1 #include "ceph_debug.h"
3 #include <linux/sched.h>
4 #include <linux/file.h>
5 #include <linux/namei.h>
6 #include <linux/writeback.h>
9 #include "mds_client.h"
12 * Ceph file operations
14 * Implement basic open/close functionality, and implement
17 * We implement three modes of file I/O:
18 * - buffered uses the generic_file_aio_{read,write} helpers
20 * - synchronous is used when there is multi-client read/write
21 * sharing, avoids the page cache, and synchronously waits for an
24 * - direct io takes the variant of the sync path that references
25 * user pages directly.
27 * fsync() flushes and waits on dirty pages, but just queues metadata
28 * for writeback: since the MDS can recover size and mtime there is no
29 * need to wait for MDS acknowledgement.
34 * Prepare an open request. Preallocate ceph_cap to avoid an
35 * inopportune ENOMEM later.
37 static struct ceph_mds_request *
38 prepare_open_request(struct super_block *sb, int flags, int create_mode)
40 struct ceph_client *client = ceph_sb_to_client(sb);
41 struct ceph_mds_client *mdsc = &client->mdsc;
42 struct ceph_mds_request *req;
43 int want_auth = USE_ANY_MDS;
44 int op = (flags & O_CREAT) ? CEPH_MDS_OP_CREATE : CEPH_MDS_OP_OPEN;
46 if (flags & (O_WRONLY|O_RDWR|O_CREAT|O_TRUNC))
47 want_auth = USE_AUTH_MDS;
49 req = ceph_mdsc_create_request(mdsc, op, want_auth);
52 req->r_fmode = ceph_flags_to_mode(flags);
53 req->r_args.open.flags = cpu_to_le32(flags);
54 req->r_args.open.mode = cpu_to_le32(create_mode);
55 req->r_args.open.preferred = cpu_to_le32(-1);
61 * initialize private struct file data.
62 * if we fail, clean up by dropping fmode reference on the ceph_inode
64 static int ceph_init_file(struct inode *inode, struct file *file, int fmode)
66 struct ceph_file_info *cf;
69 switch (inode->i_mode & S_IFMT) {
72 dout("init_file %p %p 0%o (regular)\n", inode, file,
74 cf = kmem_cache_alloc(ceph_file_cachep, GFP_NOFS | __GFP_ZERO);
76 ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
81 file->private_data = cf;
82 BUG_ON(inode->i_fop->release != ceph_release);
86 dout("init_file %p %p 0%o (symlink)\n", inode, file,
88 ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
92 dout("init_file %p %p 0%o (special)\n", inode, file,
95 * we need to drop the open ref now, since we don't
96 * have .release set to ceph_release.
98 ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
99 BUG_ON(inode->i_fop->release == ceph_release);
101 /* call the proper open fop */
102 ret = inode->i_fop->open(inode, file);
108 * If the filp already has private_data, that means the file was
109 * already opened by intent during lookup, and we do nothing.
111 * If we already have the requisite capabilities, we can satisfy
112 * the open request locally (no need to request new caps from the
113 * MDS). We do, however, need to inform the MDS (asynchronously)
114 * if our wanted caps set expands.
116 int ceph_open(struct inode *inode, struct file *file)
118 struct ceph_inode_info *ci = ceph_inode(inode);
119 struct ceph_client *client = ceph_sb_to_client(inode->i_sb);
120 struct ceph_mds_client *mdsc = &client->mdsc;
121 struct ceph_mds_request *req;
122 struct ceph_file_info *cf = file->private_data;
123 struct inode *parent_inode = file->f_dentry->d_parent->d_inode;
125 int flags, fmode, wanted;
128 dout("open file %p is already opened\n", file);
132 /* filter out O_CREAT|O_EXCL; vfs did that already. yuck. */
133 flags = file->f_flags & ~(O_CREAT|O_EXCL);
134 if (S_ISDIR(inode->i_mode))
135 flags = O_DIRECTORY; /* mds likes to know */
137 dout("open inode %p ino %llx.%llx file %p flags %d (%d)\n", inode,
138 ceph_vinop(inode), file, flags, file->f_flags);
139 fmode = ceph_flags_to_mode(flags);
140 wanted = ceph_caps_for_mode(fmode);
142 /* snapped files are read-only */
143 if (ceph_snap(inode) != CEPH_NOSNAP && (file->f_mode & FMODE_WRITE))
146 /* trivially open snapdir */
147 if (ceph_snap(inode) == CEPH_SNAPDIR) {
148 spin_lock(&inode->i_lock);
149 __ceph_get_fmode(ci, fmode);
150 spin_unlock(&inode->i_lock);
151 return ceph_init_file(inode, file, fmode);
155 * No need to block if we have any caps. Update wanted set
158 spin_lock(&inode->i_lock);
159 if (__ceph_is_any_real_caps(ci)) {
160 int mds_wanted = __ceph_caps_mds_wanted(ci);
161 int issued = __ceph_caps_issued(ci, NULL);
163 dout("open %p fmode %d want %s issued %s using existing\n",
164 inode, fmode, ceph_cap_string(wanted),
165 ceph_cap_string(issued));
166 __ceph_get_fmode(ci, fmode);
167 spin_unlock(&inode->i_lock);
170 if ((issued & wanted) != wanted &&
171 (mds_wanted & wanted) != wanted &&
172 ceph_snap(inode) != CEPH_SNAPDIR)
173 ceph_check_caps(ci, 0, NULL);
175 return ceph_init_file(inode, file, fmode);
176 } else if (ceph_snap(inode) != CEPH_NOSNAP &&
177 (ci->i_snap_caps & wanted) == wanted) {
178 __ceph_get_fmode(ci, fmode);
179 spin_unlock(&inode->i_lock);
180 return ceph_init_file(inode, file, fmode);
182 spin_unlock(&inode->i_lock);
184 dout("open fmode %d wants %s\n", fmode, ceph_cap_string(wanted));
185 req = prepare_open_request(inode->i_sb, flags, 0);
190 req->r_inode = igrab(inode);
192 err = ceph_mdsc_do_request(mdsc, parent_inode, req);
194 err = ceph_init_file(inode, file, req->r_fmode);
195 ceph_mdsc_put_request(req);
196 dout("open result=%d on %llx.%llx\n", err, ceph_vinop(inode));
203 * Do a lookup + open with a single request.
205 * If this succeeds, but some subsequent check in the vfs
206 * may_open() fails, the struct *file gets cleaned up (i.e.
207 * ceph_release gets called). So fear not!
211 * path_lookup_open -> LOOKUP_OPEN
212 * path_lookup_create -> LOOKUP_OPEN|LOOKUP_CREATE
214 struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
215 struct nameidata *nd, int mode,
218 struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
219 struct ceph_mds_client *mdsc = &client->mdsc;
220 struct file *file = nd->intent.open.file;
221 struct inode *parent_inode = get_dentry_parent_inode(file->f_dentry);
222 struct ceph_mds_request *req;
224 int flags = nd->intent.open.flags - 1; /* silly vfs! */
226 dout("ceph_lookup_open dentry %p '%.*s' flags %d mode 0%o\n",
227 dentry, dentry->d_name.len, dentry->d_name.name, flags, mode);
230 req = prepare_open_request(dir->i_sb, flags, mode);
232 return ERR_PTR(PTR_ERR(req));
233 req->r_dentry = dget(dentry);
235 if (flags & O_CREAT) {
236 req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
237 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
239 req->r_locked_dir = dir; /* caller holds dir->i_mutex */
240 err = ceph_mdsc_do_request(mdsc, parent_inode, req);
241 dentry = ceph_finish_lookup(req, dentry, err);
242 if (!err && (flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
243 err = ceph_handle_notrace_create(dir, dentry);
245 err = ceph_init_file(req->r_dentry->d_inode, file,
247 ceph_mdsc_put_request(req);
248 dout("ceph_lookup_open result=%p\n", dentry);
252 int ceph_release(struct inode *inode, struct file *file)
254 struct ceph_inode_info *ci = ceph_inode(inode);
255 struct ceph_file_info *cf = file->private_data;
257 dout("release inode %p file %p\n", inode, file);
258 ceph_put_fmode(ci, cf->fmode);
259 if (cf->last_readdir)
260 ceph_mdsc_put_request(cf->last_readdir);
261 kfree(cf->last_name);
264 kmem_cache_free(ceph_file_cachep, cf);
269 * build a vector of user pages
271 static struct page **get_direct_page_vector(const char __user *data,
273 loff_t off, size_t len)
278 pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
280 return ERR_PTR(-ENOMEM);
282 down_read(¤t->mm->mmap_sem);
283 rc = get_user_pages(current, current->mm, (unsigned long)data,
284 num_pages, 0, 0, pages, NULL);
285 up_read(¤t->mm->mmap_sem);
295 static void put_page_vector(struct page **pages, int num_pages)
299 for (i = 0; i < num_pages; i++)
304 void ceph_release_page_vector(struct page **pages, int num_pages)
308 for (i = 0; i < num_pages; i++)
309 __free_pages(pages[i], 0);
314 * allocate a vector new pages
316 static struct page **alloc_page_vector(int num_pages)
321 pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
323 return ERR_PTR(-ENOMEM);
324 for (i = 0; i < num_pages; i++) {
325 pages[i] = alloc_page(GFP_NOFS);
326 if (pages[i] == NULL) {
327 ceph_release_page_vector(pages, i);
328 return ERR_PTR(-ENOMEM);
335 * copy user data into a page vector
337 static int copy_user_to_page_vector(struct page **pages,
338 const char __user *data,
339 loff_t off, size_t len)
342 int po = off & ~PAGE_CACHE_MASK;
347 l = min_t(int, PAGE_CACHE_SIZE-po, left);
348 bad = copy_from_user(page_address(pages[i]) + po, data, l);
354 if (po == PAGE_CACHE_SIZE) {
363 * copy user data from a page vector into a user pointer
365 static int copy_page_vector_to_user(struct page **pages, char __user *data,
366 loff_t off, size_t len)
369 int po = off & ~PAGE_CACHE_MASK;
374 l = min_t(int, left, PAGE_CACHE_SIZE-po);
375 bad = copy_to_user(data, page_address(pages[i]) + po, l);
382 if (po == PAGE_CACHE_SIZE)
391 * Zero an extent within a page vector. Offset is relative to the
392 * start of the first page.
394 static void zero_page_vector_range(int off, int len, struct page **pages)
396 int i = off >> PAGE_CACHE_SHIFT;
398 off &= ~PAGE_CACHE_MASK;
400 dout("zero_page_vector_page %u~%u\n", off, len);
402 /* leading partial page? */
404 int end = min((int)PAGE_CACHE_SIZE, off + len);
405 dout("zeroing %d %p head from %d\n", i, pages[i],
407 zero_user_segment(pages[i], off, end);
411 while (len >= PAGE_CACHE_SIZE) {
412 dout("zeroing %d %p len=%d\n", i, pages[i], len);
413 zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
414 len -= PAGE_CACHE_SIZE;
417 /* trailing partial page? */
419 dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
420 zero_user_segment(pages[i], 0, len);
426 * Read a range of bytes striped over one or more objects. Iterate over
427 * objects we stripe over. (That's not atomic, but good enough for now.)
429 * If we get a short result from the OSD, check against i_size; we need to
430 * only return a short read to the caller if we hit EOF.
432 static int striped_read(struct inode *inode,
434 struct page **pages, int num_pages,
437 struct ceph_client *client = ceph_inode_to_client(inode);
438 struct ceph_inode_info *ci = ceph_inode(inode);
440 int page_off = off & ~PAGE_CACHE_MASK; /* first byte's offset in page */
441 int left, pages_left;
443 struct page **page_pos;
445 bool hit_stripe, was_short;
448 * we may need to do multiple reads. not atomic, unfortunately.
453 pages_left = num_pages;
458 ret = ceph_osdc_readpages(&client->osdc, ceph_vino(inode),
459 &ci->i_layout, pos, &this_len,
462 page_pos, pages_left);
463 hit_stripe = this_len < left;
464 was_short = ret >= 0 && ret < this_len;
467 dout("striped_read %llu~%u (read %u) got %d%s%s\n", pos, left, read,
468 ret, hit_stripe ? " HITSTRIPE" : "", was_short ? " SHORT" : "");
472 ((pos & ~PAGE_CACHE_MASK) + ret) >> PAGE_CACHE_SHIFT;
474 if (read < pos - off) {
475 dout(" zero gap %llu to %llu\n", off + read, pos);
476 zero_page_vector_range(page_off + read,
477 pos - off - read, pages);
482 page_pos += didpages;
483 pages_left -= didpages;
486 if (left && hit_stripe)
491 /* was original extent fully inside i_size? */
492 if (pos + left <= inode->i_size) {
494 zero_page_vector_range(page_off + read, len - read,
507 dout("striped_read returns %d\n", ret);
512 * Completely synchronous read and write methods. Direct from __user
513 * buffer to osd, or directly to user pages (if O_DIRECT).
515 * If the read spans object boundary, just do multiple reads.
517 static ssize_t ceph_sync_read(struct file *file, char __user *data,
518 unsigned len, loff_t *poff, int *checkeof)
520 struct inode *inode = file->f_dentry->d_inode;
523 int num_pages = calc_pages_for(off, len);
526 dout("sync_read on file %p %llu~%u %s\n", file, off, len,
527 (file->f_flags & O_DIRECT) ? "O_DIRECT" : "");
529 if (file->f_flags & O_DIRECT) {
530 pages = get_direct_page_vector(data, num_pages, off, len);
533 * flush any page cache pages in this range. this
534 * will make concurrent normal and O_DIRECT io slow,
535 * but it will at least behave sensibly when they are
539 pages = alloc_page_vector(num_pages);
542 return PTR_ERR(pages);
544 ret = filemap_write_and_wait(inode->i_mapping);
548 ret = striped_read(inode, off, len, pages, num_pages, checkeof);
550 if (ret >= 0 && (file->f_flags & O_DIRECT) == 0)
551 ret = copy_page_vector_to_user(pages, data, off, ret);
556 if (file->f_flags & O_DIRECT)
557 put_page_vector(pages, num_pages);
559 ceph_release_page_vector(pages, num_pages);
560 dout("sync_read result %d\n", ret);
565 * Write commit callback, called if we requested both an ACK and
566 * ONDISK commit reply from the OSD.
568 static void sync_write_commit(struct ceph_osd_request *req,
569 struct ceph_msg *msg)
571 struct ceph_inode_info *ci = ceph_inode(req->r_inode);
573 dout("sync_write_commit %p tid %llu\n", req, req->r_tid);
574 spin_lock(&ci->i_unsafe_lock);
575 list_del_init(&req->r_unsafe_item);
576 spin_unlock(&ci->i_unsafe_lock);
577 ceph_put_cap_refs(ci, CEPH_CAP_FILE_WR);
581 * Synchronous write, straight from __user pointer or user pages (if
584 * If write spans object boundary, just do multiple writes. (For a
585 * correct atomic write, we should e.g. take write locks on all
586 * objects, rollback on failure, etc.)
588 static ssize_t ceph_sync_write(struct file *file, const char __user *data,
589 size_t left, loff_t *offset)
591 struct inode *inode = file->f_dentry->d_inode;
592 struct ceph_inode_info *ci = ceph_inode(inode);
593 struct ceph_client *client = ceph_inode_to_client(inode);
594 struct ceph_osd_request *req;
597 long long unsigned pos;
604 struct timespec mtime = CURRENT_TIME;
606 if (ceph_snap(file->f_dentry->d_inode) != CEPH_NOSNAP)
609 dout("sync_write on file %p %lld~%u %s\n", file, *offset,
610 (unsigned)left, (file->f_flags & O_DIRECT) ? "O_DIRECT" : "");
612 if (file->f_flags & O_APPEND)
613 pos = i_size_read(inode);
617 ret = filemap_write_and_wait_range(inode->i_mapping, pos, pos + left);
621 ret = invalidate_inode_pages2_range(inode->i_mapping,
622 pos >> PAGE_CACHE_SHIFT,
623 (pos + left) >> PAGE_CACHE_SHIFT);
625 dout("invalidate_inode_pages2_range returned %d\n", ret);
627 flags = CEPH_OSD_FLAG_ORDERSNAP |
628 CEPH_OSD_FLAG_ONDISK |
630 if ((file->f_flags & (O_SYNC|O_DIRECT)) == 0)
631 flags |= CEPH_OSD_FLAG_ACK;
636 * we may need to do multiple writes here if we span an object
637 * boundary. this isn't atomic, unfortunately. :(
641 req = ceph_osdc_new_request(&client->osdc, &ci->i_layout,
642 ceph_vino(inode), pos, &len,
643 CEPH_OSD_OP_WRITE, flags,
644 ci->i_snap_realm->cached_context,
646 ci->i_truncate_seq, ci->i_truncate_size,
651 num_pages = calc_pages_for(pos, len);
653 if (file->f_flags & O_DIRECT) {
654 pages = get_direct_page_vector(data, num_pages, pos, len);
656 ret = PTR_ERR(pages);
661 * throw out any page cache pages in this range. this
664 truncate_inode_pages_range(inode->i_mapping, pos, pos+len);
666 pages = alloc_page_vector(num_pages);
668 ret = PTR_ERR(pages);
671 ret = copy_user_to_page_vector(pages, data, pos, len);
673 ceph_release_page_vector(pages, num_pages);
677 if ((file->f_flags & O_SYNC) == 0) {
678 /* get a second commit callback */
679 req->r_safe_callback = sync_write_commit;
680 req->r_own_pages = 1;
683 req->r_pages = pages;
684 req->r_num_pages = num_pages;
685 req->r_inode = inode;
687 ret = ceph_osdc_start_request(&client->osdc, req, false);
689 if (req->r_safe_callback) {
691 * Add to inode unsafe list only after we
692 * start_request so that a tid has been assigned.
694 spin_lock(&ci->i_unsafe_lock);
695 list_add(&ci->i_unsafe_writes, &req->r_unsafe_item);
696 spin_unlock(&ci->i_unsafe_lock);
697 ceph_get_cap_refs(ci, CEPH_CAP_FILE_WR);
699 ret = ceph_osdc_wait_request(&client->osdc, req);
702 if (file->f_flags & O_DIRECT)
703 put_page_vector(pages, num_pages);
704 else if (file->f_flags & O_SYNC)
705 ceph_release_page_vector(pages, num_pages);
708 ceph_osdc_put_request(req);
718 if (pos > i_size_read(inode))
719 check_caps = ceph_inode_set_size(inode, pos);
721 ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY,
728 * Wrap generic_file_aio_read with checks for cap bits on the inode.
729 * Atomically grab references, so that those bits are not released
730 * back to the MDS mid-read.
732 * Hmm, the sync read case isn't actually async... should it be?
734 static ssize_t ceph_aio_read(struct kiocb *iocb, const struct iovec *iov,
735 unsigned long nr_segs, loff_t pos)
737 struct file *filp = iocb->ki_filp;
738 loff_t *ppos = &iocb->ki_pos;
739 size_t len = iov->iov_len;
740 struct inode *inode = filp->f_dentry->d_inode;
741 struct ceph_inode_info *ci = ceph_inode(inode);
742 void *base = iov->iov_base;
745 int checkeof = 0, read = 0;
747 dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
748 inode, ceph_vinop(inode), pos, (unsigned)len, inode);
750 __ceph_do_pending_vmtruncate(inode);
751 ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, CEPH_CAP_FILE_CACHE,
755 dout("aio_read %p %llx.%llx %llu~%u got cap refs on %s\n",
756 inode, ceph_vinop(inode), pos, (unsigned)len,
757 ceph_cap_string(got));
759 if ((got & CEPH_CAP_FILE_CACHE) == 0 ||
760 (iocb->ki_filp->f_flags & O_DIRECT) ||
761 (inode->i_sb->s_flags & MS_SYNCHRONOUS))
762 /* hmm, this isn't really async... */
763 ret = ceph_sync_read(filp, base, len, ppos, &checkeof);
765 ret = generic_file_aio_read(iocb, iov, nr_segs, pos);
768 dout("aio_read %p %llx.%llx dropping cap refs on %s = %d\n",
769 inode, ceph_vinop(inode), ceph_cap_string(got), (int)ret);
770 ceph_put_cap_refs(ci, got);
772 if (checkeof && ret >= 0) {
773 int statret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE);
775 /* hit EOF or hole? */
776 if (statret == 0 && *ppos < inode->i_size) {
777 dout("aio_read sync_read hit hole, reading more\n");
792 * Take cap references to avoid releasing caps to MDS mid-write.
794 * If we are synchronous, and write with an old snap context, the OSD
795 * may return EOLDSNAPC. In that case, retry the write.. _after_
796 * dropping our cap refs and allowing the pending snap to logically
797 * complete _before_ this write occurs.
799 * If we are near ENOSPC, write synchronously.
801 static ssize_t ceph_aio_write(struct kiocb *iocb, const struct iovec *iov,
802 unsigned long nr_segs, loff_t pos)
804 struct file *file = iocb->ki_filp;
805 struct inode *inode = file->f_dentry->d_inode;
806 struct ceph_inode_info *ci = ceph_inode(inode);
807 struct ceph_osd_client *osdc = &ceph_client(inode->i_sb)->osdc;
808 loff_t endoff = pos + iov->iov_len;
812 if (ceph_snap(inode) != CEPH_NOSNAP)
816 if (ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_FULL))
818 __ceph_do_pending_vmtruncate(inode);
819 dout("aio_write %p %llx.%llx %llu~%u getting caps. i_size %llu\n",
820 inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len,
822 ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, CEPH_CAP_FILE_BUFFER,
827 dout("aio_write %p %llx.%llx %llu~%u got cap refs on %s\n",
828 inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len,
829 ceph_cap_string(got));
831 if ((got & CEPH_CAP_FILE_BUFFER) == 0 ||
832 (iocb->ki_filp->f_flags & O_DIRECT) ||
833 (inode->i_sb->s_flags & MS_SYNCHRONOUS)) {
834 ret = ceph_sync_write(file, iov->iov_base, iov->iov_len,
837 ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
839 if ((ret >= 0 || ret == -EIOCBQUEUED) &&
840 ((file->f_flags & O_SYNC) || IS_SYNC(file->f_mapping->host)
841 || ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_NEARFULL))) {
842 err = vfs_fsync_range(file, file->f_path.dentry,
843 pos, pos + ret - 1, 1);
849 spin_lock(&inode->i_lock);
850 __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR);
851 spin_unlock(&inode->i_lock);
855 dout("aio_write %p %llx.%llx %llu~%u dropping cap refs on %s\n",
856 inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len,
857 ceph_cap_string(got));
858 ceph_put_cap_refs(ci, got);
860 if (ret == -EOLDSNAPC) {
861 dout("aio_write %p %llx.%llx %llu~%u got EOLDSNAPC, retrying\n",
862 inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len);
870 * llseek. be sure to verify file size on SEEK_END.
872 static loff_t ceph_llseek(struct file *file, loff_t offset, int origin)
874 struct inode *inode = file->f_mapping->host;
877 mutex_lock(&inode->i_mutex);
878 __ceph_do_pending_vmtruncate(inode);
881 ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE);
886 offset += inode->i_size;
890 * Here we special-case the lseek(fd, 0, SEEK_CUR)
891 * position-querying operation. Avoid rewriting the "same"
892 * f_pos value back to the file because a concurrent read(),
893 * write() or lseek() might have altered it
896 offset = file->f_pos;
899 offset += file->f_pos;
903 if (offset < 0 || offset > inode->i_sb->s_maxbytes) {
908 /* Special lock needed here? */
909 if (offset != file->f_pos) {
910 file->f_pos = offset;
915 mutex_unlock(&inode->i_mutex);
919 const struct file_operations ceph_file_fops = {
921 .release = ceph_release,
922 .llseek = ceph_llseek,
923 .read = do_sync_read,
924 .write = do_sync_write,
925 .aio_read = ceph_aio_read,
926 .aio_write = ceph_aio_write,
929 .splice_read = generic_file_splice_read,
930 .splice_write = generic_file_splice_write,
931 .unlocked_ioctl = ceph_ioctl,
932 .compat_ioctl = ceph_ioctl,