xref: /openbmc/linux/fs/ceph/file.c (revision eb3fcf00)
1 #include <linux/ceph/ceph_debug.h>
2 
3 #include <linux/module.h>
4 #include <linux/sched.h>
5 #include <linux/slab.h>
6 #include <linux/file.h>
7 #include <linux/mount.h>
8 #include <linux/namei.h>
9 #include <linux/writeback.h>
10 #include <linux/falloc.h>
11 
12 #include "super.h"
13 #include "mds_client.h"
14 #include "cache.h"
15 
16 /*
17  * Ceph file operations
18  *
19  * Implement basic open/close functionality, and implement
20  * read/write.
21  *
22  * We implement three modes of file I/O:
23  *  - buffered uses the generic_file_aio_{read,write} helpers
24  *
25  *  - synchronous is used when there is multi-client read/write
26  *    sharing, avoids the page cache, and synchronously waits for an
27  *    ack from the OSD.
28  *
29  *  - direct io takes the variant of the sync path that references
30  *    user pages directly.
31  *
32  * fsync() flushes and waits on dirty pages, but just queues metadata
33  * for writeback: since the MDS can recover size and mtime there is no
34  * need to wait for MDS acknowledgement.
35  */
36 
37 
38 /*
39  * Prepare an open request.  Preallocate ceph_cap to avoid an
40  * inopportune ENOMEM later.
41  */
42 static struct ceph_mds_request *
43 prepare_open_request(struct super_block *sb, int flags, int create_mode)
44 {
45 	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
46 	struct ceph_mds_client *mdsc = fsc->mdsc;
47 	struct ceph_mds_request *req;
48 	int want_auth = USE_ANY_MDS;
49 	int op = (flags & O_CREAT) ? CEPH_MDS_OP_CREATE : CEPH_MDS_OP_OPEN;
50 
51 	if (flags & (O_WRONLY|O_RDWR|O_CREAT|O_TRUNC))
52 		want_auth = USE_AUTH_MDS;
53 
54 	req = ceph_mdsc_create_request(mdsc, op, want_auth);
55 	if (IS_ERR(req))
56 		goto out;
57 	req->r_fmode = ceph_flags_to_mode(flags);
58 	req->r_args.open.flags = cpu_to_le32(flags);
59 	req->r_args.open.mode = cpu_to_le32(create_mode);
60 out:
61 	return req;
62 }
63 
64 /*
65  * initialize private struct file data.
66  * if we fail, clean up by dropping fmode reference on the ceph_inode
67  */
68 static int ceph_init_file(struct inode *inode, struct file *file, int fmode)
69 {
70 	struct ceph_file_info *cf;
71 	int ret = 0;
72 	struct ceph_inode_info *ci = ceph_inode(inode);
73 	struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
74 	struct ceph_mds_client *mdsc = fsc->mdsc;
75 
76 	switch (inode->i_mode & S_IFMT) {
77 	case S_IFREG:
78 		/* First file open request creates the cookie, we want to keep
79 		 * this cookie around for the filetime of the inode as not to
80 		 * have to worry about fscache register / revoke / operation
81 		 * races.
82 		 *
83 		 * Also, if we know the operation is going to invalidate data
84 		 * (non readonly) just nuke the cache right away.
85 		 */
86 		ceph_fscache_register_inode_cookie(mdsc->fsc, ci);
87 		if ((fmode & CEPH_FILE_MODE_WR))
88 			ceph_fscache_invalidate(inode);
89 	case S_IFDIR:
90 		dout("init_file %p %p 0%o (regular)\n", inode, file,
91 		     inode->i_mode);
92 		cf = kmem_cache_alloc(ceph_file_cachep, GFP_KERNEL | __GFP_ZERO);
93 		if (cf == NULL) {
94 			ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
95 			return -ENOMEM;
96 		}
97 		cf->fmode = fmode;
98 		cf->next_offset = 2;
99 		cf->readdir_cache_idx = -1;
100 		file->private_data = cf;
101 		BUG_ON(inode->i_fop->release != ceph_release);
102 		break;
103 
104 	case S_IFLNK:
105 		dout("init_file %p %p 0%o (symlink)\n", inode, file,
106 		     inode->i_mode);
107 		ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
108 		break;
109 
110 	default:
111 		dout("init_file %p %p 0%o (special)\n", inode, file,
112 		     inode->i_mode);
113 		/*
114 		 * we need to drop the open ref now, since we don't
115 		 * have .release set to ceph_release.
116 		 */
117 		ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
118 		BUG_ON(inode->i_fop->release == ceph_release);
119 
120 		/* call the proper open fop */
121 		ret = inode->i_fop->open(inode, file);
122 	}
123 	return ret;
124 }
125 
126 /*
127  * If we already have the requisite capabilities, we can satisfy
128  * the open request locally (no need to request new caps from the
129  * MDS).  We do, however, need to inform the MDS (asynchronously)
130  * if our wanted caps set expands.
131  */
132 int ceph_open(struct inode *inode, struct file *file)
133 {
134 	struct ceph_inode_info *ci = ceph_inode(inode);
135 	struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
136 	struct ceph_mds_client *mdsc = fsc->mdsc;
137 	struct ceph_mds_request *req;
138 	struct ceph_file_info *cf = file->private_data;
139 	int err;
140 	int flags, fmode, wanted;
141 
142 	if (cf) {
143 		dout("open file %p is already opened\n", file);
144 		return 0;
145 	}
146 
147 	/* filter out O_CREAT|O_EXCL; vfs did that already.  yuck. */
148 	flags = file->f_flags & ~(O_CREAT|O_EXCL);
149 	if (S_ISDIR(inode->i_mode))
150 		flags = O_DIRECTORY;  /* mds likes to know */
151 
152 	dout("open inode %p ino %llx.%llx file %p flags %d (%d)\n", inode,
153 	     ceph_vinop(inode), file, flags, file->f_flags);
154 	fmode = ceph_flags_to_mode(flags);
155 	wanted = ceph_caps_for_mode(fmode);
156 
157 	/* snapped files are read-only */
158 	if (ceph_snap(inode) != CEPH_NOSNAP && (file->f_mode & FMODE_WRITE))
159 		return -EROFS;
160 
161 	/* trivially open snapdir */
162 	if (ceph_snap(inode) == CEPH_SNAPDIR) {
163 		spin_lock(&ci->i_ceph_lock);
164 		__ceph_get_fmode(ci, fmode);
165 		spin_unlock(&ci->i_ceph_lock);
166 		return ceph_init_file(inode, file, fmode);
167 	}
168 
169 	/*
170 	 * No need to block if we have caps on the auth MDS (for
171 	 * write) or any MDS (for read).  Update wanted set
172 	 * asynchronously.
173 	 */
174 	spin_lock(&ci->i_ceph_lock);
175 	if (__ceph_is_any_real_caps(ci) &&
176 	    (((fmode & CEPH_FILE_MODE_WR) == 0) || ci->i_auth_cap)) {
177 		int mds_wanted = __ceph_caps_mds_wanted(ci);
178 		int issued = __ceph_caps_issued(ci, NULL);
179 
180 		dout("open %p fmode %d want %s issued %s using existing\n",
181 		     inode, fmode, ceph_cap_string(wanted),
182 		     ceph_cap_string(issued));
183 		__ceph_get_fmode(ci, fmode);
184 		spin_unlock(&ci->i_ceph_lock);
185 
186 		/* adjust wanted? */
187 		if ((issued & wanted) != wanted &&
188 		    (mds_wanted & wanted) != wanted &&
189 		    ceph_snap(inode) != CEPH_SNAPDIR)
190 			ceph_check_caps(ci, 0, NULL);
191 
192 		return ceph_init_file(inode, file, fmode);
193 	} else if (ceph_snap(inode) != CEPH_NOSNAP &&
194 		   (ci->i_snap_caps & wanted) == wanted) {
195 		__ceph_get_fmode(ci, fmode);
196 		spin_unlock(&ci->i_ceph_lock);
197 		return ceph_init_file(inode, file, fmode);
198 	}
199 
200 	spin_unlock(&ci->i_ceph_lock);
201 
202 	dout("open fmode %d wants %s\n", fmode, ceph_cap_string(wanted));
203 	req = prepare_open_request(inode->i_sb, flags, 0);
204 	if (IS_ERR(req)) {
205 		err = PTR_ERR(req);
206 		goto out;
207 	}
208 	req->r_inode = inode;
209 	ihold(inode);
210 
211 	req->r_num_caps = 1;
212 	err = ceph_mdsc_do_request(mdsc, NULL, req);
213 	if (!err)
214 		err = ceph_init_file(inode, file, req->r_fmode);
215 	ceph_mdsc_put_request(req);
216 	dout("open result=%d on %llx.%llx\n", err, ceph_vinop(inode));
217 out:
218 	return err;
219 }
220 
221 
222 /*
223  * Do a lookup + open with a single request.  If we get a non-existent
224  * file or symlink, return 1 so the VFS can retry.
225  */
226 int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
227 		     struct file *file, unsigned flags, umode_t mode,
228 		     int *opened)
229 {
230 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
231 	struct ceph_mds_client *mdsc = fsc->mdsc;
232 	struct ceph_mds_request *req;
233 	struct dentry *dn;
234 	struct ceph_acls_info acls = {};
235 	int err;
236 
237 	dout("atomic_open %p dentry %p '%pd' %s flags %d mode 0%o\n",
238 	     dir, dentry, dentry,
239 	     d_unhashed(dentry) ? "unhashed" : "hashed", flags, mode);
240 
241 	if (dentry->d_name.len > NAME_MAX)
242 		return -ENAMETOOLONG;
243 
244 	err = ceph_init_dentry(dentry);
245 	if (err < 0)
246 		return err;
247 
248 	if (flags & O_CREAT) {
249 		err = ceph_pre_init_acls(dir, &mode, &acls);
250 		if (err < 0)
251 			return err;
252 	}
253 
254 	/* do the open */
255 	req = prepare_open_request(dir->i_sb, flags, mode);
256 	if (IS_ERR(req)) {
257 		err = PTR_ERR(req);
258 		goto out_acl;
259 	}
260 	req->r_dentry = dget(dentry);
261 	req->r_num_caps = 2;
262 	if (flags & O_CREAT) {
263 		req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
264 		req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
265 		if (acls.pagelist) {
266 			req->r_pagelist = acls.pagelist;
267 			acls.pagelist = NULL;
268 		}
269 	}
270 	req->r_locked_dir = dir;           /* caller holds dir->i_mutex */
271 	err = ceph_mdsc_do_request(mdsc,
272 				   (flags & (O_CREAT|O_TRUNC)) ? dir : NULL,
273 				   req);
274 	err = ceph_handle_snapdir(req, dentry, err);
275 	if (err)
276 		goto out_req;
277 
278 	if ((flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
279 		err = ceph_handle_notrace_create(dir, dentry);
280 
281 	if (d_unhashed(dentry)) {
282 		dn = ceph_finish_lookup(req, dentry, err);
283 		if (IS_ERR(dn))
284 			err = PTR_ERR(dn);
285 	} else {
286 		/* we were given a hashed negative dentry */
287 		dn = NULL;
288 	}
289 	if (err)
290 		goto out_req;
291 	if (dn || d_really_is_negative(dentry) || d_is_symlink(dentry)) {
292 		/* make vfs retry on splice, ENOENT, or symlink */
293 		dout("atomic_open finish_no_open on dn %p\n", dn);
294 		err = finish_no_open(file, dn);
295 	} else {
296 		dout("atomic_open finish_open on dn %p\n", dn);
297 		if (req->r_op == CEPH_MDS_OP_CREATE && req->r_reply_info.has_create_ino) {
298 			ceph_init_inode_acls(d_inode(dentry), &acls);
299 			*opened |= FILE_CREATED;
300 		}
301 		err = finish_open(file, dentry, ceph_open, opened);
302 	}
303 out_req:
304 	if (!req->r_err && req->r_target_inode)
305 		ceph_put_fmode(ceph_inode(req->r_target_inode), req->r_fmode);
306 	ceph_mdsc_put_request(req);
307 out_acl:
308 	ceph_release_acls_info(&acls);
309 	dout("atomic_open result=%d\n", err);
310 	return err;
311 }
312 
313 int ceph_release(struct inode *inode, struct file *file)
314 {
315 	struct ceph_inode_info *ci = ceph_inode(inode);
316 	struct ceph_file_info *cf = file->private_data;
317 
318 	dout("release inode %p file %p\n", inode, file);
319 	ceph_put_fmode(ci, cf->fmode);
320 	if (cf->last_readdir)
321 		ceph_mdsc_put_request(cf->last_readdir);
322 	kfree(cf->last_name);
323 	kfree(cf->dir_info);
324 	kmem_cache_free(ceph_file_cachep, cf);
325 
326 	/* wake up anyone waiting for caps on this inode */
327 	wake_up_all(&ci->i_cap_wq);
328 	return 0;
329 }
330 
331 enum {
332 	CHECK_EOF = 1,
333 	READ_INLINE = 2,
334 };
335 
336 /*
337  * Read a range of bytes striped over one or more objects.  Iterate over
338  * objects we stripe over.  (That's not atomic, but good enough for now.)
339  *
340  * If we get a short result from the OSD, check against i_size; we need to
341  * only return a short read to the caller if we hit EOF.
342  */
343 static int striped_read(struct inode *inode,
344 			u64 off, u64 len,
345 			struct page **pages, int num_pages,
346 			int *checkeof, bool o_direct,
347 			unsigned long buf_align)
348 {
349 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
350 	struct ceph_inode_info *ci = ceph_inode(inode);
351 	u64 pos, this_len, left;
352 	int io_align, page_align;
353 	int pages_left;
354 	int read;
355 	struct page **page_pos;
356 	int ret;
357 	bool hit_stripe, was_short;
358 
359 	/*
360 	 * we may need to do multiple reads.  not atomic, unfortunately.
361 	 */
362 	pos = off;
363 	left = len;
364 	page_pos = pages;
365 	pages_left = num_pages;
366 	read = 0;
367 	io_align = off & ~PAGE_MASK;
368 
369 more:
370 	if (o_direct)
371 		page_align = (pos - io_align + buf_align) & ~PAGE_MASK;
372 	else
373 		page_align = pos & ~PAGE_MASK;
374 	this_len = left;
375 	ret = ceph_osdc_readpages(&fsc->client->osdc, ceph_vino(inode),
376 				  &ci->i_layout, pos, &this_len,
377 				  ci->i_truncate_seq,
378 				  ci->i_truncate_size,
379 				  page_pos, pages_left, page_align);
380 	if (ret == -ENOENT)
381 		ret = 0;
382 	hit_stripe = this_len < left;
383 	was_short = ret >= 0 && ret < this_len;
384 	dout("striped_read %llu~%llu (read %u) got %d%s%s\n", pos, left, read,
385 	     ret, hit_stripe ? " HITSTRIPE" : "", was_short ? " SHORT" : "");
386 
387 	if (ret >= 0) {
388 		int didpages;
389 		if (was_short && (pos + ret < inode->i_size)) {
390 			int zlen = min(this_len - ret,
391 				       inode->i_size - pos - ret);
392 			int zoff = (o_direct ? buf_align : io_align) +
393 				    read + ret;
394 			dout(" zero gap %llu to %llu\n",
395 				pos + ret, pos + ret + zlen);
396 			ceph_zero_page_vector_range(zoff, zlen, pages);
397 			ret += zlen;
398 		}
399 
400 		didpages = (page_align + ret) >> PAGE_CACHE_SHIFT;
401 		pos += ret;
402 		read = pos - off;
403 		left -= ret;
404 		page_pos += didpages;
405 		pages_left -= didpages;
406 
407 		/* hit stripe and need continue*/
408 		if (left && hit_stripe && pos < inode->i_size)
409 			goto more;
410 	}
411 
412 	if (read > 0) {
413 		ret = read;
414 		/* did we bounce off eof? */
415 		if (pos + left > inode->i_size)
416 			*checkeof = CHECK_EOF;
417 	}
418 
419 	dout("striped_read returns %d\n", ret);
420 	return ret;
421 }
422 
423 /*
424  * Completely synchronous read and write methods.  Direct from __user
425  * buffer to osd, or directly to user pages (if O_DIRECT).
426  *
427  * If the read spans object boundary, just do multiple reads.
428  */
429 static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *i,
430 				int *checkeof)
431 {
432 	struct file *file = iocb->ki_filp;
433 	struct inode *inode = file_inode(file);
434 	struct page **pages;
435 	u64 off = iocb->ki_pos;
436 	int num_pages, ret;
437 	size_t len = iov_iter_count(i);
438 
439 	dout("sync_read on file %p %llu~%u %s\n", file, off,
440 	     (unsigned)len,
441 	     (file->f_flags & O_DIRECT) ? "O_DIRECT" : "");
442 
443 	if (!len)
444 		return 0;
445 	/*
446 	 * flush any page cache pages in this range.  this
447 	 * will make concurrent normal and sync io slow,
448 	 * but it will at least behave sensibly when they are
449 	 * in sequence.
450 	 */
451 	ret = filemap_write_and_wait_range(inode->i_mapping, off,
452 						off + len);
453 	if (ret < 0)
454 		return ret;
455 
456 	if (iocb->ki_flags & IOCB_DIRECT) {
457 		while (iov_iter_count(i)) {
458 			size_t start;
459 			ssize_t n;
460 
461 			n = iov_iter_get_pages_alloc(i, &pages, INT_MAX, &start);
462 			if (n < 0)
463 				return n;
464 
465 			num_pages = (n + start + PAGE_SIZE - 1) / PAGE_SIZE;
466 
467 			ret = striped_read(inode, off, n,
468 					   pages, num_pages, checkeof,
469 					   1, start);
470 
471 			ceph_put_page_vector(pages, num_pages, true);
472 
473 			if (ret <= 0)
474 				break;
475 			off += ret;
476 			iov_iter_advance(i, ret);
477 			if (ret < n)
478 				break;
479 		}
480 	} else {
481 		num_pages = calc_pages_for(off, len);
482 		pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
483 		if (IS_ERR(pages))
484 			return PTR_ERR(pages);
485 		ret = striped_read(inode, off, len, pages,
486 					num_pages, checkeof, 0, 0);
487 		if (ret > 0) {
488 			int l, k = 0;
489 			size_t left = ret;
490 
491 			while (left) {
492 				size_t page_off = off & ~PAGE_MASK;
493 				size_t copy = min_t(size_t,
494 						    PAGE_SIZE - page_off, left);
495 				l = copy_page_to_iter(pages[k++], page_off,
496 						      copy, i);
497 				off += l;
498 				left -= l;
499 				if (l < copy)
500 					break;
501 			}
502 		}
503 		ceph_release_page_vector(pages, num_pages);
504 	}
505 
506 	if (off > iocb->ki_pos) {
507 		ret = off - iocb->ki_pos;
508 		iocb->ki_pos = off;
509 	}
510 
511 	dout("sync_read result %d\n", ret);
512 	return ret;
513 }
514 
515 /*
516  * Write commit request unsafe callback, called to tell us when a
517  * request is unsafe (that is, in flight--has been handed to the
518  * messenger to send to its target osd).  It is called again when
519  * we've received a response message indicating the request is
520  * "safe" (its CEPH_OSD_FLAG_ONDISK flag is set), or when a request
521  * is completed early (and unsuccessfully) due to a timeout or
522  * interrupt.
523  *
524  * This is used if we requested both an ACK and ONDISK commit reply
525  * from the OSD.
526  */
527 static void ceph_sync_write_unsafe(struct ceph_osd_request *req, bool unsafe)
528 {
529 	struct ceph_inode_info *ci = ceph_inode(req->r_inode);
530 
531 	dout("%s %p tid %llu %ssafe\n", __func__, req, req->r_tid,
532 		unsafe ? "un" : "");
533 	if (unsafe) {
534 		ceph_get_cap_refs(ci, CEPH_CAP_FILE_WR);
535 		spin_lock(&ci->i_unsafe_lock);
536 		list_add_tail(&req->r_unsafe_item,
537 			      &ci->i_unsafe_writes);
538 		spin_unlock(&ci->i_unsafe_lock);
539 	} else {
540 		spin_lock(&ci->i_unsafe_lock);
541 		list_del_init(&req->r_unsafe_item);
542 		spin_unlock(&ci->i_unsafe_lock);
543 		ceph_put_cap_refs(ci, CEPH_CAP_FILE_WR);
544 	}
545 }
546 
547 
548 /*
549  * Synchronous write, straight from __user pointer or user pages.
550  *
551  * If write spans object boundary, just do multiple writes.  (For a
552  * correct atomic write, we should e.g. take write locks on all
553  * objects, rollback on failure, etc.)
554  */
555 static ssize_t
556 ceph_sync_direct_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos,
557 		       struct ceph_snap_context *snapc)
558 {
559 	struct file *file = iocb->ki_filp;
560 	struct inode *inode = file_inode(file);
561 	struct ceph_inode_info *ci = ceph_inode(inode);
562 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
563 	struct ceph_vino vino;
564 	struct ceph_osd_request *req;
565 	struct page **pages;
566 	int num_pages;
567 	int written = 0;
568 	int flags;
569 	int check_caps = 0;
570 	int ret;
571 	struct timespec mtime = CURRENT_TIME;
572 	size_t count = iov_iter_count(from);
573 
574 	if (ceph_snap(file_inode(file)) != CEPH_NOSNAP)
575 		return -EROFS;
576 
577 	dout("sync_direct_write on file %p %lld~%u\n", file, pos,
578 	     (unsigned)count);
579 
580 	ret = filemap_write_and_wait_range(inode->i_mapping, pos, pos + count);
581 	if (ret < 0)
582 		return ret;
583 
584 	ret = invalidate_inode_pages2_range(inode->i_mapping,
585 					    pos >> PAGE_CACHE_SHIFT,
586 					    (pos + count) >> PAGE_CACHE_SHIFT);
587 	if (ret < 0)
588 		dout("invalidate_inode_pages2_range returned %d\n", ret);
589 
590 	flags = CEPH_OSD_FLAG_ORDERSNAP |
591 		CEPH_OSD_FLAG_ONDISK |
592 		CEPH_OSD_FLAG_WRITE;
593 
594 	while (iov_iter_count(from) > 0) {
595 		u64 len = iov_iter_single_seg_count(from);
596 		size_t start;
597 		ssize_t n;
598 
599 		vino = ceph_vino(inode);
600 		req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
601 					    vino, pos, &len, 0,
602 					    2,/*include a 'startsync' command*/
603 					    CEPH_OSD_OP_WRITE, flags, snapc,
604 					    ci->i_truncate_seq,
605 					    ci->i_truncate_size,
606 					    false);
607 		if (IS_ERR(req)) {
608 			ret = PTR_ERR(req);
609 			break;
610 		}
611 
612 		osd_req_op_init(req, 1, CEPH_OSD_OP_STARTSYNC, 0);
613 
614 		n = iov_iter_get_pages_alloc(from, &pages, len, &start);
615 		if (unlikely(n < 0)) {
616 			ret = n;
617 			ceph_osdc_put_request(req);
618 			break;
619 		}
620 
621 		num_pages = (n + start + PAGE_SIZE - 1) / PAGE_SIZE;
622 		/*
623 		 * throw out any page cache pages in this range. this
624 		 * may block.
625 		 */
626 		truncate_inode_pages_range(inode->i_mapping, pos,
627 				   (pos+n) | (PAGE_CACHE_SIZE-1));
628 		osd_req_op_extent_osd_data_pages(req, 0, pages, n, start,
629 						false, false);
630 
631 		/* BUG_ON(vino.snap != CEPH_NOSNAP); */
632 		ceph_osdc_build_request(req, pos, snapc, vino.snap, &mtime);
633 
634 		ret = ceph_osdc_start_request(&fsc->client->osdc, req, false);
635 		if (!ret)
636 			ret = ceph_osdc_wait_request(&fsc->client->osdc, req);
637 
638 		ceph_put_page_vector(pages, num_pages, false);
639 
640 		ceph_osdc_put_request(req);
641 		if (ret)
642 			break;
643 		pos += n;
644 		written += n;
645 		iov_iter_advance(from, n);
646 
647 		if (pos > i_size_read(inode)) {
648 			check_caps = ceph_inode_set_size(inode, pos);
649 			if (check_caps)
650 				ceph_check_caps(ceph_inode(inode),
651 						CHECK_CAPS_AUTHONLY,
652 						NULL);
653 		}
654 	}
655 
656 	if (ret != -EOLDSNAPC && written > 0) {
657 		iocb->ki_pos = pos;
658 		ret = written;
659 	}
660 	return ret;
661 }
662 
663 
664 /*
665  * Synchronous write, straight from __user pointer or user pages.
666  *
667  * If write spans object boundary, just do multiple writes.  (For a
668  * correct atomic write, we should e.g. take write locks on all
669  * objects, rollback on failure, etc.)
670  */
671 static ssize_t
672 ceph_sync_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos,
673 		struct ceph_snap_context *snapc)
674 {
675 	struct file *file = iocb->ki_filp;
676 	struct inode *inode = file_inode(file);
677 	struct ceph_inode_info *ci = ceph_inode(inode);
678 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
679 	struct ceph_vino vino;
680 	struct ceph_osd_request *req;
681 	struct page **pages;
682 	u64 len;
683 	int num_pages;
684 	int written = 0;
685 	int flags;
686 	int check_caps = 0;
687 	int ret;
688 	struct timespec mtime = CURRENT_TIME;
689 	size_t count = iov_iter_count(from);
690 
691 	if (ceph_snap(file_inode(file)) != CEPH_NOSNAP)
692 		return -EROFS;
693 
694 	dout("sync_write on file %p %lld~%u\n", file, pos, (unsigned)count);
695 
696 	ret = filemap_write_and_wait_range(inode->i_mapping, pos, pos + count);
697 	if (ret < 0)
698 		return ret;
699 
700 	ret = invalidate_inode_pages2_range(inode->i_mapping,
701 					    pos >> PAGE_CACHE_SHIFT,
702 					    (pos + count) >> PAGE_CACHE_SHIFT);
703 	if (ret < 0)
704 		dout("invalidate_inode_pages2_range returned %d\n", ret);
705 
706 	flags = CEPH_OSD_FLAG_ORDERSNAP |
707 		CEPH_OSD_FLAG_ONDISK |
708 		CEPH_OSD_FLAG_WRITE |
709 		CEPH_OSD_FLAG_ACK;
710 
711 	while ((len = iov_iter_count(from)) > 0) {
712 		size_t left;
713 		int n;
714 
715 		vino = ceph_vino(inode);
716 		req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
717 					    vino, pos, &len, 0, 1,
718 					    CEPH_OSD_OP_WRITE, flags, snapc,
719 					    ci->i_truncate_seq,
720 					    ci->i_truncate_size,
721 					    false);
722 		if (IS_ERR(req)) {
723 			ret = PTR_ERR(req);
724 			break;
725 		}
726 
727 		/*
728 		 * write from beginning of first page,
729 		 * regardless of io alignment
730 		 */
731 		num_pages = (len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
732 
733 		pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
734 		if (IS_ERR(pages)) {
735 			ret = PTR_ERR(pages);
736 			goto out;
737 		}
738 
739 		left = len;
740 		for (n = 0; n < num_pages; n++) {
741 			size_t plen = min_t(size_t, left, PAGE_SIZE);
742 			ret = copy_page_from_iter(pages[n], 0, plen, from);
743 			if (ret != plen) {
744 				ret = -EFAULT;
745 				break;
746 			}
747 			left -= ret;
748 		}
749 
750 		if (ret < 0) {
751 			ceph_release_page_vector(pages, num_pages);
752 			goto out;
753 		}
754 
755 		/* get a second commit callback */
756 		req->r_unsafe_callback = ceph_sync_write_unsafe;
757 		req->r_inode = inode;
758 
759 		osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0,
760 						false, true);
761 
762 		/* BUG_ON(vino.snap != CEPH_NOSNAP); */
763 		ceph_osdc_build_request(req, pos, snapc, vino.snap, &mtime);
764 
765 		ret = ceph_osdc_start_request(&fsc->client->osdc, req, false);
766 		if (!ret)
767 			ret = ceph_osdc_wait_request(&fsc->client->osdc, req);
768 
769 out:
770 		ceph_osdc_put_request(req);
771 		if (ret == 0) {
772 			pos += len;
773 			written += len;
774 
775 			if (pos > i_size_read(inode)) {
776 				check_caps = ceph_inode_set_size(inode, pos);
777 				if (check_caps)
778 					ceph_check_caps(ceph_inode(inode),
779 							CHECK_CAPS_AUTHONLY,
780 							NULL);
781 			}
782 		} else
783 			break;
784 	}
785 
786 	if (ret != -EOLDSNAPC && written > 0) {
787 		ret = written;
788 		iocb->ki_pos = pos;
789 	}
790 	return ret;
791 }
792 
793 /*
794  * Wrap generic_file_aio_read with checks for cap bits on the inode.
795  * Atomically grab references, so that those bits are not released
796  * back to the MDS mid-read.
797  *
798  * Hmm, the sync read case isn't actually async... should it be?
799  */
800 static ssize_t ceph_read_iter(struct kiocb *iocb, struct iov_iter *to)
801 {
802 	struct file *filp = iocb->ki_filp;
803 	struct ceph_file_info *fi = filp->private_data;
804 	size_t len = iov_iter_count(to);
805 	struct inode *inode = file_inode(filp);
806 	struct ceph_inode_info *ci = ceph_inode(inode);
807 	struct page *pinned_page = NULL;
808 	ssize_t ret;
809 	int want, got = 0;
810 	int retry_op = 0, read = 0;
811 
812 again:
813 	dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
814 	     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len, inode);
815 
816 	if (fi->fmode & CEPH_FILE_MODE_LAZY)
817 		want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
818 	else
819 		want = CEPH_CAP_FILE_CACHE;
820 	ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want, -1, &got, &pinned_page);
821 	if (ret < 0)
822 		return ret;
823 
824 	if ((got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0 ||
825 	    (iocb->ki_flags & IOCB_DIRECT) ||
826 	    (fi->flags & CEPH_F_SYNC)) {
827 
828 		dout("aio_sync_read %p %llx.%llx %llu~%u got cap refs on %s\n",
829 		     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,
830 		     ceph_cap_string(got));
831 
832 		if (ci->i_inline_version == CEPH_INLINE_NONE) {
833 			/* hmm, this isn't really async... */
834 			ret = ceph_sync_read(iocb, to, &retry_op);
835 		} else {
836 			retry_op = READ_INLINE;
837 		}
838 	} else {
839 		dout("aio_read %p %llx.%llx %llu~%u got cap refs on %s\n",
840 		     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,
841 		     ceph_cap_string(got));
842 
843 		ret = generic_file_read_iter(iocb, to);
844 	}
845 	dout("aio_read %p %llx.%llx dropping cap refs on %s = %d\n",
846 	     inode, ceph_vinop(inode), ceph_cap_string(got), (int)ret);
847 	if (pinned_page) {
848 		page_cache_release(pinned_page);
849 		pinned_page = NULL;
850 	}
851 	ceph_put_cap_refs(ci, got);
852 	if (retry_op && ret >= 0) {
853 		int statret;
854 		struct page *page = NULL;
855 		loff_t i_size;
856 		if (retry_op == READ_INLINE) {
857 			page = __page_cache_alloc(GFP_KERNEL);
858 			if (!page)
859 				return -ENOMEM;
860 		}
861 
862 		statret = __ceph_do_getattr(inode, page,
863 					    CEPH_STAT_CAP_INLINE_DATA, !!page);
864 		if (statret < 0) {
865 			 __free_page(page);
866 			if (statret == -ENODATA) {
867 				BUG_ON(retry_op != READ_INLINE);
868 				goto again;
869 			}
870 			return statret;
871 		}
872 
873 		i_size = i_size_read(inode);
874 		if (retry_op == READ_INLINE) {
875 			BUG_ON(ret > 0 || read > 0);
876 			if (iocb->ki_pos < i_size &&
877 			    iocb->ki_pos < PAGE_CACHE_SIZE) {
878 				loff_t end = min_t(loff_t, i_size,
879 						   iocb->ki_pos + len);
880 				end = min_t(loff_t, end, PAGE_CACHE_SIZE);
881 				if (statret < end)
882 					zero_user_segment(page, statret, end);
883 				ret = copy_page_to_iter(page,
884 						iocb->ki_pos & ~PAGE_MASK,
885 						end - iocb->ki_pos, to);
886 				iocb->ki_pos += ret;
887 				read += ret;
888 			}
889 			if (iocb->ki_pos < i_size && read < len) {
890 				size_t zlen = min_t(size_t, len - read,
891 						    i_size - iocb->ki_pos);
892 				ret = iov_iter_zero(zlen, to);
893 				iocb->ki_pos += ret;
894 				read += ret;
895 			}
896 			__free_pages(page, 0);
897 			return read;
898 		}
899 
900 		/* hit EOF or hole? */
901 		if (retry_op == CHECK_EOF && iocb->ki_pos < i_size &&
902 		    ret < len) {
903 			dout("sync_read hit hole, ppos %lld < size %lld"
904 			     ", reading more\n", iocb->ki_pos,
905 			     inode->i_size);
906 
907 			read += ret;
908 			len -= ret;
909 			retry_op = 0;
910 			goto again;
911 		}
912 	}
913 
914 	if (ret >= 0)
915 		ret += read;
916 
917 	return ret;
918 }
919 
920 /*
921  * Take cap references to avoid releasing caps to MDS mid-write.
922  *
923  * If we are synchronous, and write with an old snap context, the OSD
924  * may return EOLDSNAPC.  In that case, retry the write.. _after_
925  * dropping our cap refs and allowing the pending snap to logically
926  * complete _before_ this write occurs.
927  *
928  * If we are near ENOSPC, write synchronously.
929  */
930 static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from)
931 {
932 	struct file *file = iocb->ki_filp;
933 	struct ceph_file_info *fi = file->private_data;
934 	struct inode *inode = file_inode(file);
935 	struct ceph_inode_info *ci = ceph_inode(inode);
936 	struct ceph_osd_client *osdc =
937 		&ceph_sb_to_client(inode->i_sb)->client->osdc;
938 	struct ceph_cap_flush *prealloc_cf;
939 	ssize_t count, written = 0;
940 	int err, want, got;
941 	loff_t pos;
942 
943 	if (ceph_snap(inode) != CEPH_NOSNAP)
944 		return -EROFS;
945 
946 	prealloc_cf = ceph_alloc_cap_flush();
947 	if (!prealloc_cf)
948 		return -ENOMEM;
949 
950 	mutex_lock(&inode->i_mutex);
951 
952 	/* We can write back this queue in page reclaim */
953 	current->backing_dev_info = inode_to_bdi(inode);
954 
955 	if (iocb->ki_flags & IOCB_APPEND) {
956 		err = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE, false);
957 		if (err < 0)
958 			goto out;
959 	}
960 
961 	err = generic_write_checks(iocb, from);
962 	if (err <= 0)
963 		goto out;
964 
965 	pos = iocb->ki_pos;
966 	count = iov_iter_count(from);
967 	err = file_remove_privs(file);
968 	if (err)
969 		goto out;
970 
971 	err = file_update_time(file);
972 	if (err)
973 		goto out;
974 
975 	if (ci->i_inline_version != CEPH_INLINE_NONE) {
976 		err = ceph_uninline_data(file, NULL);
977 		if (err < 0)
978 			goto out;
979 	}
980 
981 retry_snap:
982 	if (ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_FULL)) {
983 		err = -ENOSPC;
984 		goto out;
985 	}
986 
987 	dout("aio_write %p %llx.%llx %llu~%zd getting caps. i_size %llu\n",
988 	     inode, ceph_vinop(inode), pos, count, inode->i_size);
989 	if (fi->fmode & CEPH_FILE_MODE_LAZY)
990 		want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
991 	else
992 		want = CEPH_CAP_FILE_BUFFER;
993 	got = 0;
994 	err = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, pos + count,
995 			    &got, NULL);
996 	if (err < 0)
997 		goto out;
998 
999 	dout("aio_write %p %llx.%llx %llu~%zd got cap refs on %s\n",
1000 	     inode, ceph_vinop(inode), pos, count, ceph_cap_string(got));
1001 
1002 	if ((got & (CEPH_CAP_FILE_BUFFER|CEPH_CAP_FILE_LAZYIO)) == 0 ||
1003 	    (iocb->ki_flags & IOCB_DIRECT) || (fi->flags & CEPH_F_SYNC)) {
1004 		struct ceph_snap_context *snapc;
1005 		struct iov_iter data;
1006 		mutex_unlock(&inode->i_mutex);
1007 
1008 		spin_lock(&ci->i_ceph_lock);
1009 		if (__ceph_have_pending_cap_snap(ci)) {
1010 			struct ceph_cap_snap *capsnap =
1011 					list_last_entry(&ci->i_cap_snaps,
1012 							struct ceph_cap_snap,
1013 							ci_item);
1014 			snapc = ceph_get_snap_context(capsnap->context);
1015 		} else {
1016 			BUG_ON(!ci->i_head_snapc);
1017 			snapc = ceph_get_snap_context(ci->i_head_snapc);
1018 		}
1019 		spin_unlock(&ci->i_ceph_lock);
1020 
1021 		/* we might need to revert back to that point */
1022 		data = *from;
1023 		if (iocb->ki_flags & IOCB_DIRECT)
1024 			written = ceph_sync_direct_write(iocb, &data, pos,
1025 							 snapc);
1026 		else
1027 			written = ceph_sync_write(iocb, &data, pos, snapc);
1028 		if (written == -EOLDSNAPC) {
1029 			dout("aio_write %p %llx.%llx %llu~%u"
1030 				"got EOLDSNAPC, retrying\n",
1031 				inode, ceph_vinop(inode),
1032 				pos, (unsigned)count);
1033 			mutex_lock(&inode->i_mutex);
1034 			goto retry_snap;
1035 		}
1036 		if (written > 0)
1037 			iov_iter_advance(from, written);
1038 		ceph_put_snap_context(snapc);
1039 	} else {
1040 		loff_t old_size = inode->i_size;
1041 		/*
1042 		 * No need to acquire the i_truncate_mutex. Because
1043 		 * the MDS revokes Fwb caps before sending truncate
1044 		 * message to us. We can't get Fwb cap while there
1045 		 * are pending vmtruncate. So write and vmtruncate
1046 		 * can not run at the same time
1047 		 */
1048 		written = generic_perform_write(file, from, pos);
1049 		if (likely(written >= 0))
1050 			iocb->ki_pos = pos + written;
1051 		if (inode->i_size > old_size)
1052 			ceph_fscache_update_objectsize(inode);
1053 		mutex_unlock(&inode->i_mutex);
1054 	}
1055 
1056 	if (written >= 0) {
1057 		int dirty;
1058 		spin_lock(&ci->i_ceph_lock);
1059 		ci->i_inline_version = CEPH_INLINE_NONE;
1060 		dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
1061 					       &prealloc_cf);
1062 		spin_unlock(&ci->i_ceph_lock);
1063 		if (dirty)
1064 			__mark_inode_dirty(inode, dirty);
1065 	}
1066 
1067 	dout("aio_write %p %llx.%llx %llu~%u  dropping cap refs on %s\n",
1068 	     inode, ceph_vinop(inode), pos, (unsigned)count,
1069 	     ceph_cap_string(got));
1070 	ceph_put_cap_refs(ci, got);
1071 
1072 	if (written >= 0 &&
1073 	    ((file->f_flags & O_SYNC) || IS_SYNC(file->f_mapping->host) ||
1074 	     ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_NEARFULL))) {
1075 		err = vfs_fsync_range(file, pos, pos + written - 1, 1);
1076 		if (err < 0)
1077 			written = err;
1078 	}
1079 
1080 	goto out_unlocked;
1081 
1082 out:
1083 	mutex_unlock(&inode->i_mutex);
1084 out_unlocked:
1085 	ceph_free_cap_flush(prealloc_cf);
1086 	current->backing_dev_info = NULL;
1087 	return written ? written : err;
1088 }
1089 
1090 /*
1091  * llseek.  be sure to verify file size on SEEK_END.
1092  */
1093 static loff_t ceph_llseek(struct file *file, loff_t offset, int whence)
1094 {
1095 	struct inode *inode = file->f_mapping->host;
1096 	int ret;
1097 
1098 	mutex_lock(&inode->i_mutex);
1099 
1100 	if (whence == SEEK_END || whence == SEEK_DATA || whence == SEEK_HOLE) {
1101 		ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE, false);
1102 		if (ret < 0) {
1103 			offset = ret;
1104 			goto out;
1105 		}
1106 	}
1107 
1108 	switch (whence) {
1109 	case SEEK_END:
1110 		offset += inode->i_size;
1111 		break;
1112 	case SEEK_CUR:
1113 		/*
1114 		 * Here we special-case the lseek(fd, 0, SEEK_CUR)
1115 		 * position-querying operation.  Avoid rewriting the "same"
1116 		 * f_pos value back to the file because a concurrent read(),
1117 		 * write() or lseek() might have altered it
1118 		 */
1119 		if (offset == 0) {
1120 			offset = file->f_pos;
1121 			goto out;
1122 		}
1123 		offset += file->f_pos;
1124 		break;
1125 	case SEEK_DATA:
1126 		if (offset >= inode->i_size) {
1127 			ret = -ENXIO;
1128 			goto out;
1129 		}
1130 		break;
1131 	case SEEK_HOLE:
1132 		if (offset >= inode->i_size) {
1133 			ret = -ENXIO;
1134 			goto out;
1135 		}
1136 		offset = inode->i_size;
1137 		break;
1138 	}
1139 
1140 	offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
1141 
1142 out:
1143 	mutex_unlock(&inode->i_mutex);
1144 	return offset;
1145 }
1146 
1147 static inline void ceph_zero_partial_page(
1148 	struct inode *inode, loff_t offset, unsigned size)
1149 {
1150 	struct page *page;
1151 	pgoff_t index = offset >> PAGE_CACHE_SHIFT;
1152 
1153 	page = find_lock_page(inode->i_mapping, index);
1154 	if (page) {
1155 		wait_on_page_writeback(page);
1156 		zero_user(page, offset & (PAGE_CACHE_SIZE - 1), size);
1157 		unlock_page(page);
1158 		page_cache_release(page);
1159 	}
1160 }
1161 
1162 static void ceph_zero_pagecache_range(struct inode *inode, loff_t offset,
1163 				      loff_t length)
1164 {
1165 	loff_t nearly = round_up(offset, PAGE_CACHE_SIZE);
1166 	if (offset < nearly) {
1167 		loff_t size = nearly - offset;
1168 		if (length < size)
1169 			size = length;
1170 		ceph_zero_partial_page(inode, offset, size);
1171 		offset += size;
1172 		length -= size;
1173 	}
1174 	if (length >= PAGE_CACHE_SIZE) {
1175 		loff_t size = round_down(length, PAGE_CACHE_SIZE);
1176 		truncate_pagecache_range(inode, offset, offset + size - 1);
1177 		offset += size;
1178 		length -= size;
1179 	}
1180 	if (length)
1181 		ceph_zero_partial_page(inode, offset, length);
1182 }
1183 
1184 static int ceph_zero_partial_object(struct inode *inode,
1185 				    loff_t offset, loff_t *length)
1186 {
1187 	struct ceph_inode_info *ci = ceph_inode(inode);
1188 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1189 	struct ceph_osd_request *req;
1190 	int ret = 0;
1191 	loff_t zero = 0;
1192 	int op;
1193 
1194 	if (!length) {
1195 		op = offset ? CEPH_OSD_OP_DELETE : CEPH_OSD_OP_TRUNCATE;
1196 		length = &zero;
1197 	} else {
1198 		op = CEPH_OSD_OP_ZERO;
1199 	}
1200 
1201 	req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1202 					ceph_vino(inode),
1203 					offset, length,
1204 					0, 1, op,
1205 					CEPH_OSD_FLAG_WRITE |
1206 					CEPH_OSD_FLAG_ONDISK,
1207 					NULL, 0, 0, false);
1208 	if (IS_ERR(req)) {
1209 		ret = PTR_ERR(req);
1210 		goto out;
1211 	}
1212 
1213 	ceph_osdc_build_request(req, offset, NULL, ceph_vino(inode).snap,
1214 				&inode->i_mtime);
1215 
1216 	ret = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1217 	if (!ret) {
1218 		ret = ceph_osdc_wait_request(&fsc->client->osdc, req);
1219 		if (ret == -ENOENT)
1220 			ret = 0;
1221 	}
1222 	ceph_osdc_put_request(req);
1223 
1224 out:
1225 	return ret;
1226 }
1227 
1228 static int ceph_zero_objects(struct inode *inode, loff_t offset, loff_t length)
1229 {
1230 	int ret = 0;
1231 	struct ceph_inode_info *ci = ceph_inode(inode);
1232 	s32 stripe_unit = ceph_file_layout_su(ci->i_layout);
1233 	s32 stripe_count = ceph_file_layout_stripe_count(ci->i_layout);
1234 	s32 object_size = ceph_file_layout_object_size(ci->i_layout);
1235 	u64 object_set_size = object_size * stripe_count;
1236 	u64 nearly, t;
1237 
1238 	/* round offset up to next period boundary */
1239 	nearly = offset + object_set_size - 1;
1240 	t = nearly;
1241 	nearly -= do_div(t, object_set_size);
1242 
1243 	while (length && offset < nearly) {
1244 		loff_t size = length;
1245 		ret = ceph_zero_partial_object(inode, offset, &size);
1246 		if (ret < 0)
1247 			return ret;
1248 		offset += size;
1249 		length -= size;
1250 	}
1251 	while (length >= object_set_size) {
1252 		int i;
1253 		loff_t pos = offset;
1254 		for (i = 0; i < stripe_count; ++i) {
1255 			ret = ceph_zero_partial_object(inode, pos, NULL);
1256 			if (ret < 0)
1257 				return ret;
1258 			pos += stripe_unit;
1259 		}
1260 		offset += object_set_size;
1261 		length -= object_set_size;
1262 	}
1263 	while (length) {
1264 		loff_t size = length;
1265 		ret = ceph_zero_partial_object(inode, offset, &size);
1266 		if (ret < 0)
1267 			return ret;
1268 		offset += size;
1269 		length -= size;
1270 	}
1271 	return ret;
1272 }
1273 
1274 static long ceph_fallocate(struct file *file, int mode,
1275 				loff_t offset, loff_t length)
1276 {
1277 	struct ceph_file_info *fi = file->private_data;
1278 	struct inode *inode = file_inode(file);
1279 	struct ceph_inode_info *ci = ceph_inode(inode);
1280 	struct ceph_osd_client *osdc =
1281 		&ceph_inode_to_client(inode)->client->osdc;
1282 	struct ceph_cap_flush *prealloc_cf;
1283 	int want, got = 0;
1284 	int dirty;
1285 	int ret = 0;
1286 	loff_t endoff = 0;
1287 	loff_t size;
1288 
1289 	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
1290 		return -EOPNOTSUPP;
1291 
1292 	if (!S_ISREG(inode->i_mode))
1293 		return -EOPNOTSUPP;
1294 
1295 	prealloc_cf = ceph_alloc_cap_flush();
1296 	if (!prealloc_cf)
1297 		return -ENOMEM;
1298 
1299 	mutex_lock(&inode->i_mutex);
1300 
1301 	if (ceph_snap(inode) != CEPH_NOSNAP) {
1302 		ret = -EROFS;
1303 		goto unlock;
1304 	}
1305 
1306 	if (ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_FULL) &&
1307 		!(mode & FALLOC_FL_PUNCH_HOLE)) {
1308 		ret = -ENOSPC;
1309 		goto unlock;
1310 	}
1311 
1312 	if (ci->i_inline_version != CEPH_INLINE_NONE) {
1313 		ret = ceph_uninline_data(file, NULL);
1314 		if (ret < 0)
1315 			goto unlock;
1316 	}
1317 
1318 	size = i_size_read(inode);
1319 	if (!(mode & FALLOC_FL_KEEP_SIZE))
1320 		endoff = offset + length;
1321 
1322 	if (fi->fmode & CEPH_FILE_MODE_LAZY)
1323 		want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
1324 	else
1325 		want = CEPH_CAP_FILE_BUFFER;
1326 
1327 	ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, endoff, &got, NULL);
1328 	if (ret < 0)
1329 		goto unlock;
1330 
1331 	if (mode & FALLOC_FL_PUNCH_HOLE) {
1332 		if (offset < size)
1333 			ceph_zero_pagecache_range(inode, offset, length);
1334 		ret = ceph_zero_objects(inode, offset, length);
1335 	} else if (endoff > size) {
1336 		truncate_pagecache_range(inode, size, -1);
1337 		if (ceph_inode_set_size(inode, endoff))
1338 			ceph_check_caps(ceph_inode(inode),
1339 				CHECK_CAPS_AUTHONLY, NULL);
1340 	}
1341 
1342 	if (!ret) {
1343 		spin_lock(&ci->i_ceph_lock);
1344 		ci->i_inline_version = CEPH_INLINE_NONE;
1345 		dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
1346 					       &prealloc_cf);
1347 		spin_unlock(&ci->i_ceph_lock);
1348 		if (dirty)
1349 			__mark_inode_dirty(inode, dirty);
1350 	}
1351 
1352 	ceph_put_cap_refs(ci, got);
1353 unlock:
1354 	mutex_unlock(&inode->i_mutex);
1355 	ceph_free_cap_flush(prealloc_cf);
1356 	return ret;
1357 }
1358 
1359 const struct file_operations ceph_file_fops = {
1360 	.open = ceph_open,
1361 	.release = ceph_release,
1362 	.llseek = ceph_llseek,
1363 	.read_iter = ceph_read_iter,
1364 	.write_iter = ceph_write_iter,
1365 	.mmap = ceph_mmap,
1366 	.fsync = ceph_fsync,
1367 	.lock = ceph_lock,
1368 	.flock = ceph_flock,
1369 	.splice_read = generic_file_splice_read,
1370 	.splice_write = iter_file_splice_write,
1371 	.unlocked_ioctl = ceph_ioctl,
1372 	.compat_ioctl	= ceph_ioctl,
1373 	.fallocate	= ceph_fallocate,
1374 };
1375 
1376