afs: Get rid of the afs_writeback record
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>
diff --git a/fs/afs/file.c b/fs/afs/file.c
index e33b34f..c3a7bc1 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -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);
@@ -63,6 +62,50 @@ const struct address_space_operations afs_fs_aops = {
};
/*
+ * 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
*/
int afs_open(struct inode *inode, struct file *file)
@@ -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;
}
@@ -517,16 +569,6 @@ static int afs_readpages(struct file *file, struct address_space *mapping,
}
/*
- * 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
* the entire page)
@@ -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);
}
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 10e5ead..b90ef39 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -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;
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index da2ba7a..3415eb7 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -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);
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index facf5b9..688562a 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -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 */
@@ -139,10 +138,20 @@ struct afs_call_type {
};
/*
+ * 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)
@@ -168,32 +177,6 @@ struct afs_read {
};
/*
- * 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
diff --git a/fs/afs/super.c b/fs/afs/super.c
index af1e769..875b5eb 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -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);
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 1cdd0e3..4c13137 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -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
@@ -29,58 +40,6 @@ int afs_set_page_dirty(struct page *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,
@@ -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 @@ static int afs_write_back_from_locked_page(struct afs_writeback *wb,
*/
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("");
}
@@ -711,28 +715,6 @@ ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from)
}
/*
- * 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.
@@ -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;
+}
diff --git a/mm/filemap.c b/mm/filemap.c
index 594d73f..5bcc87a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -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
