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ceph: directory operations
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / ceph / dir.c
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2817b000
SW		 1#include "ceph_debug.h"
2
3#include <linux/spinlock.h>
4#include <linux/fs_struct.h>
5#include <linux/namei.h>
6#include <linux/sched.h>
7
8#include "super.h"
9
10/*
11 * Directory operations: readdir, lookup, create, link, unlink,
12 * rename, etc.
13 */
14
15/*
16 * Ceph MDS operations are specified in terms of a base ino and
17 * relative path. Thus, the client can specify an operation on a
18 * specific inode (e.g., a getattr due to fstat(2)), or as a path
19 * relative to, say, the root directory.
20 *
21 * Normally, we limit ourselves to strict inode ops (no path component)
22 * or dentry operations (a single path component relative to an ino). The
23 * exception to this is open_root_dentry(), which will open the mount
24 * point by name.
25 */
26
27const struct inode_operations ceph_dir_iops;
28const struct file_operations ceph_dir_fops;
29struct dentry_operations ceph_dentry_ops;
30
31/*
32 * Initialize ceph dentry state.
33 */
34int ceph_init_dentry(struct dentry *dentry)
35{
36 struct ceph_dentry_info *di;
37
38 if (dentry->d_fsdata)
39 return 0;
40
41 if (ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP)
42 dentry->d_op = &ceph_dentry_ops;
43 else if (ceph_snap(dentry->d_parent->d_inode) == CEPH_SNAPDIR)
44 dentry->d_op = &ceph_snapdir_dentry_ops;
45 else
46 dentry->d_op = &ceph_snap_dentry_ops;
47
48 di = kmem_cache_alloc(ceph_dentry_cachep, GFP_NOFS);
49 if (!di)
50 return -ENOMEM; /* oh well */
51
52 spin_lock(&dentry->d_lock);
53 if (dentry->d_fsdata) /* lost a race */
54 goto out_unlock;
55 di->dentry = dentry;
56 di->lease_session = NULL;
57 dentry->d_fsdata = di;
58 dentry->d_time = jiffies;
59 ceph_dentry_lru_add(dentry);
60out_unlock:
61 spin_unlock(&dentry->d_lock);
62 return 0;
63}
64
65
66
67/*
68 * for readdir, we encode the directory frag and offset within that
69 * frag into f_pos.
70 */
71static unsigned fpos_frag(loff_t p)
72{
73 return p >> 32;
74}
75static unsigned fpos_off(loff_t p)
76{
77 return p & 0xffffffff;
78}
79
80/*
81 * When possible, we try to satisfy a readdir by peeking at the
82 * dcache. We make this work by carefully ordering dentries on
83 * d_u.d_child when we initially get results back from the MDS, and
84 * falling back to a "normal" sync readdir if any dentries in the dir
85 * are dropped.
86 *
87 * I_COMPLETE tells indicates we have all dentries in the dir. It is
88 * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
89 * the MDS if/when the directory is modified).
90 */
91static int __dcache_readdir(struct file *filp,
92 void *dirent, filldir_t filldir)
93{
94 struct inode *inode = filp->f_dentry->d_inode;
95 struct ceph_file_info *fi = filp->private_data;
96 struct dentry *parent = filp->f_dentry;
97 struct inode *dir = parent->d_inode;
98 struct list_head *p;
99 struct dentry *dentry, *last;
100 struct ceph_dentry_info *di;
101 int err = 0;
102
103 /* claim ref on last dentry we returned */
104 last = fi->dentry;
105 fi->dentry = NULL;
106
107 dout("__dcache_readdir %p at %llu (last %p)\n", dir, filp->f_pos,
108 last);
109
110 spin_lock(&dcache_lock);
111
112 /* start at beginning? */
113 if (filp->f_pos == 2 || (last &&
114 filp->f_pos < ceph_dentry(last)->offset)) {
115 if (list_empty(&parent->d_subdirs))
116 goto out_unlock;
117 p = parent->d_subdirs.prev;
118 dout(" initial p %p/%p\n", p->prev, p->next);
119 } else {
120 p = last->d_u.d_child.prev;
121 }
122
123more:
124 dentry = list_entry(p, struct dentry, d_u.d_child);
125 di = ceph_dentry(dentry);
126 while (1) {
127 dout(" p %p/%p d_subdirs %p/%p\n", p->prev, p->next,
128 parent->d_subdirs.prev, parent->d_subdirs.next);
129 if (p == &parent->d_subdirs) {
130 fi->at_end = 1;
131 goto out_unlock;
132 }
133 if (!d_unhashed(dentry) && dentry->d_inode &&
134 filp->f_pos <= di->offset)
135 break;
136 dout(" skipping %p %.*s at %llu (%llu)%s%s\n", dentry,
137 dentry->d_name.len, dentry->d_name.name, di->offset,
138 filp->f_pos, d_unhashed(dentry) ? " unhashed" : "",
139 !dentry->d_inode ? " null" : "");
140 p = p->prev;
141 dentry = list_entry(p, struct dentry, d_u.d_child);
142 di = ceph_dentry(dentry);
143 }
144
145 atomic_inc(&dentry->d_count);
146 spin_unlock(&dcache_lock);
147 spin_unlock(&inode->i_lock);
148
149 dout(" %llu (%llu) dentry %p %.*s %p\n", di->offset, filp->f_pos,
150 dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
151 filp->f_pos = di->offset;
152 err = filldir(dirent, dentry->d_name.name,
153 dentry->d_name.len, di->offset,
154 dentry->d_inode->i_ino,
155 dentry->d_inode->i_mode >> 12);
156
157 if (last) {
158 if (err < 0) {
159 /* remember our position */
160 fi->dentry = last;
161 fi->next_offset = di->offset;
162 } else {
163 dput(last);
164 }
165 last = NULL;
166 }
167
168 spin_lock(&inode->i_lock);
169 spin_lock(&dcache_lock);
170
171 if (err < 0)
172 goto out_unlock;
173
174 last = dentry;
175
176 p = p->prev;
177 filp->f_pos++;
178
179 /* make sure a dentry wasn't dropped while we didn't have dcache_lock */
180 if ((ceph_inode(dir)->i_ceph_flags & CEPH_I_COMPLETE))
181 goto more;
182 dout(" lost I_COMPLETE on %p; falling back to mds\n", dir);
183 err = -EAGAIN;
184
185out_unlock:
186 spin_unlock(&dcache_lock);
187
188 if (last) {
189 spin_unlock(&inode->i_lock);
190 dput(last);
191 spin_lock(&inode->i_lock);
192 }
193
194 return err;
195}
196
197/*
198 * make note of the last dentry we read, so we can
199 * continue at the same lexicographical point,
200 * regardless of what dir changes take place on the
201 * server.
202 */
203static int note_last_dentry(struct ceph_file_info *fi, const char *name,
204 int len)
205{
206 kfree(fi->last_name);
207 fi->last_name = kmalloc(len+1, GFP_NOFS);
208 if (!fi->last_name)
209 return -ENOMEM;
210 memcpy(fi->last_name, name, len);
211 fi->last_name[len] = 0;
212 dout("note_last_dentry '%s'\n", fi->last_name);
213 return 0;
214}
215
216static int ceph_readdir(struct file *filp, void *dirent, filldir_t filldir)
217{
218 struct ceph_file_info *fi = filp->private_data;
219 struct inode *inode = filp->f_dentry->d_inode;
220 struct ceph_inode_info *ci = ceph_inode(inode);
221 struct ceph_client *client = ceph_inode_to_client(inode);
222 struct ceph_mds_client *mdsc = &client->mdsc;
223 unsigned frag = fpos_frag(filp->f_pos);
224 int off = fpos_off(filp->f_pos);
225 int err;
226 u32 ftype;
227 struct ceph_mds_reply_info_parsed *rinfo;
228 const int max_entries = client->mount_args.max_readdir;
229
230 dout("readdir %p filp %p frag %u off %u\n", inode, filp, frag, off);
231 if (fi->at_end)
232 return 0;
233
234 /* always start with . and .. */
235 if (filp->f_pos == 0) {
236 /* note dir version at start of readdir so we can tell
237 * if any dentries get dropped */
238 fi->dir_release_count = ci->i_release_count;
239
240 dout("readdir off 0 -> '.'\n");
241 if (filldir(dirent, ".", 1, ceph_make_fpos(0, 0),
242 inode->i_ino, inode->i_mode >> 12) < 0)
243 return 0;
244 filp->f_pos = 1;
245 off = 1;
246 }
247 if (filp->f_pos == 1) {
248 dout("readdir off 1 -> '..'\n");
249 if (filldir(dirent, "..", 2, ceph_make_fpos(0, 1),
250 filp->f_dentry->d_parent->d_inode->i_ino,
251 inode->i_mode >> 12) < 0)
252 return 0;
253 filp->f_pos = 2;
254 off = 2;
255 }
256
257 /* can we use the dcache? */
258 spin_lock(&inode->i_lock);
259 if ((filp->f_pos == 2 || fi->dentry) &&
260 !ceph_test_opt(client, NOASYNCREADDIR) &&
261 (ci->i_ceph_flags & CEPH_I_COMPLETE) &&
262 __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
263 err = __dcache_readdir(filp, dirent, filldir);
264 if (err != -EAGAIN) {
265 spin_unlock(&inode->i_lock);
266 return err;
267 }
268 }
269 spin_unlock(&inode->i_lock);
270 if (fi->dentry) {
271 err = note_last_dentry(fi, fi->dentry->d_name.name,
272 fi->dentry->d_name.len);
273 if (err)
274 return err;
275 dput(fi->dentry);
276 fi->dentry = NULL;
277 }
278
279 /* proceed with a normal readdir */
280
281more:
282 /* do we have the correct frag content buffered? */
283 if (fi->frag != frag || fi->last_readdir == NULL) {
284 struct ceph_mds_request *req;
285 int op = ceph_snap(inode) == CEPH_SNAPDIR ?
286 CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
287
288 /* discard old result, if any */
289 if (fi->last_readdir)
290 ceph_mdsc_put_request(fi->last_readdir);
291
292 /* requery frag tree, as the frag topology may have changed */
293 frag = ceph_choose_frag(ceph_inode(inode), frag, NULL, NULL);
294
295 dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
296 ceph_vinop(inode), frag, fi->last_name);
297 req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
298 if (IS_ERR(req))
299 return PTR_ERR(req);
300 req->r_inode = igrab(inode);
301 req->r_dentry = dget(filp->f_dentry);
302 /* hints to request -> mds selection code */
303 req->r_direct_mode = USE_AUTH_MDS;
304 req->r_direct_hash = ceph_frag_value(frag);
305 req->r_direct_is_hash = true;
306 req->r_path2 = kstrdup(fi->last_name, GFP_NOFS);
307 req->r_readdir_offset = fi->next_offset;
308 req->r_args.readdir.frag = cpu_to_le32(frag);
309 req->r_args.readdir.max_entries = cpu_to_le32(max_entries);
310 req->r_num_caps = max_entries;
311 err = ceph_mdsc_do_request(mdsc, NULL, req);
312 if (err < 0) {
313 ceph_mdsc_put_request(req);
314 return err;
315 }
316 dout("readdir got and parsed readdir result=%d"
317 " on frag %x, end=%d, complete=%d\n", err, frag,
318 (int)req->r_reply_info.dir_end,
319 (int)req->r_reply_info.dir_complete);
320
321 if (!req->r_did_prepopulate) {
322 dout("readdir !did_prepopulate");
323 fi->dir_release_count--; /* preclude I_COMPLETE */
324 }
325
326 /* note next offset and last dentry name */
327 fi->offset = fi->next_offset;
328 fi->last_readdir = req;
329
330 if (req->r_reply_info.dir_end) {
331 kfree(fi->last_name);
332 fi->last_name = NULL;
333 fi->next_offset = 0;
334 } else {
335 rinfo = &req->r_reply_info;
336 err = note_last_dentry(fi,
337 rinfo->dir_dname[rinfo->dir_nr-1],
338 rinfo->dir_dname_len[rinfo->dir_nr-1]);
339 if (err)
340 return err;
341 fi->next_offset += rinfo->dir_nr;
342 }
343 }
344
345 rinfo = &fi->last_readdir->r_reply_info;
346 dout("readdir frag %x num %d off %d chunkoff %d\n", frag,
347 rinfo->dir_nr, off, fi->offset);
348 while (off - fi->offset >= 0 && off - fi->offset < rinfo->dir_nr) {
349 u64 pos = ceph_make_fpos(frag, off);
350 struct ceph_mds_reply_inode *in =
351 rinfo->dir_in[off - fi->offset].in;
352 dout("readdir off %d (%d/%d) -> %lld '%.*s' %p\n",
353 off, off - fi->offset, rinfo->dir_nr, pos,
354 rinfo->dir_dname_len[off - fi->offset],
355 rinfo->dir_dname[off - fi->offset], in);
356 BUG_ON(!in);
357 ftype = le32_to_cpu(in->mode) >> 12;
358 if (filldir(dirent,
359 rinfo->dir_dname[off - fi->offset],
360 rinfo->dir_dname_len[off - fi->offset],
361 pos,
362 le64_to_cpu(in->ino),
363 ftype) < 0) {
364 dout("filldir stopping us...\n");
365 return 0;
366 }
367 off++;
368 filp->f_pos = pos + 1;
369 }
370
371 if (fi->last_name) {
372 ceph_mdsc_put_request(fi->last_readdir);
373 fi->last_readdir = NULL;
374 goto more;
375 }
376
377 /* more frags? */
378 if (!ceph_frag_is_rightmost(frag)) {
379 frag = ceph_frag_next(frag);
380 off = 0;
381 filp->f_pos = ceph_make_fpos(frag, off);
382 dout("readdir next frag is %x\n", frag);
383 goto more;
384 }
385 fi->at_end = 1;
386
387 /*
388 * if dir_release_count still matches the dir, no dentries
389 * were released during the whole readdir, and we should have
390 * the complete dir contents in our cache.
391 */
392 spin_lock(&inode->i_lock);
393 if (ci->i_release_count == fi->dir_release_count) {
394 dout(" marking %p complete\n", inode);
395 ci->i_ceph_flags |= CEPH_I_COMPLETE;
396 ci->i_max_offset = filp->f_pos;
397 }
398 spin_unlock(&inode->i_lock);
399
400 dout("readdir %p filp %p done.\n", inode, filp);
401 return 0;
402}
403
404static void reset_readdir(struct ceph_file_info *fi)
405{
406 if (fi->last_readdir) {
407 ceph_mdsc_put_request(fi->last_readdir);
408 fi->last_readdir = NULL;
409 }
410 kfree(fi->last_name);
411 fi->next_offset = 2; /* compensate for . and .. */
412 if (fi->dentry) {
413 dput(fi->dentry);
414 fi->dentry = NULL;
415 }
416 fi->at_end = 0;
417}
418
419static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int origin)
420{
421 struct ceph_file_info *fi = file->private_data;
422 struct inode *inode = file->f_mapping->host;
423 loff_t old_offset = offset;
424 loff_t retval;
425
426 mutex_lock(&inode->i_mutex);
427 switch (origin) {
428 case SEEK_END:
429 offset += inode->i_size + 2; /* FIXME */
430 break;
431 case SEEK_CUR:
432 offset += file->f_pos;
433 }
434 retval = -EINVAL;
435 if (offset >= 0 && offset <= inode->i_sb->s_maxbytes) {
436 if (offset != file->f_pos) {
437 file->f_pos = offset;
438 file->f_version = 0;
439 fi->at_end = 0;
440 }
441 retval = offset;
442
443 /*
444 * discard buffered readdir content on seekdir(0), or
445 * seek to new frag, or seek prior to current chunk.
446 */
447 if (offset == 0 ||
448 fpos_frag(offset) != fpos_frag(old_offset) ||
449 fpos_off(offset) < fi->offset) {
450 dout("dir_llseek dropping %p content\n", file);
451 reset_readdir(fi);
452 }
453
454 /* bump dir_release_count if we did a forward seek */
455 if (offset > old_offset)
456 fi->dir_release_count--;
457 }
458 mutex_unlock(&inode->i_mutex);
459 return retval;
460}
461
462/*
463 * Process result of a lookup/open request.
464 *
465 * Mainly, make sure we return the final req->r_dentry (if it already
466 * existed) in place of the original VFS-provided dentry when they
467 * differ.
468 *
469 * Gracefully handle the case where the MDS replies with -ENOENT and
470 * no trace (which it may do, at its discretion, e.g., if it doesn't
471 * care to issue a lease on the negative dentry).
472 */
473struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
474 struct dentry *dentry, int err)
475{
476 struct ceph_client *client = ceph_client(dentry->d_sb);
477 struct inode *parent = dentry->d_parent->d_inode;
478
479 /* .snap dir? */
480 if (err == -ENOENT &&
481 ceph_vino(parent).ino != CEPH_INO_ROOT && /* no .snap in root dir */
482 strcmp(dentry->d_name.name, client->mount_args.snapdir_name) == 0) {
483 struct inode *inode = ceph_get_snapdir(parent);
484 dout("ENOENT on snapdir %p '%.*s', linking to snapdir %p\n",
485 dentry, dentry->d_name.len, dentry->d_name.name, inode);
486 d_add(dentry, inode);
487 err = 0;
488 }
489
490 if (err == -ENOENT) {
491 /* no trace? */
492 err = 0;
493 if (!req->r_reply_info.head->is_dentry) {
494 dout("ENOENT and no trace, dentry %p inode %p\n",
495 dentry, dentry->d_inode);
496 if (dentry->d_inode) {
497 d_drop(dentry);
498 err = -ENOENT;
499 } else {
500 d_add(dentry, NULL);
501 }
502 }
503 }
504 if (err)
505 dentry = ERR_PTR(err);
506 else if (dentry != req->r_dentry)
507 dentry = dget(req->r_dentry); /* we got spliced */
508 else
509 dentry = NULL;
510 return dentry;
511}
512
513/*
514 * Look up a single dir entry. If there is a lookup intent, inform
515 * the MDS so that it gets our 'caps wanted' value in a single op.
516 */
517static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
518 struct nameidata *nd)
519{
520 struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
521 struct ceph_mds_client *mdsc = &client->mdsc;
522 struct ceph_mds_request *req;
523 int op;
524 int err;
525
526 dout("lookup %p dentry %p '%.*s'\n",
527 dir, dentry, dentry->d_name.len, dentry->d_name.name);
528
529 if (dentry->d_name.len > NAME_MAX)
530 return ERR_PTR(-ENAMETOOLONG);
531
532 err = ceph_init_dentry(dentry);
533 if (err < 0)
534 return ERR_PTR(err);
535
536 /* open (but not create!) intent? */
537 if (nd &&
538 (nd->flags & LOOKUP_OPEN) &&
539 (nd->flags & LOOKUP_CONTINUE) == 0 && /* only open last component */
540 !(nd->intent.open.flags & O_CREAT)) {
541 int mode = nd->intent.open.create_mode & ~current->fs->umask;
542 return ceph_lookup_open(dir, dentry, nd, mode, 1);
543 }
544
545 /* can we conclude ENOENT locally? */
546 if (dentry->d_inode == NULL) {
547 struct ceph_inode_info *ci = ceph_inode(dir);
548 struct ceph_dentry_info *di = ceph_dentry(dentry);
549
550 spin_lock(&dir->i_lock);
551 dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
552 if (strncmp(dentry->d_name.name,
553 client->mount_args.snapdir_name,
554 dentry->d_name.len) &&
555 (ci->i_ceph_flags & CEPH_I_COMPLETE) &&
556 (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
557 di->offset = ci->i_max_offset++;
558 spin_unlock(&dir->i_lock);
559 dout(" dir %p complete, -ENOENT\n", dir);
560 d_add(dentry, NULL);
561 di->lease_shared_gen = ci->i_shared_gen;
562 return NULL;
563 }
564 spin_unlock(&dir->i_lock);
565 }
566
567 op = ceph_snap(dir) == CEPH_SNAPDIR ?
568 CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
569 req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
570 if (IS_ERR(req))
571 return ERR_PTR(PTR_ERR(req));
572 req->r_dentry = dget(dentry);
573 req->r_num_caps = 2;
574 /* we only need inode linkage */
575 req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
576 req->r_locked_dir = dir;
577 err = ceph_mdsc_do_request(mdsc, NULL, req);
578 dentry = ceph_finish_lookup(req, dentry, err);
579 ceph_mdsc_put_request(req); /* will dput(dentry) */
580 dout("lookup result=%p\n", dentry);
581 return dentry;
582}
583
584/*
585 * If we do a create but get no trace back from the MDS, follow up with
586 * a lookup (the VFS expects us to link up the provided dentry).
587 */
588int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
589{
590 struct dentry *result = ceph_lookup(dir, dentry, NULL);
591
592 if (result && !IS_ERR(result)) {
593 /*
594 * We created the item, then did a lookup, and found
595 * it was already linked to another inode we already
596 * had in our cache (and thus got spliced). Link our
597 * dentry to that inode, but don't hash it, just in
598 * case the VFS wants to dereference it.
599 */
600 BUG_ON(!result->d_inode);
601 d_instantiate(dentry, result->d_inode);
602 return 0;
603 }
604 return PTR_ERR(result);
605}
606
607static int ceph_mknod(struct inode *dir, struct dentry *dentry,
608 int mode, dev_t rdev)
609{
610 struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
611 struct ceph_mds_client *mdsc = &client->mdsc;
612 struct ceph_mds_request *req;
613 int err;
614
615 if (ceph_snap(dir) != CEPH_NOSNAP)
616 return -EROFS;
617
618 dout("mknod in dir %p dentry %p mode 0%o rdev %d\n",
619 dir, dentry, mode, rdev);
620 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
621 if (IS_ERR(req)) {
622 d_drop(dentry);
623 return PTR_ERR(req);
624 }
625 req->r_dentry = dget(dentry);
626 req->r_num_caps = 2;
627 req->r_locked_dir = dir;
628 req->r_args.mknod.mode = cpu_to_le32(mode);
629 req->r_args.mknod.rdev = cpu_to_le32(rdev);
630 req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
631 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
632 err = ceph_mdsc_do_request(mdsc, dir, req);
633 if (!err && !req->r_reply_info.head->is_dentry)
634 err = ceph_handle_notrace_create(dir, dentry);
635 ceph_mdsc_put_request(req);
636 if (err)
637 d_drop(dentry);
638 return err;
639}
640
641static int ceph_create(struct inode *dir, struct dentry *dentry, int mode,
642 struct nameidata *nd)
643{
644 dout("create in dir %p dentry %p name '%.*s'\n",
645 dir, dentry, dentry->d_name.len, dentry->d_name.name);
646
647 if (ceph_snap(dir) != CEPH_NOSNAP)
648 return -EROFS;
649
650 if (nd) {
651 BUG_ON((nd->flags & LOOKUP_OPEN) == 0);
652 dentry = ceph_lookup_open(dir, dentry, nd, mode, 0);
653 /* hrm, what should i do here if we get aliased? */
654 if (IS_ERR(dentry))
655 return PTR_ERR(dentry);
656 return 0;
657 }
658
659 /* fall back to mknod */
660 return ceph_mknod(dir, dentry, (mode & ~S_IFMT) | S_IFREG, 0);
661}
662
663static int ceph_symlink(struct inode *dir, struct dentry *dentry,
664 const char *dest)
665{
666 struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
667 struct ceph_mds_client *mdsc = &client->mdsc;
668 struct ceph_mds_request *req;
669 int err;
670
671 if (ceph_snap(dir) != CEPH_NOSNAP)
672 return -EROFS;
673
674 dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
675 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
676 if (IS_ERR(req)) {
677 d_drop(dentry);
678 return PTR_ERR(req);
679 }
680 req->r_dentry = dget(dentry);
681 req->r_num_caps = 2;
682 req->r_path2 = kstrdup(dest, GFP_NOFS);
683 req->r_locked_dir = dir;
684 req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
685 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
686 err = ceph_mdsc_do_request(mdsc, dir, req);
687 if (!err && !req->r_reply_info.head->is_dentry)
688 err = ceph_handle_notrace_create(dir, dentry);
689 ceph_mdsc_put_request(req);
690 if (err)
691 d_drop(dentry);
692 return err;
693}
694
695static int ceph_mkdir(struct inode *dir, struct dentry *dentry, int mode)
696{
697 struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
698 struct ceph_mds_client *mdsc = &client->mdsc;
699 struct ceph_mds_request *req;
700 int err = -EROFS;
701 int op;
702
703 if (ceph_snap(dir) == CEPH_SNAPDIR) {
704 /* mkdir .snap/foo is a MKSNAP */
705 op = CEPH_MDS_OP_MKSNAP;
706 dout("mksnap dir %p snap '%.*s' dn %p\n", dir,
707 dentry->d_name.len, dentry->d_name.name, dentry);
708 } else if (ceph_snap(dir) == CEPH_NOSNAP) {
709 dout("mkdir dir %p dn %p mode 0%o\n", dir, dentry, mode);
710 op = CEPH_MDS_OP_MKDIR;
711 } else {
712 goto out;
713 }
714 req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
715 if (IS_ERR(req)) {
716 err = PTR_ERR(req);
717 goto out;
718 }
719
720 req->r_dentry = dget(dentry);
721 req->r_num_caps = 2;
722 req->r_locked_dir = dir;
723 req->r_args.mkdir.mode = cpu_to_le32(mode);
724 req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
725 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
726 err = ceph_mdsc_do_request(mdsc, dir, req);
727 if (!err && !req->r_reply_info.head->is_dentry)
728 err = ceph_handle_notrace_create(dir, dentry);
729 ceph_mdsc_put_request(req);
730out:
731 if (err < 0)
732 d_drop(dentry);
733 return err;
734}
735
736static int ceph_link(struct dentry *old_dentry, struct inode *dir,
737 struct dentry *dentry)
738{
739 struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
740 struct ceph_mds_client *mdsc = &client->mdsc;
741 struct ceph_mds_request *req;
742 int err;
743
744 if (ceph_snap(dir) != CEPH_NOSNAP)
745 return -EROFS;
746
747 dout("link in dir %p old_dentry %p dentry %p\n", dir,
748 old_dentry, dentry);
749 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
750 if (IS_ERR(req)) {
751 d_drop(dentry);
752 return PTR_ERR(req);
753 }
754 req->r_dentry = dget(dentry);
755 req->r_num_caps = 2;
756 req->r_old_dentry = dget(old_dentry); /* or inode? hrm. */
757 req->r_locked_dir = dir;
758 req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
759 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
760 err = ceph_mdsc_do_request(mdsc, dir, req);
761 if (err)
762 d_drop(dentry);
763 else if (!req->r_reply_info.head->is_dentry)
764 d_instantiate(dentry, igrab(old_dentry->d_inode));
765 ceph_mdsc_put_request(req);
766 return err;
767}
768
769/*
770 * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps. If it
771 * looks like the link count will hit 0, drop any other caps (other
772 * than PIN) we don't specifically want (due to the file still being
773 * open).
774 */
775static int drop_caps_for_unlink(struct inode *inode)
776{
777 struct ceph_inode_info *ci = ceph_inode(inode);
778 int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
779
780 spin_lock(&inode->i_lock);
781 if (inode->i_nlink == 1) {
782 drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
783 ci->i_ceph_flags |= CEPH_I_NODELAY;
784 }
785 spin_unlock(&inode->i_lock);
786 return drop;
787}
788
789/*
790 * rmdir and unlink are differ only by the metadata op code
791 */
792static int ceph_unlink(struct inode *dir, struct dentry *dentry)
793{
794 struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
795 struct ceph_mds_client *mdsc = &client->mdsc;
796 struct inode *inode = dentry->d_inode;
797 struct ceph_mds_request *req;
798 int err = -EROFS;
799 int op;
800
801 if (ceph_snap(dir) == CEPH_SNAPDIR) {
802 /* rmdir .snap/foo is RMSNAP */
803 dout("rmsnap dir %p '%.*s' dn %p\n", dir, dentry->d_name.len,
804 dentry->d_name.name, dentry);
805 op = CEPH_MDS_OP_RMSNAP;
806 } else if (ceph_snap(dir) == CEPH_NOSNAP) {
807 dout("unlink/rmdir dir %p dn %p inode %p\n",
808 dir, dentry, inode);
809 op = ((dentry->d_inode->i_mode & S_IFMT) == S_IFDIR) ?
810 CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
811 } else
812 goto out;
813 req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
814 if (IS_ERR(req)) {
815 err = PTR_ERR(req);
816 goto out;
817 }
818 req->r_dentry = dget(dentry);
819 req->r_num_caps = 2;
820 req->r_locked_dir = dir;
821 req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
822 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
823 req->r_inode_drop = drop_caps_for_unlink(inode);
824 err = ceph_mdsc_do_request(mdsc, dir, req);
825 if (!err && !req->r_reply_info.head->is_dentry)
826 d_delete(dentry);
827 ceph_mdsc_put_request(req);
828out:
829 return err;
830}
831
832static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
833 struct inode *new_dir, struct dentry *new_dentry)
834{
835 struct ceph_client *client = ceph_sb_to_client(old_dir->i_sb);
836 struct ceph_mds_client *mdsc = &client->mdsc;
837 struct ceph_mds_request *req;
838 int err;
839
840 if (ceph_snap(old_dir) != ceph_snap(new_dir))
841 return -EXDEV;
842 if (ceph_snap(old_dir) != CEPH_NOSNAP ||
843 ceph_snap(new_dir) != CEPH_NOSNAP)
844 return -EROFS;
845 dout("rename dir %p dentry %p to dir %p dentry %p\n",
846 old_dir, old_dentry, new_dir, new_dentry);
847 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_RENAME, USE_AUTH_MDS);
848 if (IS_ERR(req))
849 return PTR_ERR(req);
850 req->r_dentry = dget(new_dentry);
851 req->r_num_caps = 2;
852 req->r_old_dentry = dget(old_dentry);
853 req->r_locked_dir = new_dir;
854 req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
855 req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
856 req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
857 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
858 /* release LINK_RDCACHE on source inode (mds will lock it) */
859 req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
860 if (new_dentry->d_inode)
861 req->r_inode_drop = drop_caps_for_unlink(new_dentry->d_inode);
862 err = ceph_mdsc_do_request(mdsc, old_dir, req);
863 if (!err && !req->r_reply_info.head->is_dentry) {
864 /*
865 * Normally d_move() is done by fill_trace (called by
866 * do_request, above). If there is no trace, we need
867 * to do it here.
868 */
869 d_move(old_dentry, new_dentry);
870 }
871 ceph_mdsc_put_request(req);
872 return err;
873}
874
875
876/*
877 * Check if dentry lease is valid. If not, delete the lease. Try to
878 * renew if the least is more than half up.
879 */
880static int dentry_lease_is_valid(struct dentry *dentry)
881{
882 struct ceph_dentry_info *di;
883 struct ceph_mds_session *s;
884 int valid = 0;
885 u32 gen;
886 unsigned long ttl;
887 struct ceph_mds_session *session = NULL;
888 struct inode *dir = NULL;
889 u32 seq = 0;
890
891 spin_lock(&dentry->d_lock);
892 di = ceph_dentry(dentry);
893 if (di && di->lease_session) {
894 s = di->lease_session;
895 spin_lock(&s->s_cap_lock);
896 gen = s->s_cap_gen;
897 ttl = s->s_cap_ttl;
898 spin_unlock(&s->s_cap_lock);
899
900 if (di->lease_gen == gen &&
901 time_before(jiffies, dentry->d_time) &&
902 time_before(jiffies, ttl)) {
903 valid = 1;
904 if (di->lease_renew_after &&
905 time_after(jiffies, di->lease_renew_after)) {
906 /* we should renew */
907 dir = dentry->d_parent->d_inode;
908 session = ceph_get_mds_session(s);
909 seq = di->lease_seq;
910 di->lease_renew_after = 0;
911 di->lease_renew_from = jiffies;
912 }
913 } else {
914 __ceph_mdsc_drop_dentry_lease(dentry);
915 }
916 }
917 spin_unlock(&dentry->d_lock);
918
919 if (session) {
920 ceph_mdsc_lease_send_msg(session, dir, dentry,
921 CEPH_MDS_LEASE_RENEW, seq);
922 ceph_put_mds_session(session);
923 }
924 dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
925 return valid;
926}
927
928/*
929 * Check if directory-wide content lease/cap is valid.
930 */
931static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
932{
933 struct ceph_inode_info *ci = ceph_inode(dir);
934 struct ceph_dentry_info *di = ceph_dentry(dentry);
935 int valid = 0;
936
937 spin_lock(&dir->i_lock);
938 if (ci->i_shared_gen == di->lease_shared_gen)
939 valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
940 spin_unlock(&dir->i_lock);
941 dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
942 dir, (unsigned)ci->i_shared_gen, dentry,
943 (unsigned)di->lease_shared_gen, valid);
944 return valid;
945}
946
947/*
948 * Check if cached dentry can be trusted.
949 */
950static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd)
951{
952 struct inode *dir = dentry->d_parent->d_inode;
953
954 dout("d_revalidate %p '%.*s' inode %p\n", dentry,
955 dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
956
957 /* always trust cached snapped dentries, snapdir dentry */
958 if (ceph_snap(dir) != CEPH_NOSNAP) {
959 dout("d_revalidate %p '%.*s' inode %p is SNAPPED\n", dentry,
960 dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
961 goto out_touch;
962 }
963 if (dentry->d_inode && ceph_snap(dentry->d_inode) == CEPH_SNAPDIR)
964 goto out_touch;
965
966 if (dentry_lease_is_valid(dentry) ||
967 dir_lease_is_valid(dir, dentry))
968 goto out_touch;
969
970 dout("d_revalidate %p invalid\n", dentry);
971 d_drop(dentry);
972 return 0;
973out_touch:
974 ceph_dentry_lru_touch(dentry);
975 return 1;
976}
977
978/*
979 * When a dentry is released, clear the dir I_COMPLETE if it was part
980 * of the current dir gen.
981 */
982static void ceph_dentry_release(struct dentry *dentry)
983{
984 struct ceph_dentry_info *di = ceph_dentry(dentry);
985 struct inode *parent_inode = dentry->d_parent->d_inode;
986
987 if (parent_inode) {
988 struct ceph_inode_info *ci = ceph_inode(parent_inode);
989
990 spin_lock(&parent_inode->i_lock);
991 if (ci->i_shared_gen == di->lease_shared_gen) {
992 dout(" clearing %p complete (d_release)\n",
993 parent_inode);
994 ci->i_ceph_flags &= ~CEPH_I_COMPLETE;
995 ci->i_release_count++;
996 }
997 spin_unlock(&parent_inode->i_lock);
998 }
999 if (di) {
1000 ceph_dentry_lru_del(dentry);
1001 if (di->lease_session)
1002 ceph_put_mds_session(di->lease_session);
1003 kmem_cache_free(ceph_dentry_cachep, di);
1004 dentry->d_fsdata = NULL;
1005 }
1006}
1007
1008static int ceph_snapdir_d_revalidate(struct dentry *dentry,
1009 struct nameidata *nd)
1010{
1011 /*
1012 * Eventually, we'll want to revalidate snapped metadata
1013 * too... probably...
1014 */
1015 return 1;
1016}
1017
1018
1019
1020/*
1021 * read() on a dir. This weird interface hack only works if mounted
1022 * with '-o dirstat'.
1023 */
1024static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1025 loff_t *ppos)
1026{
1027 struct ceph_file_info *cf = file->private_data;
1028 struct inode *inode = file->f_dentry->d_inode;
1029 struct ceph_inode_info *ci = ceph_inode(inode);
1030 int left;
1031
1032 if (!ceph_test_opt(ceph_client(inode->i_sb), DIRSTAT))
1033 return -EISDIR;
1034
1035 if (!cf->dir_info) {
1036 cf->dir_info = kmalloc(1024, GFP_NOFS);
1037 if (!cf->dir_info)
1038 return -ENOMEM;
1039 cf->dir_info_len =
1040 sprintf(cf->dir_info,
1041 "entries: %20lld\n"
1042 " files: %20lld\n"
1043 " subdirs: %20lld\n"
1044 "rentries: %20lld\n"
1045 " rfiles: %20lld\n"
1046 " rsubdirs: %20lld\n"
1047 "rbytes: %20lld\n"
1048 "rctime: %10ld.%09ld\n",
1049 ci->i_files + ci->i_subdirs,
1050 ci->i_files,
1051 ci->i_subdirs,
1052 ci->i_rfiles + ci->i_rsubdirs,
1053 ci->i_rfiles,
1054 ci->i_rsubdirs,
1055 ci->i_rbytes,
1056 (long)ci->i_rctime.tv_sec,
1057 (long)ci->i_rctime.tv_nsec);
1058 }
1059
1060 if (*ppos >= cf->dir_info_len)
1061 return 0;
1062 size = min_t(unsigned, size, cf->dir_info_len-*ppos);
1063 left = copy_to_user(buf, cf->dir_info + *ppos, size);
1064 if (left == size)
1065 return -EFAULT;
1066 *ppos += (size - left);
1067 return size - left;
1068}
1069
1070/*
1071 * an fsync() on a dir will wait for any uncommitted directory
1072 * operations to commit.
1073 */
1074static int ceph_dir_fsync(struct file *file, struct dentry *dentry,
1075 int datasync)
1076{
1077 struct inode *inode = dentry->d_inode;
1078 struct ceph_inode_info *ci = ceph_inode(inode);
1079 struct list_head *head = &ci->i_unsafe_dirops;
1080 struct ceph_mds_request *req;
1081 u64 last_tid;
1082 int ret = 0;
1083
1084 dout("dir_fsync %p\n", inode);
1085 spin_lock(&ci->i_unsafe_lock);
1086 if (list_empty(head))
1087 goto out;
1088
1089 req = list_entry(head->prev,
1090 struct ceph_mds_request, r_unsafe_dir_item);
1091 last_tid = req->r_tid;
1092
1093 do {
1094 ceph_mdsc_get_request(req);
1095 spin_unlock(&ci->i_unsafe_lock);
1096 dout("dir_fsync %p wait on tid %llu (until %llu)\n",
1097 inode, req->r_tid, last_tid);
1098 if (req->r_timeout) {
1099 ret = wait_for_completion_timeout(
1100 &req->r_safe_completion, req->r_timeout);
1101 if (ret > 0)
1102 ret = 0;
1103 else if (ret == 0)
1104 ret = -EIO; /* timed out */
1105 } else {
1106 wait_for_completion(&req->r_safe_completion);
1107 }
1108 spin_lock(&ci->i_unsafe_lock);
1109 ceph_mdsc_put_request(req);
1110
1111 if (ret || list_empty(head))
1112 break;
1113 req = list_entry(head->next,
1114 struct ceph_mds_request, r_unsafe_dir_item);
1115 } while (req->r_tid < last_tid);
1116out:
1117 spin_unlock(&ci->i_unsafe_lock);
1118 return ret;
1119}
1120
1121/*
1122 * We maintain a private dentry LRU.
1123 *
1124 * FIXME: this needs to be changed to a per-mds lru to be useful.
1125 */
1126void ceph_dentry_lru_add(struct dentry *dn)
1127{
1128 struct ceph_dentry_info *di = ceph_dentry(dn);
1129 struct ceph_mds_client *mdsc;
1130 dout("dentry_lru_add %p %p\t%.*s\n",
1131 di, dn, dn->d_name.len, dn->d_name.name);
1132
1133 if (di) {
1134 mdsc = &ceph_client(dn->d_sb)->mdsc;
1135 spin_lock(&mdsc->dentry_lru_lock);
1136 list_add_tail(&di->lru, &mdsc->dentry_lru);
1137 mdsc->num_dentry++;
1138 spin_unlock(&mdsc->dentry_lru_lock);
1139 }
1140}
1141
1142void ceph_dentry_lru_touch(struct dentry *dn)
1143{
1144 struct ceph_dentry_info *di = ceph_dentry(dn);
1145 struct ceph_mds_client *mdsc;
1146 dout("dentry_lru_touch %p %p\t%.*s\n",
1147 di, dn, dn->d_name.len, dn->d_name.name);
1148
1149 if (di) {
1150 mdsc = &ceph_client(dn->d_sb)->mdsc;
1151 spin_lock(&mdsc->dentry_lru_lock);
1152 list_move_tail(&di->lru, &mdsc->dentry_lru);
1153 spin_unlock(&mdsc->dentry_lru_lock);
1154 }
1155}
1156
1157void ceph_dentry_lru_del(struct dentry *dn)
1158{
1159 struct ceph_dentry_info *di = ceph_dentry(dn);
1160 struct ceph_mds_client *mdsc;
1161
1162 dout("dentry_lru_del %p %p\t%.*s\n",
1163 di, dn, dn->d_name.len, dn->d_name.name);
1164 if (di) {
1165 mdsc = &ceph_client(dn->d_sb)->mdsc;
1166 spin_lock(&mdsc->dentry_lru_lock);
1167 list_del_init(&di->lru);
1168 mdsc->num_dentry--;
1169 spin_unlock(&mdsc->dentry_lru_lock);
1170 }
1171}
1172
1173const struct file_operations ceph_dir_fops = {
1174 .read = ceph_read_dir,
1175 .readdir = ceph_readdir,
1176 .llseek = ceph_dir_llseek,
1177 .open = ceph_open,
1178 .release = ceph_release,
1179 .unlocked_ioctl = ceph_ioctl,
1180 .fsync = ceph_dir_fsync,
1181};
1182
1183const struct inode_operations ceph_dir_iops = {
1184 .lookup = ceph_lookup,
1185 .permission = ceph_permission,
1186 .getattr = ceph_getattr,
1187 .setattr = ceph_setattr,
1188 .setxattr = ceph_setxattr,
1189 .getxattr = ceph_getxattr,
1190 .listxattr = ceph_listxattr,
1191 .removexattr = ceph_removexattr,
1192 .mknod = ceph_mknod,
1193 .symlink = ceph_symlink,
1194 .mkdir = ceph_mkdir,
1195 .link = ceph_link,
1196 .unlink = ceph_unlink,
1197 .rmdir = ceph_unlink,
1198 .rename = ceph_rename,
1199 .create = ceph_create,
1200};
1201
1202struct dentry_operations ceph_dentry_ops = {
1203 .d_revalidate = ceph_d_revalidate,
1204 .d_release = ceph_dentry_release,
1205};
1206
1207struct dentry_operations ceph_snapdir_dentry_ops = {
1208 .d_revalidate = ceph_snapdir_d_revalidate,
1209};
1210
1211struct dentry_operations ceph_snap_dentry_ops = {
1212};
kernel source for telekom puls (alcatel/mediatek)