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afs: Get rid of the afs_writeback record

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Get rid of the afs_writeback record that kAFS is using to match keys with
writes made by that key.

Instead, keep a list of keys that have a file open for writing and/or
sync'ing and iterate through those.

Signed-off-by: David Howells <dhowells@redhat.com>
This commit is contained in:
David Howells 2017-11-02 15:27:52 +00:00
parent 215804a992
commit 4343d00872
7 changed files with 412 additions and 395 deletions
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83
fs/afs/file.c
View file

@ -23,7 +23,6 @@ static int afs_readpage(struct file *file, struct page *page);
static void afs_invalidatepage(struct page *page, unsigned int offset,
unsigned int length);
static int afs_releasepage(struct page *page, gfp_t gfp_flags);
static int afs_launder_page(struct page *page);
static int afs_readpages(struct file *filp, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages);
@ -62,6 +61,50 @@ const struct address_space_operations afs_fs_aops = {
.writepages = afs_writepages,
};
/*
* Discard a pin on a writeback key.
*/
void afs_put_wb_key(struct afs_wb_key *wbk)
{
if (refcount_dec_and_test(&wbk->usage)) {
key_put(wbk->key);
kfree(wbk);
}
}
/*
* Cache key for writeback.
*/
int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af)
{
struct afs_wb_key *wbk, *p;
wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL);
if (!wbk)
return -ENOMEM;
refcount_set(&wbk->usage, 2);
wbk->key = af->key;
spin_lock(&vnode->wb_lock);
list_for_each_entry(p, &vnode->wb_keys, vnode_link) {
if (p->key == wbk->key)
goto found;
}
key_get(wbk->key);
list_add_tail(&wbk->vnode_link, &vnode->wb_keys);
spin_unlock(&vnode->wb_lock);
af->wb = wbk;
return 0;
found:
refcount_inc(&p->usage);
spin_unlock(&vnode->wb_lock);
af->wb = p;
kfree(wbk);
return 0;
}
/*
* open an AFS file or directory and attach a key to it
*/
@ -85,12 +128,18 @@ int afs_open(struct inode *inode, struct file *file)
ret = -ENOMEM;
goto error_key;
}
af->key = key;
ret = afs_validate(vnode, key);
if (ret < 0)
goto error_af;
af->key = key;
if (file->f_mode & FMODE_WRITE) {
ret = afs_cache_wb_key(vnode, af);
if (ret < 0)
goto error_af;
}
file->private_data = af;
_leave(" = 0");
return 0;
@ -115,8 +164,11 @@ int afs_release(struct inode *inode, struct file *file)
_enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode);
file->private_data = NULL;
if (af->wb)
afs_put_wb_key(af->wb);
key_put(af->key);
kfree(af);
afs_prune_wb_keys(vnode);
_leave(" = 0");
return 0;
}
@ -516,16 +568,6 @@ static int afs_readpages(struct file *file, struct address_space *mapping,
return ret;
}
/*
* write back a dirty page
*/
static int afs_launder_page(struct page *page)
{
_enter("{%lu}", page->index);
return 0;
}
/*
* invalidate part or all of a page
* - release a page and clean up its private data if offset is 0 (indicating
@ -534,8 +576,6 @@ static int afs_launder_page(struct page *page)
static void afs_invalidatepage(struct page *page, unsigned int offset,
unsigned int length)
{
struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
_enter("{%lu},%u,%u", page->index, offset, length);
BUG_ON(!PageLocked(page));
@ -551,13 +591,8 @@ static void afs_invalidatepage(struct page *page, unsigned int offset,
#endif
if (PagePrivate(page)) {
if (wb && !PageWriteback(page)) {
set_page_private(page, 0);
afs_put_writeback(wb);
}
if (!page_private(page))
ClearPagePrivate(page);
set_page_private(page, 0);
ClearPagePrivate(page);
}
}
@ -570,7 +605,6 @@ static void afs_invalidatepage(struct page *page, unsigned int offset,
*/
static int afs_releasepage(struct page *page, gfp_t gfp_flags)
{
struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
_enter("{{%x:%u}[%lu],%lx},%x",
@ -587,10 +621,7 @@ static int afs_releasepage(struct page *page, gfp_t gfp_flags)
#endif
if (PagePrivate(page)) {
if (wb) {
set_page_private(page, 0);
afs_put_writeback(wb);
}
set_page_private(page, 0);
ClearPagePrivate(page);
}

24
fs/afs/fsclient.c
View file

@ -1119,18 +1119,18 @@ static const struct afs_call_type afs_RXFSStoreData64 = {
* store a set of pages to a very large file
*/
static int afs_fs_store_data64(struct afs_fs_cursor *fc,
struct afs_writeback *wb,
struct address_space *mapping,
pgoff_t first, pgoff_t last,
unsigned offset, unsigned to,
loff_t size, loff_t pos, loff_t i_size)
{
struct afs_vnode *vnode = wb->vnode;
struct afs_vnode *vnode = fc->vnode;
struct afs_call *call;
struct afs_net *net = afs_v2net(vnode);
__be32 *bp;
_enter(",%x,{%x:%u},,",
key_serial(wb->key), vnode->fid.vid, vnode->fid.vnode);
key_serial(fc->key), vnode->fid.vid, vnode->fid.vnode);
call = afs_alloc_flat_call(net, &afs_RXFSStoreData64,
(4 + 6 + 3 * 2) * 4,
@ -1138,10 +1138,9 @@ static int afs_fs_store_data64(struct afs_fs_cursor *fc,
if (!call)
return -ENOMEM;
call->wb = wb;
call->key = wb->key;
call->key = fc->key;
call->mapping = mapping;
call->reply[0] = vnode;
call->mapping = vnode->vfs_inode.i_mapping;
call->first = first;
call->last = last;
call->first_offset = offset;
@ -1177,18 +1176,18 @@ static int afs_fs_store_data64(struct afs_fs_cursor *fc,
/*
* store a set of pages
*/
int afs_fs_store_data(struct afs_fs_cursor *fc, struct afs_writeback *wb,
int afs_fs_store_data(struct afs_fs_cursor *fc, struct address_space *mapping,
pgoff_t first, pgoff_t last,
unsigned offset, unsigned to)
{
struct afs_vnode *vnode = wb->vnode;
struct afs_vnode *vnode = fc->vnode;
struct afs_call *call;
struct afs_net *net = afs_v2net(vnode);
loff_t size, pos, i_size;
__be32 *bp;
_enter(",%x,{%x:%u},,",
key_serial(wb->key), vnode->fid.vid, vnode->fid.vnode);
key_serial(fc->key), vnode->fid.vid, vnode->fid.vnode);
size = (loff_t)to - (loff_t)offset;
if (first != last)
@ -1205,7 +1204,7 @@ int afs_fs_store_data(struct afs_fs_cursor *fc, struct afs_writeback *wb,
(unsigned long long) i_size);
if (pos >> 32 || i_size >> 32 || size >> 32 || (pos + size) >> 32)
return afs_fs_store_data64(fc, wb, first, last, offset, to,
return afs_fs_store_data64(fc, mapping, first, last, offset, to,
size, pos, i_size);
call = afs_alloc_flat_call(net, &afs_RXFSStoreData,
@ -1214,10 +1213,9 @@ int afs_fs_store_data(struct afs_fs_cursor *fc, struct afs_writeback *wb,
if (!call)
return -ENOMEM;
call->wb = wb;
call->key = wb->key;
call->key = fc->key;
call->mapping = mapping;
call->reply[0] = vnode;
call->mapping = vnode->vfs_inode.i_mapping;
call->first = first;
call->last = last;
call->first_offset = offset;

11
fs/afs/inode.c
View file

@ -482,7 +482,12 @@ void afs_evict_inode(struct inode *inode)
vnode->cb_interest = NULL;
}
ASSERT(list_empty(&vnode->writebacks));
while (!list_empty(&vnode->wb_keys)) {
struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
struct afs_wb_key, vnode_link);
list_del(&wbk->vnode_link);
afs_put_wb_key(wbk);
}
#ifdef CONFIG_AFS_FSCACHE
fscache_relinquish_cookie(vnode->cache, 0);
@ -514,10 +519,8 @@ int afs_setattr(struct dentry *dentry, struct iattr *attr)
}
/* flush any dirty data outstanding on a regular file */
if (S_ISREG(vnode->vfs_inode.i_mode)) {
if (S_ISREG(vnode->vfs_inode.i_mode))
filemap_write_and_wait(vnode->vfs_inode.i_mapping);
afs_writeback_all(vnode);
}
if (attr->ia_valid & ATTR_FILE) {
key = afs_file_key(attr->ia_file);

51
fs/afs/internal.h
View file

@ -89,8 +89,7 @@ struct afs_call {
struct afs_server *cm_server; /* Server affected by incoming CM call */
struct afs_cb_interest *cbi; /* Callback interest for server used */
void *request; /* request data (first part) */
struct address_space *mapping; /* page set */
struct afs_writeback *wb; /* writeback being performed */
struct address_space *mapping; /* Pages being written from */
void *buffer; /* reply receive buffer */
void *reply[4]; /* Where to put the reply */
pgoff_t first; /* first page in mapping to deal with */
@ -138,11 +137,21 @@ struct afs_call_type {
void (*work)(struct work_struct *work);
};
/*
* Key available for writeback on a file.
*/
struct afs_wb_key {
refcount_t usage;
struct key *key;
struct list_head vnode_link; /* Link in vnode->wb_keys */
};
/*
* AFS open file information record. Pointed to by file->private_data.
*/
struct afs_file {
struct key *key; /* The key this file was opened with */
struct afs_wb_key *wb; /* Writeback key record for this file */
};
static inline struct key *afs_file_key(struct file *file)
@ -167,32 +176,6 @@ struct afs_read {
struct page *pages[];
};
/*
* record of an outstanding writeback on a vnode
*/
struct afs_writeback {
struct list_head link; /* link in vnode->writebacks */
struct work_struct writer; /* work item to perform the writeback */
struct afs_vnode *vnode; /* vnode to which this write applies */
struct key *key; /* owner of this write */
wait_queue_head_t waitq; /* completion and ready wait queue */
pgoff_t first; /* first page in batch */
pgoff_t point; /* last page in current store op */
pgoff_t last; /* last page in batch (inclusive) */
unsigned offset_first; /* offset into first page of start of write */
unsigned to_last; /* offset into last page of end of write */
int num_conflicts; /* count of conflicting writes in list */
int usage;
bool conflicts; /* T if has dependent conflicts */
enum {
AFS_WBACK_SYNCING, /* synchronisation being performed */
AFS_WBACK_PENDING, /* write pending */
AFS_WBACK_CONFLICTING, /* conflicting writes posted */
AFS_WBACK_WRITING, /* writing back */
AFS_WBACK_COMPLETE /* the writeback record has been unlinked */
} state __attribute__((packed));
};
/*
* AFS superblock private data
* - there's one superblock per volume
@ -460,7 +443,7 @@ struct afs_vnode {
struct afs_permits *permit_cache; /* cache of permits so far obtained */
struct mutex io_lock; /* Lock for serialising I/O on this mutex */
struct mutex validate_lock; /* lock for validating this vnode */
spinlock_t writeback_lock; /* lock for writebacks */
spinlock_t wb_lock; /* lock for wb_keys */
spinlock_t lock; /* waitqueue/flags lock */
unsigned long flags;
#define AFS_VNODE_CB_PROMISED 0 /* Set if vnode has a callback promise */
@ -476,7 +459,7 @@ struct afs_vnode {
#define AFS_VNODE_AUTOCELL 10 /* set if Vnode is an auto mount point */
#define AFS_VNODE_PSEUDODIR 11 /* set if Vnode is a pseudo directory */
struct list_head writebacks; /* alterations in pagecache that need writing */
struct list_head wb_keys; /* List of keys available for writeback */
struct list_head pending_locks; /* locks waiting to be granted */
struct list_head granted_locks; /* locks granted on this file */
struct delayed_work lock_work; /* work to be done in locking */
@ -648,6 +631,8 @@ extern const struct address_space_operations afs_fs_aops;
extern const struct inode_operations afs_file_inode_operations;
extern const struct file_operations afs_file_operations;
extern int afs_cache_wb_key(struct afs_vnode *, struct afs_file *);
extern void afs_put_wb_key(struct afs_wb_key *);
extern int afs_open(struct inode *, struct file *);
extern int afs_release(struct inode *, struct file *);
extern int afs_fetch_data(struct afs_vnode *, struct key *, struct afs_read *);
@ -678,7 +663,7 @@ extern int afs_fs_symlink(struct afs_fs_cursor *, const char *, const char *,
struct afs_fid *, struct afs_file_status *);
extern int afs_fs_rename(struct afs_fs_cursor *, const char *,
struct afs_vnode *, const char *);
extern int afs_fs_store_data(struct afs_fs_cursor *, struct afs_writeback *,
extern int afs_fs_store_data(struct afs_fs_cursor *, struct address_space *,
pgoff_t, pgoff_t, unsigned, unsigned);
extern int afs_fs_setattr(struct afs_fs_cursor *, struct iattr *);
extern int afs_fs_get_volume_status(struct afs_fs_cursor *, struct afs_volume_status *);
@ -889,7 +874,6 @@ extern int afs_check_volume_status(struct afs_volume *, struct key *);
* write.c
*/
extern int afs_set_page_dirty(struct page *);
extern void afs_put_writeback(struct afs_writeback *);
extern int afs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata);
@ -900,9 +884,10 @@ extern int afs_writepage(struct page *, struct writeback_control *);
extern int afs_writepages(struct address_space *, struct writeback_control *);
extern void afs_pages_written_back(struct afs_vnode *, struct afs_call *);
extern ssize_t afs_file_write(struct kiocb *, struct iov_iter *);
extern int afs_writeback_all(struct afs_vnode *);
extern int afs_flush(struct file *, fl_owner_t);
extern int afs_fsync(struct file *, loff_t, loff_t, int);
extern void afs_prune_wb_keys(struct afs_vnode *);
extern int afs_launder_page(struct page *);
/*
* xattr.c

4
fs/afs/super.c
View file

@ -546,9 +546,9 @@ static void afs_i_init_once(void *_vnode)
inode_init_once(&vnode->vfs_inode);
mutex_init(&vnode->io_lock);
mutex_init(&vnode->validate_lock);
spin_lock_init(&vnode->writeback_lock);
spin_lock_init(&vnode->wb_lock);
spin_lock_init(&vnode->lock);
INIT_LIST_HEAD(&vnode->writebacks);
INIT_LIST_HEAD(&vnode->wb_keys);
INIT_LIST_HEAD(&vnode->pending_locks);
INIT_LIST_HEAD(&vnode->granted_locks);
INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);

633
fs/afs/write.c
View file

@ -8,6 +8,7 @@
* 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>
@ -16,8 +17,18 @@
#include <linux/pagevec.h>
#include "internal.h"
static int afs_write_back_from_locked_page(struct afs_writeback *wb,
struct page *page);
/*
* We use page->private to hold the amount of the page that we've written to,
* splitting the field into two parts. However, we need to represent a range
* 0...PAGE_SIZE inclusive, so we can't support 64K pages on a 32-bit system.
*/
#if PAGE_SIZE > 32768
#define AFS_PRIV_MAX 0xffffffff
#define AFS_PRIV_SHIFT 32
#else
#define AFS_PRIV_MAX 0xffff
#define AFS_PRIV_SHIFT 16
#endif
/*
* mark a page as having been made dirty and thus needing writeback
@ -28,58 +39,6 @@ int afs_set_page_dirty(struct page *page)
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
*/
@ -125,42 +84,32 @@ 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 = afs_file_key(file);
unsigned from = pos & (PAGE_SIZE - 1);
unsigned to = from + len;
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;
}
@ -171,79 +120,52 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
*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);
priv = (unsigned long)t << AFS_PRIV_SHIFT;
priv |= f;
SetPagePrivate(page);
set_page_private(page, (unsigned long) candidate);
_leave(" = 0 [new]");
set_page_private(page, priv);
_leave(" = 0");
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:
/* 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;
}
@ -266,11 +188,11 @@ int afs_write_end(struct file *file, struct address_space *mapping,
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)) {
@ -299,9 +221,10 @@ int afs_write_end(struct file *file, struct address_space *mapping,
/*
* 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;
@ -316,23 +239,62 @@ static void afs_kill_pages(struct afs_vnode *vnode, bool error,
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, 0);
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("");
}
@ -340,26 +302,55 @@ static void afs_kill_pages(struct afs_vnode *vnode, bool error,
/*
* write to a file
*/
static int afs_store_data(struct afs_writeback *wb, pgoff_t first, pgoff_t last,
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_vnode *vnode = wb->vnode;
int ret;
struct afs_wb_key *wbk = NULL;
struct list_head *p;
int ret = -ENOKEY, ret2;
_enter("%s{%x:%u.%u},%x,%lx,%lx,%x,%x",
_enter("%s{%x:%u.%u},%lx,%lx,%x,%x",
vnode->volume->name,
vnode->fid.vid,
vnode->fid.vnode,
vnode->fid.unique,
key_serial(wb->key),
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, wb->key)) {
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, wb, first, last, offset, to);
afs_fs_store_data(&fc, mapping, first, last, offset, to);
}
afs_check_for_remote_deletion(&fc, fc.vnode);
@ -367,20 +358,37 @@ static int afs_store_data(struct afs_writeback *wb, pgoff_t first, pgoff_t last,
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 also covered by the same writeback record
* Synchronously write back the locked page and any subsequent non-locked dirty
* pages.
*/
static int afs_write_back_from_locked_page(struct afs_writeback *wb,
struct page *primary_page)
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 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;
@ -390,20 +398,28 @@ static int afs_write_back_from_locked_page(struct afs_writeback *wb,
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;
WARN_ON(offset == to);
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;
@ -415,16 +431,27 @@ static int afs_write_back_from_locked_page(struct afs_writeback *wb,
}
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;
if (!clear_page_dirty_for_io(page))
BUG();
if (test_set_page_writeback(page))
@ -440,50 +467,55 @@ static int afs_write_back_from_locked_page(struct afs_writeback *wb,
}
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_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);
@ -496,16 +528,12 @@ no_more:
*/
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;
@ -524,7 +552,6 @@ 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;
@ -550,7 +577,12 @@ static int afs_writepages_region(struct address_space *mapping,
* (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);
@ -566,17 +598,9 @@ static int afs_writepages_region(struct address_space *mapping,
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);
@ -632,17 +656,13 @@ int afs_writepages(struct address_space *mapping,
*/
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 {
@ -651,35 +671,19 @@ void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call)
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--;
}
set_page_private(pv.pages[loop], 0);
end_page_writeback(pv.pages[loop]);
}
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);
afs_prune_wb_keys(vnode);
_leave("");
}
@ -710,28 +714,6 @@ ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from)
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
@ -740,61 +722,13 @@ int afs_writeback_all(struct afs_vnode *vnode)
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);
}
/*
@ -831,3 +765,68 @@ int afs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
_leave(" = 0");
return 0;
}
/*
* 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;
}
ret = afs_store_data(mapping, page->index, page->index, t, f);
}
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;
}

1
mm/filemap.c
View file

@ -1041,6 +1041,7 @@ int wait_on_page_bit_killable(struct page *page, int bit_nr)
wait_queue_head_t *q = page_waitqueue(page);
return wait_on_page_bit_common(q, page, bit_nr, TASK_KILLABLE, false);
}
EXPORT_SYMBOL(wait_on_page_bit_killable);
/**
* add_page_wait_queue - Add an arbitrary waiter to a page's wait queue