4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright (c) 2011, Lawrence Livermore National Security, LLC.
26 #include <sys/dmu_objset.h>
27 #include <sys/zfs_vfsops.h>
28 #include <sys/zfs_vnops.h>
29 #include <sys/zfs_znode.h>
34 zpl_open(struct inode
*ip
, struct file
*filp
)
39 error
= generic_file_open(ip
, filp
);
44 error
= -zfs_open(ip
, filp
->f_mode
, filp
->f_flags
, cr
);
46 ASSERT3S(error
, <=, 0);
52 zpl_release(struct inode
*ip
, struct file
*filp
)
57 if (ITOZ(ip
)->z_atime_dirty
)
61 error
= -zfs_close(ip
, filp
->f_flags
, cr
);
63 ASSERT3S(error
, <=, 0);
69 zpl_iterate(struct file
*filp
, struct dir_context
*ctx
)
71 struct dentry
*dentry
= filp
->f_path
.dentry
;
76 error
= -zfs_readdir(dentry
->d_inode
, ctx
, cr
);
78 ASSERT3S(error
, <=, 0);
83 #if !defined(HAVE_VFS_ITERATE)
85 zpl_readdir(struct file
*filp
, void *dirent
, filldir_t filldir
)
87 struct dir_context ctx
= DIR_CONTEXT_INIT(dirent
, filldir
, filp
->f_pos
);
90 error
= zpl_iterate(filp
, &ctx
);
91 filp
->f_pos
= ctx
.pos
;
95 #endif /* HAVE_VFS_ITERATE */
97 #if defined(HAVE_FSYNC_WITH_DENTRY)
99 * Linux 2.6.x - 2.6.34 API,
100 * Through 2.6.34 the nfsd kernel server would pass a NULL 'file struct *'
101 * to the fops->fsync() hook. For this reason, we must be careful not to
102 * use filp unconditionally.
105 zpl_fsync(struct file
*filp
, struct dentry
*dentry
, int datasync
)
111 error
= -zfs_fsync(dentry
->d_inode
, datasync
, cr
);
113 ASSERT3S(error
, <=, 0);
118 #elif defined(HAVE_FSYNC_WITHOUT_DENTRY)
120 * Linux 2.6.35 - 3.0 API,
121 * As of 2.6.35 the dentry argument to the fops->fsync() hook was deemed
122 * redundant. The dentry is still accessible via filp->f_path.dentry,
123 * and we are guaranteed that filp will never be NULL.
126 zpl_fsync(struct file
*filp
, int datasync
)
128 struct inode
*inode
= filp
->f_mapping
->host
;
133 error
= -zfs_fsync(inode
, datasync
, cr
);
135 ASSERT3S(error
, <=, 0);
140 #elif defined(HAVE_FSYNC_RANGE)
142 * Linux 3.1 - 3.x API,
143 * As of 3.1 the responsibility to call filemap_write_and_wait_range() has
144 * been pushed down in to the .fsync() vfs hook. Additionally, the i_mutex
145 * lock is no longer held by the caller, for zfs we don't require the lock
146 * to be held so we don't acquire it.
149 zpl_fsync(struct file
*filp
, loff_t start
, loff_t end
, int datasync
)
151 struct inode
*inode
= filp
->f_mapping
->host
;
155 error
= filemap_write_and_wait_range(inode
->i_mapping
, start
, end
);
160 error
= -zfs_fsync(inode
, datasync
, cr
);
162 ASSERT3S(error
, <=, 0);
167 #error "Unsupported fops->fsync() implementation"
171 zpl_read_common(struct inode
*ip
, const char *buf
, size_t len
, loff_t pos
,
172 uio_seg_t segment
, int flags
, cred_t
*cr
)
179 iov
.iov_base
= (void *)buf
;
185 uio
.uio_loffset
= pos
;
186 uio
.uio_limit
= MAXOFFSET_T
;
187 uio
.uio_segflg
= segment
;
189 error
= -zfs_read(ip
, &uio
, flags
, cr
);
193 read
= len
- uio
.uio_resid
;
194 task_io_account_read(read
);
200 zpl_read(struct file
*filp
, char __user
*buf
, size_t len
, loff_t
*ppos
)
206 read
= zpl_read_common(filp
->f_mapping
->host
, buf
, len
, *ppos
,
207 UIO_USERSPACE
, filp
->f_flags
, cr
);
218 zpl_write_common(struct inode
*ip
, const char *buf
, size_t len
, loff_t pos
,
219 uio_seg_t segment
, int flags
, cred_t
*cr
)
226 iov
.iov_base
= (void *)buf
;
232 uio
.uio_loffset
= pos
;
233 uio
.uio_limit
= MAXOFFSET_T
;
234 uio
.uio_segflg
= segment
;
236 error
= -zfs_write(ip
, &uio
, flags
, cr
);
240 wrote
= len
- uio
.uio_resid
;
241 task_io_account_write(wrote
);
247 zpl_write(struct file
*filp
, const char __user
*buf
, size_t len
, loff_t
*ppos
)
253 wrote
= zpl_write_common(filp
->f_mapping
->host
, buf
, len
, *ppos
,
254 UIO_USERSPACE
, filp
->f_flags
, cr
);
265 zpl_llseek(struct file
*filp
, loff_t offset
, int whence
)
267 #if defined(SEEK_HOLE) && defined(SEEK_DATA)
268 if (whence
== SEEK_DATA
|| whence
== SEEK_HOLE
) {
269 struct inode
*ip
= filp
->f_mapping
->host
;
270 loff_t maxbytes
= ip
->i_sb
->s_maxbytes
;
274 error
= -zfs_holey(ip
, whence
, &offset
);
276 error
= lseek_execute(filp
, ip
, offset
, maxbytes
);
277 spl_inode_unlock(ip
);
281 #endif /* SEEK_HOLE && SEEK_DATA */
283 return (generic_file_llseek(filp
, offset
, whence
));
287 * It's worth taking a moment to describe how mmap is implemented
288 * for zfs because it differs considerably from other Linux filesystems.
289 * However, this issue is handled the same way under OpenSolaris.
291 * The issue is that by design zfs bypasses the Linux page cache and
292 * leaves all caching up to the ARC. This has been shown to work
293 * well for the common read(2)/write(2) case. However, mmap(2)
294 * is problem because it relies on being tightly integrated with the
295 * page cache. To handle this we cache mmap'ed files twice, once in
296 * the ARC and a second time in the page cache. The code is careful
297 * to keep both copies synchronized.
299 * When a file with an mmap'ed region is written to using write(2)
300 * both the data in the ARC and existing pages in the page cache
301 * are updated. For a read(2) data will be read first from the page
302 * cache then the ARC if needed. Neither a write(2) or read(2) will
303 * will ever result in new pages being added to the page cache.
305 * New pages are added to the page cache only via .readpage() which
306 * is called when the vfs needs to read a page off disk to back the
307 * virtual memory region. These pages may be modified without
308 * notifying the ARC and will be written out periodically via
309 * .writepage(). This will occur due to either a sync or the usual
310 * page aging behavior. Note because a read(2) of a mmap'ed file
311 * will always check the page cache first even when the ARC is out
312 * of date correct data will still be returned.
314 * While this implementation ensures correct behavior it does have
315 * have some drawbacks. The most obvious of which is that it
316 * increases the required memory footprint when access mmap'ed
317 * files. It also adds additional complexity to the code keeping
318 * both caches synchronized.
320 * Longer term it may be possible to cleanly resolve this wart by
321 * mapping page cache pages directly on to the ARC buffers. The
322 * Linux address space operations are flexible enough to allow
323 * selection of which pages back a particular index. The trick
324 * would be working out the details of which subsystem is in
325 * charge, the ARC, the page cache, or both. It may also prove
326 * helpful to move the ARC buffers to a scatter-gather lists
327 * rather than a vmalloc'ed region.
330 zpl_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
332 struct inode
*ip
= filp
->f_mapping
->host
;
333 znode_t
*zp
= ITOZ(ip
);
336 error
= -zfs_map(ip
, vma
->vm_pgoff
, (caddr_t
*)vma
->vm_start
,
337 (size_t)(vma
->vm_end
- vma
->vm_start
), vma
->vm_flags
);
341 error
= generic_file_mmap(filp
, vma
);
345 mutex_enter(&zp
->z_lock
);
347 mutex_exit(&zp
->z_lock
);
353 * Populate a page with data for the Linux page cache. This function is
354 * only used to support mmap(2). There will be an identical copy of the
355 * data in the ARC which is kept up to date via .write() and .writepage().
357 * Current this function relies on zpl_read_common() and the O_DIRECT
358 * flag to read in a page. This works but the more correct way is to
359 * update zfs_fillpage() to be Linux friendly and use that interface.
362 zpl_readpage(struct file
*filp
, struct page
*pp
)
368 ASSERT(PageLocked(pp
));
369 ip
= pp
->mapping
->host
;
372 error
= -zfs_getpage(ip
, pl
, 1);
376 ClearPageUptodate(pp
);
380 flush_dcache_page(pp
);
388 * Populate a set of pages with data for the Linux page cache. This
389 * function will only be called for read ahead and never for demand
390 * paging. For simplicity, the code relies on read_cache_pages() to
391 * correctly lock each page for IO and call zpl_readpage().
394 zpl_readpages(struct file
*filp
, struct address_space
*mapping
,
395 struct list_head
*pages
, unsigned nr_pages
)
397 return (read_cache_pages(mapping
, pages
,
398 (filler_t
*)zpl_readpage
, filp
));
402 zpl_putpage(struct page
*pp
, struct writeback_control
*wbc
, void *data
)
404 struct address_space
*mapping
= data
;
406 ASSERT(PageLocked(pp
));
407 ASSERT(!PageWriteback(pp
));
408 ASSERT(!(current
->flags
& PF_NOFS
));
411 * Annotate this call path with a flag that indicates that it is
412 * unsafe to use KM_SLEEP during memory allocations due to the
413 * potential for a deadlock. KM_PUSHPAGE should be used instead.
415 current
->flags
|= PF_NOFS
;
416 (void) zfs_putpage(mapping
->host
, pp
, wbc
);
417 current
->flags
&= ~PF_NOFS
;
423 zpl_writepages(struct address_space
*mapping
, struct writeback_control
*wbc
)
425 znode_t
*zp
= ITOZ(mapping
->host
);
426 zfs_sb_t
*zsb
= ITOZSB(mapping
->host
);
427 enum writeback_sync_modes sync_mode
;
431 if (zsb
->z_os
->os_sync
== ZFS_SYNC_ALWAYS
)
432 wbc
->sync_mode
= WB_SYNC_ALL
;
434 sync_mode
= wbc
->sync_mode
;
437 * We don't want to run write_cache_pages() in SYNC mode here, because
438 * that would make putpage() wait for a single page to be committed to
439 * disk every single time, resulting in atrocious performance. Instead
440 * we run it once in non-SYNC mode so that the ZIL gets all the data,
441 * and then we commit it all in one go.
443 wbc
->sync_mode
= WB_SYNC_NONE
;
444 result
= write_cache_pages(mapping
, wbc
, zpl_putpage
, mapping
);
445 if (sync_mode
!= wbc
->sync_mode
) {
448 zil_commit(zsb
->z_log
, zp
->z_id
);
452 * We need to call write_cache_pages() again (we can't just
453 * return after the commit) because the previous call in
454 * non-SYNC mode does not guarantee that we got all the dirty
455 * pages (see the implementation of write_cache_pages() for
456 * details). That being said, this is a no-op in most cases.
458 wbc
->sync_mode
= sync_mode
;
459 result
= write_cache_pages(mapping
, wbc
, zpl_putpage
, mapping
);
465 * Write out dirty pages to the ARC, this function is only required to
466 * support mmap(2). Mapped pages may be dirtied by memory operations
467 * which never call .write(). These dirty pages are kept in sync with
468 * the ARC buffers via this hook.
471 zpl_writepage(struct page
*pp
, struct writeback_control
*wbc
)
473 if (ITOZSB(pp
->mapping
->host
)->z_os
->os_sync
== ZFS_SYNC_ALWAYS
)
474 wbc
->sync_mode
= WB_SYNC_ALL
;
476 return (zpl_putpage(pp
, wbc
, pp
->mapping
));
480 * The only flag combination which matches the behavior of zfs_space()
481 * is FALLOC_FL_PUNCH_HOLE. This flag was introduced in the 2.6.38 kernel.
484 zpl_fallocate_common(struct inode
*ip
, int mode
, loff_t offset
, loff_t len
)
487 int error
= -EOPNOTSUPP
;
489 if (mode
& FALLOC_FL_KEEP_SIZE
)
490 return (-EOPNOTSUPP
);
494 #ifdef FALLOC_FL_PUNCH_HOLE
495 if (mode
& FALLOC_FL_PUNCH_HOLE
) {
504 error
= -zfs_space(ip
, F_FREESP
, &bf
, FWRITE
, offset
, cr
);
506 #endif /* FALLOC_FL_PUNCH_HOLE */
510 ASSERT3S(error
, <=, 0);
514 #ifdef HAVE_FILE_FALLOCATE
516 zpl_fallocate(struct file
*filp
, int mode
, loff_t offset
, loff_t len
)
518 return zpl_fallocate_common(filp
->f_path
.dentry
->d_inode
,
521 #endif /* HAVE_FILE_FALLOCATE */
524 zpl_ioctl(struct file
*filp
, unsigned int cmd
, unsigned long arg
)
527 case ZFS_IOC_GETFLAGS
:
528 case ZFS_IOC_SETFLAGS
:
529 return (-EOPNOTSUPP
);
537 zpl_compat_ioctl(struct file
*filp
, unsigned int cmd
, unsigned long arg
)
539 return (zpl_ioctl(filp
, cmd
, arg
));
541 #endif /* CONFIG_COMPAT */
544 const struct address_space_operations zpl_address_space_operations
= {
545 .readpages
= zpl_readpages
,
546 .readpage
= zpl_readpage
,
547 .writepage
= zpl_writepage
,
548 .writepages
= zpl_writepages
,
551 const struct file_operations zpl_file_operations
= {
553 .release
= zpl_release
,
554 .llseek
= zpl_llseek
,
559 #ifdef HAVE_FILE_FALLOCATE
560 .fallocate
= zpl_fallocate
,
561 #endif /* HAVE_FILE_FALLOCATE */
562 .unlocked_ioctl
= zpl_ioctl
,
564 .compat_ioctl
= zpl_compat_ioctl
,
568 const struct file_operations zpl_dir_file_operations
= {
569 .llseek
= generic_file_llseek
,
570 .read
= generic_read_dir
,
571 #ifdef HAVE_VFS_ITERATE
572 .iterate
= zpl_iterate
,
574 .readdir
= zpl_readdir
,
577 .unlocked_ioctl
= zpl_ioctl
,
579 .compat_ioctl
= zpl_compat_ioctl
,