* 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/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
*/
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
*/
req->pages[0] = page;
get_page(page);
- ret = afs_vnode_fetch_data(vnode, key, req);
+ ret = afs_fetch_data(vnode, key, req);
afs_put_read(req);
if (ret < 0) {
if (ret == -ENOENT) {
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;
- unsigned from = pos & (PAGE_SIZE - 1);
- unsigned to = from + len;
+ struct key *key = afs_file_key(file);
+ unsigned long priv;
+ unsigned f, from = pos & (PAGE_SIZE - 1);
+ unsigned t, to = from + len;
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);
+ /* We want to store information about how much of a page is altered in
+ * page->private.
+ */
+ BUILD_BUG_ON(PAGE_SIZE > 32768 && sizeof(page->private) < 8);
page = grab_cache_page_write_begin(mapping, index, flags);
- if (!page) {
- kfree(candidate);
+ if (!page)
return -ENOMEM;
- }
if (!PageUptodate(page) && len != PAGE_SIZE) {
ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page);
if (ret < 0) {
unlock_page(page);
put_page(page);
- kfree(candidate);
_leave(" = %d [prep]", ret);
return ret;
}
*pagep = 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;
+ /* See if this page is already partially written in a way that we can
+ * merge the new write with.
+ */
+ t = f = 0;
+ if (PagePrivate(page)) {
+ priv = page_private(page);
+ f = priv & AFS_PRIV_MAX;
+ t = priv >> AFS_PRIV_SHIFT;
+ ASSERTCMP(f, <=, t);
}
- 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;
- }
+ if (f != t) {
+ if (to < f || from > t)
+ goto flush_conflicting_write;
+ if (from < f)
+ f = from;
+ if (to > t)
+ t = to;
+ } else {
+ f = from;
+ t = to;
}
- 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);
+ priv = (unsigned long)t << AFS_PRIV_SHIFT;
+ priv |= f;
+ trace_afs_page_dirty(vnode, tracepoint_string("begin"),
+ page->index, priv);
SetPagePrivate(page);
- set_page_private(page, (unsigned long) wb);
- kfree(candidate);
- _leave(" = 0 [app]");
+ set_page_private(page, priv);
+ _leave(" = 0");
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:
+ /* The previous write and this write aren't adjacent or overlapping, so
+ * flush the page out.
+ */
+flush_conflicting_write:
_debug("flush conflict");
- if (wb->state == AFS_WBACK_PENDING)
- wb->state = AFS_WBACK_CONFLICTING;
- spin_unlock(&vnode->writeback_lock);
- if (clear_page_dirty_for_io(page)) {
- ret = afs_write_back_from_locked_page(wb, page);
- if (ret < 0) {
- afs_put_writeback(candidate);
- _leave(" = %d", ret);
- return ret;
- }
+ ret = write_one_page(page);
+ if (ret < 0) {
+ _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);
+ ret = lock_page_killable(page);
+ if (ret < 0) {
+ _leave(" = %d", ret);
+ return ret;
+ }
goto try_again;
}
struct page *page, void *fsdata)
{
struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
- struct key *key = file->private_data;
+ struct key *key = afs_file_key(file);
loff_t i_size, maybe_i_size;
int ret;
i_size = i_size_read(&vnode->vfs_inode);
if (maybe_i_size > i_size) {
- spin_lock(&vnode->writeback_lock);
+ spin_lock(&vnode->wb_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);
+ spin_unlock(&vnode->wb_lock);
}
if (!PageUptodate(page)) {
/*
* kill all the pages in the given range
*/
-static void afs_kill_pages(struct afs_vnode *vnode, bool error,
+static void afs_kill_pages(struct address_space *mapping,
pgoff_t first, pgoff_t last)
{
+ struct afs_vnode *vnode = AFS_FS_I(mapping->host);
struct pagevec pv;
unsigned count, loop;
_enter("{%x:%u},%lx-%lx",
vnode->fid.vid, vnode->fid.vnode, first, last);
- pagevec_init(&pv, 0);
+ pagevec_init(&pv);
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);
+ pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
ASSERTCMP(pv.nr, ==, count);
for (loop = 0; loop < count; loop++) {
struct page *page = pv.pages[loop];
ClearPageUptodate(page);
- if (error)
- SetPageError(page);
- if (PageWriteback(page))
- end_page_writeback(page);
+ SetPageError(page);
+ end_page_writeback(page);
+ if (page->index >= first)
+ first = page->index + 1;
+ lock_page(page);
+ generic_error_remove_page(mapping, page);
+ }
+
+ __pagevec_release(&pv);
+ } while (first <= last);
+
+ _leave("");
+}
+
+/*
+ * Redirty all the pages in a given range.
+ */
+static void afs_redirty_pages(struct writeback_control *wbc,
+ struct address_space *mapping,
+ pgoff_t first, pgoff_t last)
+{
+ struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+ struct pagevec pv;
+ unsigned count, loop;
+
+ _enter("{%x:%u},%lx-%lx",
+ vnode->fid.vid, vnode->fid.vnode, first, last);
+
+ pagevec_init(&pv);
+
+ do {
+ _debug("redirty %lx-%lx", first, last);
+
+ count = last - first + 1;
+ if (count > PAGEVEC_SIZE)
+ count = PAGEVEC_SIZE;
+ pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
+ ASSERTCMP(pv.nr, ==, count);
+
+ for (loop = 0; loop < count; loop++) {
+ struct page *page = pv.pages[loop];
+
+ redirty_page_for_writepage(wbc, page);
+ end_page_writeback(page);
if (page->index >= first)
first = page->index + 1;
}
__pagevec_release(&pv);
- } while (first < last);
+ } while (first <= last);
_leave("");
}
/*
- * synchronously write back the locked page and any subsequent non-locked dirty
- * pages also covered by the same writeback record
+ * write to a file
*/
-static int afs_write_back_from_locked_page(struct afs_writeback *wb,
- struct page *primary_page)
+static int afs_store_data(struct address_space *mapping,
+ pgoff_t first, pgoff_t last,
+ unsigned offset, unsigned to)
{
+ struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+ struct afs_fs_cursor fc;
+ struct afs_wb_key *wbk = NULL;
+ struct list_head *p;
+ int ret = -ENOKEY, ret2;
+
+ _enter("%s{%x:%u.%u},%lx,%lx,%x,%x",
+ vnode->volume->name,
+ vnode->fid.vid,
+ vnode->fid.vnode,
+ vnode->fid.unique,
+ first, last, offset, to);
+
+ spin_lock(&vnode->wb_lock);
+ p = vnode->wb_keys.next;
+
+ /* Iterate through the list looking for a valid key to use. */
+try_next_key:
+ while (p != &vnode->wb_keys) {
+ wbk = list_entry(p, struct afs_wb_key, vnode_link);
+ _debug("wbk %u", key_serial(wbk->key));
+ ret2 = key_validate(wbk->key);
+ if (ret2 == 0)
+ goto found_key;
+ if (ret == -ENOKEY)
+ ret = ret2;
+ p = p->next;
+ }
+
+ spin_unlock(&vnode->wb_lock);
+ afs_put_wb_key(wbk);
+ _leave(" = %d [no keys]", ret);
+ return ret;
+
+found_key:
+ refcount_inc(&wbk->usage);
+ spin_unlock(&vnode->wb_lock);
+
+ _debug("USE WB KEY %u", key_serial(wbk->key));
+
+ ret = -ERESTARTSYS;
+ if (afs_begin_vnode_operation(&fc, vnode, wbk->key)) {
+ while (afs_select_fileserver(&fc)) {
+ fc.cb_break = vnode->cb_break + vnode->cb_s_break;
+ afs_fs_store_data(&fc, mapping, first, last, offset, to);
+ }
+
+ afs_check_for_remote_deletion(&fc, fc.vnode);
+ afs_vnode_commit_status(&fc, vnode, fc.cb_break);
+ ret = afs_end_vnode_operation(&fc);
+ }
+
+ switch (ret) {
+ case -EACCES:
+ case -EPERM:
+ case -ENOKEY:
+ case -EKEYEXPIRED:
+ case -EKEYREJECTED:
+ case -EKEYREVOKED:
+ _debug("next");
+ spin_lock(&vnode->wb_lock);
+ p = wbk->vnode_link.next;
+ afs_put_wb_key(wbk);
+ goto try_next_key;
+ }
+
+ afs_put_wb_key(wbk);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Synchronously write back the locked page and any subsequent non-locked dirty
+ * pages.
+ */
+static int afs_write_back_from_locked_page(struct address_space *mapping,
+ struct writeback_control *wbc,
+ struct page *primary_page,
+ pgoff_t final_page)
+{
+ struct afs_vnode *vnode = AFS_FS_I(mapping->host);
struct page *pages[8], *page;
- unsigned long count;
- unsigned n, offset, to;
+ unsigned long count, priv;
+ unsigned n, offset, to, f, t;
pgoff_t start, first, last;
int loop, ret;
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 */
+ /* Find all consecutive lockable dirty pages that have contiguous
+ * written regions, 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)
+ priv = page_private(primary_page);
+ offset = priv & AFS_PRIV_MAX;
+ to = priv >> AFS_PRIV_SHIFT;
+ trace_afs_page_dirty(vnode, tracepoint_string("store"),
+ primary_page->index, priv);
+
+ WARN_ON(offset == to);
+ if (offset == to)
+ trace_afs_page_dirty(vnode, tracepoint_string("WARN"),
+ primary_page->index, priv);
+
+ if (start >= final_page || to < PAGE_SIZE)
goto no_more;
+
start++;
do {
_debug("more %lx [%lx]", start, count);
- n = wb->last - start + 1;
+ n = final_page - 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);
+ n = find_get_pages_contig(mapping, start, ARRAY_SIZE(pages), pages);
_debug("fgpc %u", n);
if (n == 0)
goto no_more;
}
for (loop = 0; loop < n; loop++) {
+ if (to != PAGE_SIZE)
+ break;
page = pages[loop];
- if (page->index > wb->last)
+ if (page->index > final_page)
break;
if (!trylock_page(page))
break;
- if (!PageDirty(page) ||
- page_private(page) != (unsigned long) wb) {
+ if (!PageDirty(page) || PageWriteback(page)) {
unlock_page(page);
break;
}
+
+ priv = page_private(page);
+ f = priv & AFS_PRIV_MAX;
+ t = priv >> AFS_PRIV_SHIFT;
+ if (f != 0) {
+ unlock_page(page);
+ break;
+ }
+ to = t;
+
+ trace_afs_page_dirty(vnode, tracepoint_string("store+"),
+ page->index, priv);
+
if (!clear_page_dirty_for_io(page))
BUG();
if (test_set_page_writeback(page))
}
start += loop;
- } while (start <= wb->last && count < 65536);
+ } while (start <= final_page && 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 */
+ /* We now have a contiguous set of dirty pages, each with writeback
+ * set; the first page is still locked at this point, but all the rest
+ * have been unlocked.
+ */
+ unlock_page(primary_page);
+
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 = afs_store_data(mapping, first, last, offset, to);
+ switch (ret) {
+ case 0:
ret = count;
+ break;
+
+ default:
+ pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret);
+ /* Fall through */
+ case -EACCES:
+ case -EPERM:
+ case -ENOKEY:
+ case -EKEYEXPIRED:
+ case -EKEYREJECTED:
+ case -EKEYREVOKED:
+ afs_redirty_pages(wbc, mapping, first, last);
+ mapping_set_error(mapping, ret);
+ break;
+
+ case -EDQUOT:
+ case -ENOSPC:
+ afs_redirty_pages(wbc, mapping, first, last);
+ mapping_set_error(mapping, -ENOSPC);
+ break;
+
+ case -EROFS:
+ case -EIO:
+ case -EREMOTEIO:
+ case -EFBIG:
+ case -ENOENT:
+ case -ENOMEDIUM:
+ case -ENXIO:
+ afs_kill_pages(mapping, first, last);
+ mapping_set_error(mapping, ret);
+ break;
}
_leave(" = %d", ret);
*/
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);
+ ret = afs_write_back_from_locked_page(page->mapping, wbc, page,
+ wbc->range_end >> PAGE_SHIFT);
if (ret < 0) {
_leave(" = %d", ret);
return 0;
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);
+ n = find_get_pages_range_tag(mapping, &index, end,
+ PAGECACHE_TAG_DIRTY, 1, &page);
if (!n)
break;
_debug("wback %lx", page->index);
- if (page->index > end) {
- *_next = index;
- 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);
+ ret = lock_page_killable(page);
+ if (ret < 0) {
+ put_page(page);
+ _leave(" = %d", ret);
+ return ret;
+ }
if (page->mapping != mapping || !PageDirty(page)) {
unlock_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);
-
if (!clear_page_dirty_for_io(page))
BUG();
- ret = afs_write_back_from_locked_page(wb, page);
- unlock_page(page);
+ ret = afs_write_back_from_locked_page(mapping, wbc, page, end);
put_page(page);
if (ret < 0) {
_leave(" = %d", ret);
*/
void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call)
{
- struct afs_writeback *wb = call->wb;
struct pagevec pv;
+ unsigned long priv;
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);
+ pagevec_init(&pv);
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);
+ pv.nr = find_get_pages_contig(vnode->vfs_inode.i_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;
+ priv = page_private(pv.pages[loop]);
+ trace_afs_page_dirty(vnode, tracepoint_string("clear"),
+ pv.pages[loop]->index, priv);
+ set_page_private(pv.pages[loop], 0);
+ end_page_writeback(pv.pages[loop]);
}
- spin_unlock(&vnode->writeback_lock);
first += count;
- if (free_wb) {
- afs_free_writeback(wb);
- wb = NULL;
- }
-
__pagevec_release(&pv);
} while (first <= last);
+ afs_prune_wb_keys(vnode);
_leave("");
}
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
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 = file_write_and_wait_range(file, 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;
+ return file_write_and_wait_range(file, start, end);
}
/*
* 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)
+int afs_page_mkwrite(struct vm_fault *vmf)
{
- struct afs_vnode *vnode = AFS_FS_I(vma->vm_file->f_mapping->host);
+ struct file *file = vmf->vma->vm_file;
+ struct inode *inode = file_inode(file);
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ unsigned long priv;
_enter("{{%x:%u}},{%lx}",
- vnode->fid.vid, vnode->fid.vnode, page->index);
+ vnode->fid.vid, vnode->fid.vnode, vmf->page->index);
+
+ sb_start_pagefault(inode->i_sb);
- /* wait for the page to be written to the cache before we allow it to
- * be modified */
+ /* Wait for the page to be written to the cache before we allow it to
+ * be modified. We then assume the entire page will need writing back.
+ */
#ifdef CONFIG_AFS_FSCACHE
- fscache_wait_on_page_write(vnode->cache, page);
+ fscache_wait_on_page_write(vnode->cache, vmf->page);
#endif
- _leave(" = 0");
- return 0;
+ if (PageWriteback(vmf->page) &&
+ wait_on_page_bit_killable(vmf->page, PG_writeback) < 0)
+ return VM_FAULT_RETRY;
+
+ if (lock_page_killable(vmf->page) < 0)
+ return VM_FAULT_RETRY;
+
+ /* We mustn't change page->private until writeback is complete as that
+ * details the portion of the page we need to write back and we might
+ * need to redirty the page if there's a problem.
+ */
+ wait_on_page_writeback(vmf->page);
+
+ priv = (unsigned long)PAGE_SIZE << AFS_PRIV_SHIFT; /* To */
+ priv |= 0; /* From */
+ trace_afs_page_dirty(vnode, tracepoint_string("mkwrite"),
+ vmf->page->index, priv);
+ SetPagePrivate(vmf->page);
+ set_page_private(vmf->page, priv);
+
+ sb_end_pagefault(inode->i_sb);
+ return VM_FAULT_LOCKED;
+}
+
+/*
+ * Prune the keys cached for writeback. The caller must hold vnode->wb_lock.
+ */
+void afs_prune_wb_keys(struct afs_vnode *vnode)
+{
+ LIST_HEAD(graveyard);
+ struct afs_wb_key *wbk, *tmp;
+
+ /* Discard unused keys */
+ spin_lock(&vnode->wb_lock);
+
+ if (!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) &&
+ !mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_DIRTY)) {
+ list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) {
+ if (refcount_read(&wbk->usage) == 1)
+ list_move(&wbk->vnode_link, &graveyard);
+ }
+ }
+
+ spin_unlock(&vnode->wb_lock);
+
+ while (!list_empty(&graveyard)) {
+ wbk = list_entry(graveyard.next, struct afs_wb_key, vnode_link);
+ list_del(&wbk->vnode_link);
+ afs_put_wb_key(wbk);
+ }
+}
+
+/*
+ * Clean up a page during invalidation.
+ */
+int afs_launder_page(struct page *page)
+{
+ struct address_space *mapping = page->mapping;
+ struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+ unsigned long priv;
+ unsigned int f, t;
+ int ret = 0;
+
+ _enter("{%lx}", page->index);
+
+ priv = page_private(page);
+ if (clear_page_dirty_for_io(page)) {
+ f = 0;
+ t = PAGE_SIZE;
+ if (PagePrivate(page)) {
+ f = priv & AFS_PRIV_MAX;
+ t = priv >> AFS_PRIV_SHIFT;
+ }
+
+ trace_afs_page_dirty(vnode, tracepoint_string("launder"),
+ page->index, priv);
+ ret = afs_store_data(mapping, page->index, page->index, t, f);
+ }
+
+ trace_afs_page_dirty(vnode, tracepoint_string("laundered"),
+ page->index, priv);
+ set_page_private(page, 0);
+ ClearPagePrivate(page);
+
+#ifdef CONFIG_AFS_FSCACHE
+ if (PageFsCache(page)) {
+ fscache_wait_on_page_write(vnode->cache, page);
+ fscache_uncache_page(vnode->cache, page);
+ }
+#endif
+ return ret;
}
git.samba.org / sfrench / cifs-2.6.git / blobdiff