int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
unsigned int flags)
{
- if (flags & FAULT_FLAG_ALLOW_RETRY) {
+ if (fault_flag_allow_retry_first(flags)) {
/*
* CAUTION! In this case, mmap_sem is not released
* even though return 0.
return page;
}
-EXPORT_SYMBOL(find_get_entry);
/**
* find_lock_entry - locate, pin and lock a page cache entry
EXPORT_SYMBOL(find_lock_entry);
/**
- * pagecache_get_page - find and get a page reference
- * @mapping: the address_space to search
- * @offset: the page index
- * @fgp_flags: PCG flags
- * @gfp_mask: gfp mask to use for the page cache data page allocation
- *
- * Looks up the page cache slot at @mapping & @offset.
+ * pagecache_get_page - Find and get a reference to a page.
+ * @mapping: The address_space to search.
+ * @index: The page index.
+ * @fgp_flags: %FGP flags modify how the page is returned.
+ * @gfp_mask: Memory allocation flags to use if %FGP_CREAT is specified.
*
- * PCG flags modify how the page is returned.
+ * Looks up the page cache entry at @mapping & @index.
*
- * @fgp_flags can be:
+ * @fgp_flags can be zero or more of these flags:
*
- * - FGP_ACCESSED: the page will be marked accessed
- * - FGP_LOCK: Page is return locked
- * - FGP_CREAT: If page is not present then a new page is allocated using
- * @gfp_mask and added to the page cache and the VM's LRU
- * list. The page is returned locked and with an increased
- * refcount.
- * - FGP_FOR_MMAP: Similar to FGP_CREAT, only we want to allow the caller to do
- * its own locking dance if the page is already in cache, or unlock the page
- * before returning if we had to add the page to pagecache.
+ * * %FGP_ACCESSED - The page will be marked accessed.
+ * * %FGP_LOCK - The page is returned locked.
+ * * %FGP_CREAT - If no page is present then a new page is allocated using
+ * @gfp_mask and added to the page cache and the VM's LRU list.
+ * The page is returned locked and with an increased refcount.
+ * * %FGP_FOR_MMAP - The caller wants to do its own locking dance if the
+ * page is already in cache. If the page was allocated, unlock it before
+ * returning so the caller can do the same dance.
*
- * If FGP_LOCK or FGP_CREAT are specified then the function may sleep even
- * if the GFP flags specified for FGP_CREAT are atomic.
+ * If %FGP_LOCK or %FGP_CREAT are specified then the function may sleep even
+ * if the %GFP flags specified for %FGP_CREAT are atomic.
*
* If there is a page cache page, it is returned with an increased refcount.
*
- * Return: the found page or %NULL otherwise.
+ * Return: The found page or %NULL otherwise.
*/
-struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
- int fgp_flags, gfp_t gfp_mask)
+struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
+ int fgp_flags, gfp_t gfp_mask)
{
struct page *page;
repeat:
- page = find_get_entry(mapping, offset);
+ page = find_get_entry(mapping, index);
if (xa_is_value(page))
page = NULL;
if (!page)
put_page(page);
goto repeat;
}
- VM_BUG_ON_PAGE(page->index != offset, page);
+ VM_BUG_ON_PAGE(page->index != index, page);
}
if (fgp_flags & FGP_ACCESSED)
if (fgp_flags & FGP_ACCESSED)
__SetPageReferenced(page);
- err = add_to_page_cache_lru(page, mapping, offset, gfp_mask);
+ err = add_to_page_cache_lru(page, mapping, index, gfp_mask);
if (unlikely(err)) {
put_page(page);
page = NULL;
* Any shadow entries of evicted pages, or swap entries from
* shmem/tmpfs, are included in the returned array.
*
+ * If it finds a Transparent Huge Page, head or tail, find_get_entries()
+ * stops at that page: the caller is likely to have a better way to handle
+ * the compound page as a whole, and then skip its extent, than repeatedly
+ * calling find_get_entries() to return all its tails.
+ *
* Return: the number of pages and shadow entries which were found.
*/
unsigned find_get_entries(struct address_space *mapping,
/* Has the page moved or been split? */
if (unlikely(page != xas_reload(&xas)))
goto put_page;
- page = find_subpage(page, xas.xa_index);
+ /*
+ * Terminate early on finding a THP, to allow the caller to
+ * handle it all at once; but continue if this is hugetlbfs.
+ */
+ if (PageTransHuge(page) && !PageHuge(page)) {
+ page = find_subpage(page, xas.xa_index);
+ nr_entries = ret + 1;
+ }
export:
indices[ret] = xas.xa_index;
entries[ret] = page;
*
* It is going insane. Fix it by quickly scaling down the readahead size.
*/
-static void shrink_readahead_size_eio(struct file *filp,
- struct file_ra_state *ra)
+static void shrink_readahead_size_eio(struct file_ra_state *ra)
{
ra->ra_pages /= 4;
}
goto find_page;
}
unlock_page(page);
- shrink_readahead_size_eio(filp, ra);
+ shrink_readahead_size_eio(ra);
error = -EIO;
goto readpage_error;
}
pgoff_t offset = vmf->pgoff;
/* If we don't want any read-ahead, don't bother */
- if (vmf->vma->vm_flags & VM_RAND_READ)
+ if (vmf->vma->vm_flags & VM_RAND_READ || !ra->ra_pages)
return fpin;
if (ra->mmap_miss > 0)
ra->mmap_miss--;
if (!page) {
if (fpin)
goto out_retry;
- return vmf_error(-ENOMEM);
+ return VM_FAULT_OOM;
}
}
goto retry_find;
/* Things didn't work out. Return zero to tell the mm layer so. */
- shrink_readahead_size_eio(file, ra);
+ shrink_readahead_size_eio(ra);
return VM_FAULT_SIGBUS;
out_retry:
unlock_page(page);
goto out;
}
+
+ /*
+ * A previous I/O error may have been due to temporary
+ * failures.
+ * Clear page error before actual read, PG_error will be
+ * set again if read page fails.
+ */
+ ClearPageError(page);
goto filler;
out:
projects / linux-2.6-microblaze.git / blobdiff