linux/fs/afs/write.c

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18 KiB
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/* handling of writes to regular files and writing back to the server
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/backing-dev.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/writeback.h>
#include <linux/pagevec.h>
#include "internal.h"
static int afs_write_back_from_locked_page(struct afs_writeback *wb,
struct page *page);
/*
* mark a page as having been made dirty and thus needing writeback
*/
int afs_set_page_dirty(struct page *page)
{
_enter("");
return __set_page_dirty_nobuffers(page);
}
/*
* unlink a writeback record because its usage has reached zero
* - must be called with the wb->vnode->writeback_lock held
*/
static void afs_unlink_writeback(struct afs_writeback *wb)
{
struct afs_writeback *front;
struct afs_vnode *vnode = wb->vnode;
list_del_init(&wb->link);
if (!list_empty(&vnode->writebacks)) {
/* if an fsync rises to the front of the queue then wake it
* up */
front = list_entry(vnode->writebacks.next,
struct afs_writeback, link);
if (front->state == AFS_WBACK_SYNCING) {
_debug("wake up sync");
front->state = AFS_WBACK_COMPLETE;
wake_up(&front->waitq);
}
}
}
/*
* free a writeback record
*/
static void afs_free_writeback(struct afs_writeback *wb)
{
_enter("");
key_put(wb->key);
kfree(wb);
}
/*
* dispose of a reference to a writeback record
*/
void afs_put_writeback(struct afs_writeback *wb)
{
struct afs_vnode *vnode = wb->vnode;
_enter("{%d}", wb->usage);
spin_lock(&vnode->writeback_lock);
if (--wb->usage == 0)
afs_unlink_writeback(wb);
else
wb = NULL;
spin_unlock(&vnode->writeback_lock);
if (wb)
afs_free_writeback(wb);
}
/*
* partly or wholly fill a page that's under preparation for writing
*/
static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
loff_t pos, struct page *page)
{
struct afs_read *req;
loff_t i_size;
int ret;
_enter(",,%llu", (unsigned long long)pos);
req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
GFP_KERNEL);
if (!req)
return -ENOMEM;
atomic_set(&req->usage, 1);
req->pos = pos;
req->nr_pages = 1;
req->pages[0] = page;
i_size = i_size_read(&vnode->vfs_inode);
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 12:29:47 +00:00
if (pos + PAGE_SIZE > i_size)
req->len = i_size - pos;
else
req->len = PAGE_SIZE;
ret = afs_vnode_fetch_data(vnode, key, req);
afs_put_read(req);
if (ret < 0) {
if (ret == -ENOENT) {
_debug("got NOENT from server"
" - marking file deleted and stale");
set_bit(AFS_VNODE_DELETED, &vnode->flags);
ret = -ESTALE;
}
}
_leave(" = %d", ret);
return ret;
}
/*
* prepare to perform part of a write to a page
*/
int afs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
struct afs_writeback *candidate, *wb;
struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
struct page *page;
struct key *key = file->private_data;
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 12:29:47 +00:00
unsigned from = pos & (PAGE_SIZE - 1);
unsigned to = from + len;
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 12:29:47 +00:00
pgoff_t index = pos >> PAGE_SHIFT;
int ret;
_enter("{%x:%u},{%lx},%u,%u",
vnode->fid.vid, vnode->fid.vnode, index, from, to);
candidate = kzalloc(sizeof(*candidate), GFP_KERNEL);
if (!candidate)
return -ENOMEM;
candidate->vnode = vnode;
candidate->first = candidate->last = index;
candidate->offset_first = from;
candidate->to_last = to;
INIT_LIST_HEAD(&candidate->link);
candidate->usage = 1;
candidate->state = AFS_WBACK_PENDING;
init_waitqueue_head(&candidate->waitq);
fs: symlink write_begin allocation context fix With the write_begin/write_end aops, page_symlink was broken because it could no longer pass a GFP_NOFS type mask into the point where the allocations happened. They are done in write_begin, which would always assume that the filesystem can be entered from reclaim. This bug could cause filesystem deadlocks. The funny thing with having a gfp_t mask there is that it doesn't really allow the caller to arbitrarily tinker with the context in which it can be called. It couldn't ever be GFP_ATOMIC, for example, because it needs to take the page lock. The only thing any callers care about is __GFP_FS anyway, so turn that into a single flag. Add a new flag for write_begin, AOP_FLAG_NOFS. Filesystems can now act on this flag in their write_begin function. Change __grab_cache_page to accept a nofs argument as well, to honour that flag (while we're there, change the name to grab_cache_page_write_begin which is more instructive and does away with random leading underscores). This is really a more flexible way to go in the end anyway -- if a filesystem happens to want any extra allocations aside from the pagecache ones in ints write_begin function, it may now use GFP_KERNEL (rather than GFP_NOFS) for common case allocations (eg. ocfs2_alloc_write_ctxt, for a random example). [kosaki.motohiro@jp.fujitsu.com: fix ubifs] [kosaki.motohiro@jp.fujitsu.com: fix fuse] Signed-off-by: Nick Piggin <npiggin@suse.de> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: <stable@kernel.org> [2.6.28.x] Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ Cleaned up the calling convention: just pass in the AOP flags untouched to the grab_cache_page_write_begin() function. That just simplifies everybody, and may even allow future expansion of the logic. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-04 20:00:53 +00:00
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page) {
kfree(candidate);
return -ENOMEM;
}
*pagep = page;
/* page won't leak in error case: it eventually gets cleaned off LRU */
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 12:29:47 +00:00
if (!PageUptodate(page) && len != PAGE_SIZE) {
ret = afs_fill_page(vnode, key, index << PAGE_SHIFT, page);
if (ret < 0) {
kfree(candidate);
_leave(" = %d [prep]", ret);
return ret;
}
SetPageUptodate(page);
}
try_again:
spin_lock(&vnode->writeback_lock);
/* see if this page is already pending a writeback under a suitable key
* - if so we can just join onto that one */
wb = (struct afs_writeback *) page_private(page);
if (wb) {
if (wb->key == key && wb->state == AFS_WBACK_PENDING)
goto subsume_in_current_wb;
goto flush_conflicting_wb;
}
if (index > 0) {
/* see if we can find an already pending writeback that we can
* append this page to */
list_for_each_entry(wb, &vnode->writebacks, link) {
if (wb->last == index - 1 && wb->key == key &&
wb->state == AFS_WBACK_PENDING)
goto append_to_previous_wb;
}
}
list_add_tail(&candidate->link, &vnode->writebacks);
candidate->key = key_get(key);
spin_unlock(&vnode->writeback_lock);
SetPagePrivate(page);
set_page_private(page, (unsigned long) candidate);
_leave(" = 0 [new]");
return 0;
subsume_in_current_wb:
_debug("subsume");
ASSERTRANGE(wb->first, <=, index, <=, wb->last);
if (index == wb->first && from < wb->offset_first)
wb->offset_first = from;
if (index == wb->last && to > wb->to_last)
wb->to_last = to;
spin_unlock(&vnode->writeback_lock);
kfree(candidate);
_leave(" = 0 [sub]");
return 0;
append_to_previous_wb:
_debug("append into %lx-%lx", wb->first, wb->last);
wb->usage++;
wb->last++;
wb->to_last = to;
spin_unlock(&vnode->writeback_lock);
SetPagePrivate(page);
set_page_private(page, (unsigned long) wb);
kfree(candidate);
_leave(" = 0 [app]");
return 0;
/* the page is currently bound to another context, so if it's dirty we
* need to flush it before we can use the new context */
flush_conflicting_wb:
_debug("flush conflict");
if (wb->state == AFS_WBACK_PENDING)
wb->state = AFS_WBACK_CONFLICTING;
spin_unlock(&vnode->writeback_lock);
if (PageDirty(page)) {
ret = afs_write_back_from_locked_page(wb, page);
if (ret < 0) {
afs_put_writeback(candidate);
_leave(" = %d", ret);
return ret;
}
}
/* the page holds a ref on the writeback record */
afs_put_writeback(wb);
set_page_private(page, 0);
ClearPagePrivate(page);
goto try_again;
}
/*
* finalise part of a write to a page
*/
int afs_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
loff_t i_size, maybe_i_size;
_enter("{%x:%u},{%lx}",
vnode->fid.vid, vnode->fid.vnode, page->index);
maybe_i_size = pos + copied;
i_size = i_size_read(&vnode->vfs_inode);
if (maybe_i_size > i_size) {
spin_lock(&vnode->writeback_lock);
i_size = i_size_read(&vnode->vfs_inode);
if (maybe_i_size > i_size)
i_size_write(&vnode->vfs_inode, maybe_i_size);
spin_unlock(&vnode->writeback_lock);
}
set_page_dirty(page);
if (PageDirty(page))
_debug("dirtied");
unlock_page(page);
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 12:29:47 +00:00
put_page(page);
return copied;
}
/*
* kill all the pages in the given range
*/
static void afs_kill_pages(struct afs_vnode *vnode, bool error,
pgoff_t first, pgoff_t last)
{
struct pagevec pv;
unsigned count, loop;
_enter("{%x:%u},%lx-%lx",
vnode->fid.vid, vnode->fid.vnode, first, last);
pagevec_init(&pv, 0);
do {
_debug("kill %lx-%lx", first, last);
count = last - first + 1;
if (count > PAGEVEC_SIZE)
count = PAGEVEC_SIZE;
pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping,
first, count, pv.pages);
ASSERTCMP(pv.nr, ==, count);
for (loop = 0; loop < count; loop++) {
ClearPageUptodate(pv.pages[loop]);
if (error)
SetPageError(pv.pages[loop]);
end_page_writeback(pv.pages[loop]);
}
__pagevec_release(&pv);
} while (first < last);
_leave("");
}
/*
* synchronously write back the locked page and any subsequent non-locked dirty
* pages also covered by the same writeback record
*/
static int afs_write_back_from_locked_page(struct afs_writeback *wb,
struct page *primary_page)
{
struct page *pages[8], *page;
unsigned long count;
unsigned n, offset, to;
pgoff_t start, first, last;
int loop, ret;
_enter(",%lx", primary_page->index);
count = 1;
if (!clear_page_dirty_for_io(primary_page))
BUG();
if (test_set_page_writeback(primary_page))
BUG();
/* find all consecutive lockable dirty pages, stopping when we find a
* page that is not immediately lockable, is not dirty or is missing,
* or we reach the end of the range */
start = primary_page->index;
if (start >= wb->last)
goto no_more;
start++;
do {
_debug("more %lx [%lx]", start, count);
n = wb->last - start + 1;
if (n > ARRAY_SIZE(pages))
n = ARRAY_SIZE(pages);
n = find_get_pages_contig(wb->vnode->vfs_inode.i_mapping,
start, n, pages);
_debug("fgpc %u", n);
if (n == 0)
goto no_more;
if (pages[0]->index != start) {
do {
put_page(pages[--n]);
} while (n > 0);
goto no_more;
}
for (loop = 0; loop < n; loop++) {
page = pages[loop];
if (page->index > wb->last)
break;
if (!trylock_page(page))
break;
if (!PageDirty(page) ||
page_private(page) != (unsigned long) wb) {
unlock_page(page);
break;
}
if (!clear_page_dirty_for_io(page))
BUG();
if (test_set_page_writeback(page))
BUG();
unlock_page(page);
put_page(page);
}
count += loop;
if (loop < n) {
for (; loop < n; loop++)
put_page(pages[loop]);
goto no_more;
}
start += loop;
} while (start <= wb->last && count < 65536);
no_more:
/* we now have a contiguous set of dirty pages, each with writeback set
* and the dirty mark cleared; the first page is locked and must remain
* so, all the rest are unlocked */
first = primary_page->index;
last = first + count - 1;
offset = (first == wb->first) ? wb->offset_first : 0;
to = (last == wb->last) ? wb->to_last : PAGE_SIZE;
_debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to);
ret = afs_vnode_store_data(wb, first, last, offset, to);
if (ret < 0) {
switch (ret) {
case -EDQUOT:
case -ENOSPC:
mapping_set_error(wb->vnode->vfs_inode.i_mapping, -ENOSPC);
break;
case -EROFS:
case -EIO:
case -EREMOTEIO:
case -EFBIG:
case -ENOENT:
case -ENOMEDIUM:
case -ENXIO:
afs_kill_pages(wb->vnode, true, first, last);
mapping_set_error(wb->vnode->vfs_inode.i_mapping, -EIO);
break;
case -EACCES:
case -EPERM:
case -ENOKEY:
case -EKEYEXPIRED:
case -EKEYREJECTED:
case -EKEYREVOKED:
afs_kill_pages(wb->vnode, false, first, last);
break;
default:
break;
}
} else {
ret = count;
}
_leave(" = %d", ret);
return ret;
}
/*
* write a page back to the server
* - the caller locked the page for us
*/
int afs_writepage(struct page *page, struct writeback_control *wbc)
{
struct afs_writeback *wb;
int ret;
_enter("{%lx},", page->index);
wb = (struct afs_writeback *) page_private(page);
ASSERT(wb != NULL);
ret = afs_write_back_from_locked_page(wb, page);
unlock_page(page);
if (ret < 0) {
_leave(" = %d", ret);
return 0;
}
wbc->nr_to_write -= ret;
_leave(" = 0");
return 0;
}
/*
* write a region of pages back to the server
*/
static int afs_writepages_region(struct address_space *mapping,
struct writeback_control *wbc,
pgoff_t index, pgoff_t end, pgoff_t *_next)
{
struct afs_writeback *wb;
struct page *page;
int ret, n;
_enter(",,%lx,%lx,", index, end);
do {
n = find_get_pages_tag(mapping, &index, PAGECACHE_TAG_DIRTY,
1, &page);
if (!n)
break;
_debug("wback %lx", page->index);
if (page->index > end) {
*_next = index;
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 12:29:47 +00:00
put_page(page);
_leave(" = 0 [%lx]", *_next);
return 0;
}
/* at this point we hold neither mapping->tree_lock nor lock on
* the page itself: the page may be truncated or invalidated
* (changing page->mapping to NULL), or even swizzled back from
* swapper_space to tmpfs file mapping
*/
lock_page(page);
if (page->mapping != mapping) {
unlock_page(page);
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 12:29:47 +00:00
put_page(page);
continue;
}
if (wbc->sync_mode != WB_SYNC_NONE)
wait_on_page_writeback(page);
if (PageWriteback(page) || !PageDirty(page)) {
unlock_page(page);
put_page(page);
continue;
}
wb = (struct afs_writeback *) page_private(page);
ASSERT(wb != NULL);
spin_lock(&wb->vnode->writeback_lock);
wb->state = AFS_WBACK_WRITING;
spin_unlock(&wb->vnode->writeback_lock);
ret = afs_write_back_from_locked_page(wb, page);
unlock_page(page);
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 12:29:47 +00:00
put_page(page);
if (ret < 0) {
_leave(" = %d", ret);
return ret;
}
wbc->nr_to_write -= ret;
cond_resched();
} while (index < end && wbc->nr_to_write > 0);
*_next = index;
_leave(" = 0 [%lx]", *_next);
return 0;
}
/*
* write some of the pending data back to the server
*/
int afs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
pgoff_t start, end, next;
int ret;
_enter("");
if (wbc->range_cyclic) {
start = mapping->writeback_index;
end = -1;
ret = afs_writepages_region(mapping, wbc, start, end, &next);
if (start > 0 && wbc->nr_to_write > 0 && ret == 0)
ret = afs_writepages_region(mapping, wbc, 0, start,
&next);
mapping->writeback_index = next;
} else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 12:29:47 +00:00
end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT);
ret = afs_writepages_region(mapping, wbc, 0, end, &next);
if (wbc->nr_to_write > 0)
mapping->writeback_index = next;
} else {
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 12:29:47 +00:00
start = wbc->range_start >> PAGE_SHIFT;
end = wbc->range_end >> PAGE_SHIFT;
ret = afs_writepages_region(mapping, wbc, start, end, &next);
}
_leave(" = %d", ret);
return ret;
}
/*
* completion of write to server
*/
void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call)
{
struct afs_writeback *wb = call->wb;
struct pagevec pv;
unsigned count, loop;
pgoff_t first = call->first, last = call->last;
bool free_wb;
_enter("{%x:%u},{%lx-%lx}",
vnode->fid.vid, vnode->fid.vnode, first, last);
ASSERT(wb != NULL);
pagevec_init(&pv, 0);
do {
_debug("done %lx-%lx", first, last);
count = last - first + 1;
if (count > PAGEVEC_SIZE)
count = PAGEVEC_SIZE;
pv.nr = find_get_pages_contig(call->mapping, first, count,
pv.pages);
ASSERTCMP(pv.nr, ==, count);
spin_lock(&vnode->writeback_lock);
for (loop = 0; loop < count; loop++) {
struct page *page = pv.pages[loop];
end_page_writeback(page);
if (page_private(page) == (unsigned long) wb) {
set_page_private(page, 0);
ClearPagePrivate(page);
wb->usage--;
}
}
free_wb = false;
if (wb->usage == 0) {
afs_unlink_writeback(wb);
free_wb = true;
}
spin_unlock(&vnode->writeback_lock);
first += count;
if (free_wb) {
afs_free_writeback(wb);
wb = NULL;
}
__pagevec_release(&pv);
} while (first <= last);
_leave("");
}
/*
* write to an AFS file
*/
ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from)
{
struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp));
ssize_t result;
size_t count = iov_iter_count(from);
_enter("{%x.%u},{%zu},",
vnode->fid.vid, vnode->fid.vnode, count);
if (IS_SWAPFILE(&vnode->vfs_inode)) {
printk(KERN_INFO
"AFS: Attempt to write to active swap file!\n");
return -EBUSY;
}
if (!count)
return 0;
result = generic_file_write_iter(iocb, from);
_leave(" = %zd", result);
return result;
}
/*
* flush the vnode to the fileserver
*/
int afs_writeback_all(struct afs_vnode *vnode)
{
struct address_space *mapping = vnode->vfs_inode.i_mapping;
struct writeback_control wbc = {
.sync_mode = WB_SYNC_ALL,
.nr_to_write = LONG_MAX,
.range_cyclic = 1,
};
int ret;
_enter("");
ret = mapping->a_ops->writepages(mapping, &wbc);
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
_leave(" = %d", ret);
return ret;
}
/*
* flush any dirty pages for this process, and check for write errors.
* - the return status from this call provides a reliable indication of
* whether any write errors occurred for this process.
*/
int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
struct inode *inode = file_inode(file);
struct afs_writeback *wb, *xwb;
struct afs_vnode *vnode = AFS_FS_I(inode);
int ret;
_enter("{%x:%u},{n=%pD},%d",
vnode->fid.vid, vnode->fid.vnode, file,
datasync);
ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
if (ret)
return ret;
inode_lock(inode);
/* use a writeback record as a marker in the queue - when this reaches
* the front of the queue, all the outstanding writes are either
* completed or rejected */
wb = kzalloc(sizeof(*wb), GFP_KERNEL);
if (!wb) {
ret = -ENOMEM;
goto out;
}
wb->vnode = vnode;
wb->first = 0;
wb->last = -1;
wb->offset_first = 0;
wb->to_last = PAGE_SIZE;
wb->usage = 1;
wb->state = AFS_WBACK_SYNCING;
init_waitqueue_head(&wb->waitq);
spin_lock(&vnode->writeback_lock);
list_for_each_entry(xwb, &vnode->writebacks, link) {
if (xwb->state == AFS_WBACK_PENDING)
xwb->state = AFS_WBACK_CONFLICTING;
}
list_add_tail(&wb->link, &vnode->writebacks);
spin_unlock(&vnode->writeback_lock);
/* push all the outstanding writebacks to the server */
ret = afs_writeback_all(vnode);
if (ret < 0) {
afs_put_writeback(wb);
_leave(" = %d [wb]", ret);
goto out;
}
/* wait for the preceding writes to actually complete */
ret = wait_event_interruptible(wb->waitq,
wb->state == AFS_WBACK_COMPLETE ||
vnode->writebacks.next == &wb->link);
afs_put_writeback(wb);
_leave(" = %d", ret);
out:
inode_unlock(inode);
return ret;
}
/*
* notification that a previously read-only page is about to become writable
* - if it returns an error, the caller will deliver a bus error signal
*/
int afs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
{
struct afs_vnode *vnode = AFS_FS_I(vma->vm_file->f_mapping->host);
_enter("{{%x:%u}},{%lx}",
vnode->fid.vid, vnode->fid.vnode, page->index);
/* wait for the page to be written to the cache before we allow it to
* be modified */
#ifdef CONFIG_AFS_FSCACHE
fscache_wait_on_page_write(vnode->cache, page);
#endif
_leave(" = 0");
return 0;
}