struct page *find_or_create_page(struct address_space *mapping,
pgoff_t index, gfp_t gfp_mask)
{
- struct page *page, *cached_page = NULL;
+ struct page *page;
int err;
repeat:
page = find_lock_page(mapping, index);
if (!page) {
- if (!cached_page) {
- cached_page =
- __page_cache_alloc(gfp_mask);
- if (!cached_page)
- return NULL;
+ page = __page_cache_alloc(gfp_mask);
+ if (!page)
+ return NULL;
+ err = add_to_page_cache_lru(page, mapping, index, gfp_mask);
+ if (unlikely(err)) {
+ page_cache_release(page);
+ page = NULL;
+ if (err == -EEXIST)
+ goto repeat;
}
- err = add_to_page_cache_lru(cached_page, mapping,
- index, gfp_mask);
- if (!err) {
- page = cached_page;
- cached_page = NULL;
- } else if (err == -EEXIST)
- goto repeat;
}
- if (cached_page)
- page_cache_release(cached_page);
return page;
}
EXPORT_SYMBOL(find_or_create_page);
pgoff_t prev_index;
unsigned long offset; /* offset into pagecache page */
unsigned int prev_offset;
- struct page *cached_page;
int error;
- cached_page = NULL;
index = *ppos >> PAGE_CACHE_SHIFT;
prev_index = ra->prev_pos >> PAGE_CACHE_SHIFT;
prev_offset = ra->prev_pos & (PAGE_CACHE_SIZE-1);
* Ok, it wasn't cached, so we need to create a new
* page..
*/
- if (!cached_page) {
- cached_page = page_cache_alloc_cold(mapping);
- if (!cached_page) {
- desc->error = -ENOMEM;
- goto out;
- }
+ page = page_cache_alloc_cold(mapping);
+ if (!page) {
+ desc->error = -ENOMEM;
+ goto out;
}
- error = add_to_page_cache_lru(cached_page, mapping,
+ error = add_to_page_cache_lru(page, mapping,
index, GFP_KERNEL);
if (error) {
+ page_cache_release(page);
if (error == -EEXIST)
goto find_page;
desc->error = error;
goto out;
}
- page = cached_page;
- cached_page = NULL;
goto readpage;
}
ra->prev_pos |= prev_offset;
*ppos = ((loff_t)index << PAGE_CACHE_SHIFT) + offset;
- if (cached_page)
- page_cache_release(cached_page);
if (filp)
file_accessed(filp);
}
int (*filler)(void *,struct page*),
void *data)
{
- struct page *page, *cached_page = NULL;
+ struct page *page;
int err;
repeat:
page = find_get_page(mapping, index);
if (!page) {
- if (!cached_page) {
- cached_page = page_cache_alloc_cold(mapping);
- if (!cached_page)
- return ERR_PTR(-ENOMEM);
- }
- err = add_to_page_cache_lru(cached_page, mapping,
- index, GFP_KERNEL);
- if (err == -EEXIST)
- goto repeat;
- if (err < 0) {
+ page = page_cache_alloc_cold(mapping);
+ if (!page)
+ return ERR_PTR(-ENOMEM);
+ err = add_to_page_cache_lru(page, mapping, index, GFP_KERNEL);
+ if (unlikely(err)) {
+ page_cache_release(page);
+ if (err == -EEXIST)
+ goto repeat;
/* Presumably ENOMEM for radix tree node */
- page_cache_release(cached_page);
return ERR_PTR(err);
}
- page = cached_page;
- cached_page = NULL;
err = filler(data, page);
if (err < 0) {
page_cache_release(page);
page = ERR_PTR(err);
}
}
- if (cached_page)
- page_cache_release(cached_page);
return page;
}
}
EXPORT_SYMBOL(read_cache_page);
-/*
- * If the page was newly created, increment its refcount and add it to the
- * caller's lru-buffering pagevec. This function is specifically for
- * generic_file_write().
- */
-static inline struct page *
-__grab_cache_page(struct address_space *mapping, unsigned long index,
- struct page **cached_page, struct pagevec *lru_pvec)
-{
- int err;
- struct page *page;
-repeat:
- page = find_lock_page(mapping, index);
- if (!page) {
- if (!*cached_page) {
- *cached_page = page_cache_alloc(mapping);
- if (!*cached_page)
- return NULL;
- }
- err = add_to_page_cache(*cached_page, mapping,
- index, GFP_KERNEL);
- if (err == -EEXIST)
- goto repeat;
- if (err == 0) {
- page = *cached_page;
- page_cache_get(page);
- if (!pagevec_add(lru_pvec, page))
- __pagevec_lru_add(lru_pvec);
- *cached_page = NULL;
- }
- }
- return page;
-}
-
/*
* The logic we want is
*
}
EXPORT_SYMBOL(generic_file_direct_write);
+/*
+ * Find or create a page at the given pagecache position. Return the locked
+ * page. This function is specifically for buffered writes.
+ */
+static struct page *__grab_cache_page(struct address_space *mapping,
+ pgoff_t index)
+{
+ int status;
+ struct page *page;
+repeat:
+ page = find_lock_page(mapping, index);
+ if (likely(page))
+ return page;
+
+ page = page_cache_alloc(mapping);
+ if (!page)
+ return NULL;
+ status = add_to_page_cache_lru(page, mapping, index, GFP_KERNEL);
+ if (unlikely(status)) {
+ page_cache_release(page);
+ if (status == -EEXIST)
+ goto repeat;
+ return NULL;
+ }
+ return page;
+}
+
ssize_t
generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos, loff_t *ppos,
const struct address_space_operations *a_ops = mapping->a_ops;
struct inode *inode = mapping->host;
long status = 0;
- struct page *page;
- struct page *cached_page = NULL;
- struct pagevec lru_pvec;
const struct iovec *cur_iov = iov; /* current iovec */
size_t iov_offset = 0; /* offset in the current iovec */
char __user *buf;
- pagevec_init(&lru_pvec, 0);
-
/*
* handle partial DIO write. Adjust cur_iov if needed.
*/
}
do {
+ struct page *page;
pgoff_t index; /* Pagecache index for current page */
unsigned long offset; /* Offset into pagecache page */
unsigned long maxlen; /* Bytes remaining in current iovec */
fault_in_pages_readable(buf, maxlen);
#endif
- page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec);
+
+ page = __grab_cache_page(mapping, index);
if (!page) {
status = -ENOMEM;
break;
} while (count);
*ppos = pos;
- if (cached_page)
- page_cache_release(cached_page);
-
/*
* For now, when the user asks for O_SYNC, we'll actually give O_DSYNC
*/
if (unlikely(file->f_flags & O_DIRECT) && written)
status = filemap_write_and_wait(mapping);
- pagevec_lru_add(&lru_pvec);
return written ? written : status;
}
EXPORT_SYMBOL(generic_file_buffered_write);
Code Review / linux-2.6.git / blobdiff