == 2)
559 nchstats.ncs_pass2++;
560 /*
561 * Check that directory length properly reflects presence
562 * of this entry.
563 */
564 if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->name_len)
565 > dp->i_size) {
566 ext2_dirbad(dp, dp->i_offset, "i_size too small");
567 dp->i_size = entryoffsetinblock+EXT2_DIR_REC_LEN(ep->name_len);
568 dp->i_flag |= IN_CHANGE | IN_UPDATE;
569 }
570 brelse(bp);
571
572 /*
573 * Found component in pathname.
574 * If the final component of path name, save information
575 * in the cache as to where the entry was found.
576 */
577 if ((flags & ISLASTCN) && nameiop == LOOKUP)
578 dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1);
579
580 /*
581 * If deleting, and at end of pathname, return
582 * parameters which can be used to remove file.
583 * If the wantparent flag isn't set, we return only
584 * the directory (in ndp->ni_dvp), otherwise we go
585 * on and lock the inode, being careful with ".".
586 */
587 if (nameiop == DELETE && (flags & ISLASTCN)) {
588 /*
589 * Write access to directory required to delete files.
590 */
591 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0)
592 return (error);
593 /*
594 * Return pointer to current entry in dp->i_offset,
595 * and distance past previous entry (if there
596 * is a previous entry in this block) in dp->i_count.
597 * Save directory inode pointer in ndp->ni_dvp for dirremove().
598 */
599 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
600 dp->i_count = 0;
601 else
602 dp->i_count = dp->i_offset - prevoff;
603 if (dp->i_number == dp->i_ino) {
604 VREF(vdp);
605 *vpp = vdp;
606 return (0);
607 }
608 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE,
609 &tdp)) != 0)
610 return (error);
611 /*
612 * If directory is "sticky", then user must own
613 * the directory, or the file in it, else she
614 * may not delete it (unless she's root). This
615 * implements append-only directories.
616 */
617 if ((dp->i_mode & ISVTX) &&
618 cred->cr_uid != 0 &&
619 cred->cr_uid != dp->i_uid &&
620 VTOI(tdp)->i_uid != cred->cr_uid) {
621 vput(tdp);
622 return (EPERM);
623 }
624 *vpp = tdp;
625 if (!lockparent)
626 VOP_UNLOCK(vdp, 0, td);
627 return (0);
628 }
629
630 /*
631 * If rewriting (RENAME), return the inode and the
632 * information required to rewrite the present directory
633 * Must get inode of directory entry to verify it's a
634 * regular file, or empty directory.
635 */
636 if (nameiop == RENAME && wantparent &&
637 (flags & ISLASTCN)) {
638 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0)
639 return (error);
640 /*
641 * Careful about locking second inode.
642 * This can only occur if the target is ".".
643 */
644 if (dp->i_number == dp->i_ino)
645 return (EISDIR);
646 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE,
647 &tdp)) != 0)
648 return (error);
649 *vpp = tdp;
650 cnp->cn_flags |= SAVENAME;
651 if (!lockparent)
652 VOP_UNLOCK(vdp, 0, td);
653 return (0);
654 }
655
656 /*
657 * Step through the translation in the name. We do not `vput' the
658 * directory because we may need it again if a symbolic link
659 * is relative to the current directory. Instead we save it
660 * unlocked as "pdp". We must get the target inode before unlocking
661 * the directory to insure that the inode will not be removed
662 * before we get it. We prevent deadlock by always fetching
663 * inodes from the root, moving down the directory tree. Thus
664 * when following backward pointers ".." we must unlock the
665 * parent directory before getting the requested directory.
666 * There is a potential race condition here if both the current
667 * and parent directories are removed before the VFS_VGET for the
668 * inode associated with ".." returns. We hope that this occurs
669 * infrequently since we cannot avoid this race condition without
670 * implementing a sophisticated deadlock detection algorithm.
671 * Note also that this simple deadlock detection scheme will not
672 * work if the file system has any hard links other than ".."
673 * that point backwards in the directory structure.
674 */
675 pdp = vdp;
676 if (flags & ISDOTDOT) {
677 VOP_UNLOCK(pdp, 0, td); /* race to get the inode */
678 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE,
679 &tdp)) != 0) {
680 vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY, td);
681 return (error);
682 }
683 if (lockparent && (flags & ISLASTCN) &&
684 (error = vn_lock(pdp, LK_EXCLUSIVE, td))) {
685 vput(tdp);
686 return (error);
687 }
688 *vpp = tdp;
689 } else if (dp->i_number == dp->i_ino) {
690 VREF(vdp); /* we want ourself, ie "." */
691 *vpp = vdp;
692 } else {
693 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE,
694 &tdp)) != 0)
695 return (error);
696 if (!lockparent || !(flags & ISLASTCN))
697 VOP_UNLOCK(pdp, 0, td);
698 *vpp = tdp;
699 }
700
701 /*
702 * Insert name into cache if appropriate.
703 */
704 if (cnp->cn_flags & MAKEENTRY)
705 cache_enter(vdp, *vpp, cnp);
706 return (0);
707}
708
709void
710ext2_dirbad(ip, offset, how)
711 struct inode *ip;
712 doff_t offset;
713 char *how;
714{
715 struct mount *mp;
716
717 mp = ITOV(ip)->v_mount;
718 (void)printf("%s: bad dir ino %lu at offset %ld: %s\n",
719 mp->mnt_stat.f_mntonname, (u_long)ip->i_number, (long)offset, how);
720 if ((mp->mnt_flag & MNT_RDONLY) == 0)
721 panic("ext2_dirbad: bad dir");
722}
723
724/*
725 * Do consistency checking on a directory entry:
726 * record length must be multiple of 4
727 * entry must fit in rest of its DIRBLKSIZ block
728 * record must be large enough to contain entry
729 * name is not longer than MAXNAMLEN
730 * name must be as long as advertised, and null terminated
731 */
732/*
733 * changed so that it confirms to ext2_check_dir_entry
734 */
735static int
736ext2_dirbadentry(dp, de, entryoffsetinblock)
737 struct vnode *dp;
738 struct ext2_dir_entry_2 *de;
739 int entryoffsetinblock;
740{
741 int DIRBLKSIZ = VTOI(dp)->i_e2fs->s_blocksize;
742
743 char * error_msg = NULL;
744
745 if (de->rec_len < EXT2_DIR_REC_LEN(1))
746 error_msg = "rec_len is smaller than minimal";
747 else if (de->rec_len % 4 != 0)
748 error_msg = "rec_len % 4 != 0";
749 else if (de->rec_len < EXT2_DIR_REC_LEN(de->name_len))
750 error_msg = "reclen is too small for name_len";
751 else if (entryoffsetinblock + de->rec_len > DIRBLKSIZ)
752 error_msg = "directory entry across blocks";
753 /* else LATER
754 if (de->inode > dir->i_sb->u.ext2_sb.s_es->s_inodes_count)
755 error_msg = "inode out of bounds";
756 */
757
758 if (error_msg != NULL) {
759 printf("bad directory entry: %s\n", error_msg);
760 printf("offset=%d, inode=%lu, rec_len=%u, name_len=%u\n",
761 entryoffsetinblock, (unsigned long)de->inode,
762 de->rec_len, de->name_len);
763 }
764 return error_msg == NULL ? 0 : 1;
765}
766
767/*
768 * Write a directory entry after a call to namei, using the parameters
769 * that it left in nameidata. The argument ip is the inode which the new
770 * directory entry will refer to. Dvp is a pointer to the directory to
771 * be written, which was left locked by namei. Remaining parameters
772 * (dp->i_offset, dp->i_count) indicate how the space for the new
773 * entry is to be obtained.
774 */
775int
776ext2_direnter(ip, dvp, cnp)
777 struct inode *ip;
778 struct vnode *dvp;
779 struct componentname *cnp;
780{
781 struct ext2_dir_entry_2 *ep, *nep;
782 struct inode *dp;
783 struct buf *bp;
784 struct ext2_dir_entry_2 newdir;
785 struct iovec aiov;
786 struct uio auio;
787 u_int dsize;
788 int error, loc, newentrysize, spacefree;
789 char *dirbuf;
790 int DIRBLKSIZ = ip->i_e2fs->s_blocksize;
791
792
793#if DIAGNOSTIC
794 if ((cnp->cn_flags & SAVENAME) == 0)
795 panic("direnter: missing name");
796#endif
797 dp = VTOI(dvp);
798 newdir.inode = ip->i_number;
799 newdir.name_len = cnp->cn_namelen;
800 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
801 EXT2_FEATURE_INCOMPAT_FILETYPE))
802 newdir.file_type = DTTOFT(IFTODT(ip->i_mode));
803 else
804 newdir.file_type = EXT2_FT_UNKNOWN;
805 bcopy(cnp->cn_nameptr, newdir.name, (unsigned)cnp->cn_namelen + 1);
806 newentrysize = EXT2_DIR_REC_LEN(newdir.name_len);
807 if (dp->i_count == 0) {
808 /*
809 * If dp->i_count is 0, then namei could find no
810 * space in the directory. Here, dp->i_offset will
811 * be on a directory block boundary and we will write the
812 * new entry into a fresh block.
813 */
814 if (dp->i_offset & (DIRBLKSIZ - 1))
815 panic("ext2_direnter: newblk");
816 auio.uio_offset = dp->i_offset;
817 newdir.rec_len = DIRBLKSIZ;
818 auio.uio_resid = newentrysize;
819 aiov.iov_len = newentrysize;
820 aiov.iov_base = (caddr_t)&newdir;
821 auio.uio_iov = &aiov;
822 auio.uio_iovcnt = 1;
823 auio.uio_rw = UIO_WRITE;
824 auio.uio_segflg = UIO_SYSSPACE;
825 auio.uio_td = (struct thread *)0;
826 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred);
827 if (DIRBLKSIZ >
828 VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
829 /* XXX should grow with balloc() */
830 panic("ext2_direnter: frag size");
831 else if (!error) {
832 dp->i_size = roundup(dp->i_size, DIRBLKSIZ);
833 dp->i_flag |= IN_CHANGE;
834 }
835 return (error);
836 }
837
838 /*
839 * If dp->i_count is non-zero, then namei found space
840 * for the new entry in the range dp->i_offset to
841 * dp->i_offset + dp->i_count in the directory.
842 * To use this space, we may have to compact the entries located
843 * there, by copying them together towards the beginning of the
844 * block, leaving the free space in one usable chunk at the end.
845 */
846
847 /*
848 * Increase size of directory if entry eats into new space.
849 * This should never push the size past a new multiple of
850 * DIRBLKSIZE.
851 *
852 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
853 */
854 if (dp->i_offset + dp->i_count > dp->i_size)
855 dp->i_size = dp->i_offset + dp->i_count;
856 /*
857 * Get the block containing the space for the new directory entry.
858 */
859 if ((error = ext2_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf,
860 &bp)) != 0)
861 return (error);
862 /*
863 * Find space for the new entry. In the simple case, the entry at
864 * offset base will have the space. If it does not, then namei
865 * arranged that compacting the region dp->i_offset to
866 * dp->i_offset + dp->i_count would yield the
867 * space.
868 */
869 ep = (struct ext2_dir_entry_2 *)dirbuf;
870 dsize = EXT2_DIR_REC_LEN(ep->name_len);
871 spacefree = ep->rec_len - dsize;
872 for (loc = ep->rec_len; loc < dp->i_count; ) {
873 nep = (struct ext2_dir_entry_2 *)(dirbuf + loc);
874 if (ep->inode) {
875 /* trim the existing slot */
876 ep->rec_len = dsize;
877 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize);
878 } else {
879 /* overwrite; nothing there; header is ours */
880 spacefree += dsize;
881 }
882 dsize = EXT2_DIR_REC_LEN(nep->name_len);
883 spacefree += nep->rec_len - dsize;
884 loc += nep->rec_len;
885 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
886 }
887 /*
888 * Update the pointer fields in the previous entry (if any),
889 * copy in the new entry, and write out the block.
890 */
891 if (ep->inode == 0) {
892 if (spacefree + dsize < newentrysize)
893 panic("ext2_direnter: compact1");
894 newdir.rec_len = spacefree + dsize;
895 } else {
896 if (spacefree < newentrysize)
897 panic("ext2_direnter: compact2");
898 newdir.rec_len = spacefree;
899 ep->rec_len = dsize;
900 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize);
901 }
902 bcopy((caddr_t)&newdir, (caddr_t)ep, (u_int)newentrysize);
903 error = BUF_WRITE(bp);
904 dp->i_flag |= IN_CHANGE | IN_UPDATE;
905 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size)
906 error = ext2_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC,
907 cnp->cn_cred, cnp->cn_thread);
908 return (error);
909}
910
911/*
912 * Remove a directory entry after a call to namei, using
913 * the parameters which it left in nameidata. The entry
914 * dp->i_offset contains the offset into the directory of the
915 * entry to be eliminated. The dp->i_count field contains the
916 * size of the previous record in the directory. If this
917 * is 0, the first entry is being deleted, so we need only
918 * zero the inode number to mark the entry as free. If the
919 * entry is not the first in the directory, we must reclaim
920 * the space of the now empty record by adding the record size
921 * to the size of the previous entry.
922 */
923int
924ext2_dirremove(dvp, cnp)
925 struct vnode *dvp;
926 struct componentname *cnp;
927{
928 struct inode *dp;
929 struct ext2_dir_entry_2 *ep;
930 struct buf *bp;
931 int error;
932
933 dp = VTOI(dvp);
934 if (dp->i_count == 0) {
935 /*
936 * First entry in block: set d_ino to zero.
937 */
938 if ((error =
939 ext2_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep,
940 &bp)) != 0)
941 return (error);
942 ep->inode = 0;
943 error = BUF_WRITE(bp);
944 dp->i_flag |= IN_CHANGE | IN_UPDATE;
945 return (error);
946 }
947 /*
948 * Collapse new free space into previous entry.
949 */
950 if ((error = ext2_blkatoff(dvp, (off_t)(dp->i_offset - dp->i_count),
951 (char **)&ep, &bp)) != 0)
952 return (error);
953 ep->rec_len += dp->i_reclen;
954 error = BUF_WRITE(bp);
955 dp->i_flag |= IN_CHANGE | IN_UPDATE;
956 return (error);
957}
958
959/*
960 * Rewrite an existing directory entry to point at the inode
961 * supplied. The parameters describing the directory entry are
962 * set up by a call to namei.
963 */
964int
965ext2_dirrewrite(dp, ip, cnp)
966 struct inode *dp, *ip;
967 struct componentname *cnp;
968{
969 struct buf *bp;
970 struct ext2_dir_entry_2 *ep;
971 struct vnode *vdp = ITOV(dp);
972 int error;
973
974 if ((error = ext2_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep,
975 &bp)) != 0)
976 return (error);
977 ep->inode = ip->i_number;
978 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
979 EXT2_FEATURE_INCOMPAT_FILETYPE))
980 ep->file_type = DTTOFT(IFTODT(ip->i_mode));
981 else
982 ep->file_type = EXT2_FT_UNKNOWN;
983 error = BUF_WRITE(bp);
984 dp->i_flag |= IN_CHANGE | IN_UPDATE;
985 return (error);
986}
987
988/*
989 * Check if a directory is empty or not.
990 * Inode supplied must be locked.
991 *
992 * Using a struct dirtemplate here is not precisely
993 * what we want, but better than using a struct direct.
994 *
995 * NB: does not handle corrupted directories.
996 */
997int
998ext2_dirempty(ip, parentino, cred)
999 struct inode *ip;
1000 ino_t parentino;
1001 struct ucred *cred;
1002{
1003 off_t off;
1004 struct dirtemplate dbuf;
1005 struct ext2_dir_entry_2 *dp = (struct ext2_dir_entry_2 *)&dbuf;
1006 int error, count, namlen;
1007
1008#define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
1009
1010 for (off = 0; off < ip->i_size; off += dp->rec_len) {
1011 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ,
1012 off, UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK, cred,
1013 NOCRED, &count, (struct thread *)0);
1014 /*
1015 * Since we read MINDIRSIZ, residual must
1016 * be 0 unless we're at end of file.
1017 */
1018 if (error || count != 0)
1019 return (0);
1020 /* avoid infinite loops */
1021 if (dp->rec_len == 0)
1022 return (0);
1023 /* skip empty entries */
1024 if (dp->inode == 0)
1025 continue;
1026 /* accept only "." and ".." */
1027 namlen = dp->name_len;
1028 if (namlen > 2)
1029 return (0);
1030 if (dp->name[0] != '.')
1031 return (0);
1032 /*
1033 * At this point namlen must be 1 or 2.
1034 * 1 implies ".", 2 implies ".." if second
1035 * char is also "."
1036 */
1037 if (namlen == 1)
1038 continue;
1039 if (dp->name[1] == '.' && dp->inode == parentino)
1040 continue;
1041 return (0);
1042 }
1043 return (1);
1044}
1045
1046/*
1047 * Check if source directory is in the path of the target directory.
1048 * Target is supplied locked, source is unlocked.
1049 * The target is always vput before returning.
1050 */
1051int
1052ext2_checkpath(source, target, cred)
1053 struct inode *source, *target;
1054 struct ucred *cred;
1055{
1056 struct vnode *vp;
1057 int error, rootino, namlen;
1058 struct dirtemplate dirbuf;
1059
1060 vp = ITOV(target);
1061 if (target->i_number == source->i_number) {
1062 error = EEXIST;
1063 goto out;
1064 }
1065 rootino = ROOTINO;
1066 error = 0;
1067 if (target->i_number == rootino)
1068 goto out;
1069
1070 for (;;) {
1071 if (vp->v_type != VDIR) {
1072 error = ENOTDIR;
1073 break;
1074 }
1075 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1076 sizeof (struct dirtemplate), (off_t)0, UIO_SYSSPACE,
1077 IO_NODELOCKED | IO_NOMACCHECK, cred, NOCRED, (int *)0,
1078 (struct thread *)0);
1079 if (error != 0)
1080 break;
1081 namlen = dirbuf.dotdot_type; /* like ufs little-endian */
1082 if (namlen != 2 ||
1083 dirbuf.dotdot_name[0] != '.' ||
1084 dirbuf.dotdot_name[1] != '.') {
1085 error = ENOTDIR;
1086 break;
1087 }
1088 if (dirbuf.dotdot_ino == source->i_number) {
1089 error = EINVAL;
1090 break;
1091 }
1092 if (dirbuf.dotdot_ino == rootino)
1093 break;
1094 vput(vp);
1095 if ((error = VFS_VGET(vp->v_mount, dirbuf.dotdot_ino,
1096 LK_EXCLUSIVE, &vp)) != 0) {
1097 vp = NULL;
1098 break;
1099 }
1100 }
1101
1102out:
1103 if (error == ENOTDIR)
1104 printf("checkpath: .. not a directory\n");
1105 if (vp != NULL)
1106 vput(vp);
1107 return (error);
1108}
1109
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