#include <asm/mman.h>
-static ssize_t
-generic_file_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
- loff_t offset, unsigned long nr_segs);
/*
* Shared mappings implemented 30.11.1994. It's not fully working yet,
/*
* Remove a page from the page cache and free it. Caller has to make
* sure the page is locked and that nobody else uses it - or that usage
- * is safe. The caller must hold a write_lock on the mapping's tree_lock.
+ * is safe. The caller must hold the mapping's tree_lock.
*/
void __remove_from_page_cache(struct page *page)
{
struct address_space *mapping = page->mapping;
- mem_cgroup_uncharge_page(page);
+ mem_cgroup_uncharge_cache_page(page);
radix_tree_delete(&mapping->page_tree, page->index);
page->mapping = NULL;
mapping->nrpages--;
BUG_ON(!PageLocked(page));
- write_lock_irq(&mapping->tree_lock);
+ spin_lock_irq(&mapping->tree_lock);
__remove_from_page_cache(page);
- write_unlock_irq(&mapping->tree_lock);
+ spin_unlock_irq(&mapping->tree_lock);
}
static int sync_page(void *word)
}
/**
- * add_to_page_cache - add newly allocated pagecache pages
+ * add_to_page_cache_locked - add a locked page to the pagecache
* @page: page to add
* @mapping: the page's address_space
* @offset: page index
* @gfp_mask: page allocation mode
*
- * This function is used to add newly allocated pagecache pages;
- * the page is new, so we can just run SetPageLocked() against it.
- * The other page state flags were set by rmqueue().
- *
+ * This function is used to add a page to the pagecache. It must be locked.
* This function does not add the page to the LRU. The caller must do that.
*/
-int add_to_page_cache(struct page *page, struct address_space *mapping,
+int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
pgoff_t offset, gfp_t gfp_mask)
{
- int error = mem_cgroup_cache_charge(page, current->mm,
+ int error;
+
+ VM_BUG_ON(!PageLocked(page));
+
+ error = mem_cgroup_cache_charge(page, current->mm,
gfp_mask & ~__GFP_HIGHMEM);
if (error)
goto out;
error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM);
if (error == 0) {
- write_lock_irq(&mapping->tree_lock);
+ page_cache_get(page);
+ page->mapping = mapping;
+ page->index = offset;
+
+ spin_lock_irq(&mapping->tree_lock);
error = radix_tree_insert(&mapping->page_tree, offset, page);
- if (!error) {
- page_cache_get(page);
- SetPageLocked(page);
- page->mapping = mapping;
- page->index = offset;
+ if (likely(!error)) {
mapping->nrpages++;
__inc_zone_page_state(page, NR_FILE_PAGES);
- } else
- mem_cgroup_uncharge_page(page);
+ } else {
+ page->mapping = NULL;
+ mem_cgroup_uncharge_cache_page(page);
+ page_cache_release(page);
+ }
- write_unlock_irq(&mapping->tree_lock);
+ spin_unlock_irq(&mapping->tree_lock);
radix_tree_preload_end();
} else
- mem_cgroup_uncharge_page(page);
+ mem_cgroup_uncharge_cache_page(page);
out:
return error;
}
-EXPORT_SYMBOL(add_to_page_cache);
+EXPORT_SYMBOL(add_to_page_cache_locked);
int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
pgoff_t offset, gfp_t gfp_mask)
* Is there a pagecache struct page at the given (mapping, offset) tuple?
* If yes, increment its refcount and return it; if no, return NULL.
*/
-struct page * find_get_page(struct address_space *mapping, pgoff_t offset)
+struct page *find_get_page(struct address_space *mapping, pgoff_t offset)
{
+ void **pagep;
struct page *page;
- read_lock_irq(&mapping->tree_lock);
- page = radix_tree_lookup(&mapping->page_tree, offset);
- if (page)
- page_cache_get(page);
- read_unlock_irq(&mapping->tree_lock);
+ rcu_read_lock();
+repeat:
+ page = NULL;
+ pagep = radix_tree_lookup_slot(&mapping->page_tree, offset);
+ if (pagep) {
+ page = radix_tree_deref_slot(pagep);
+ if (unlikely(!page || page == RADIX_TREE_RETRY))
+ goto repeat;
+
+ if (!page_cache_get_speculative(page))
+ goto repeat;
+
+ /*
+ * Has the page moved?
+ * This is part of the lockless pagecache protocol. See
+ * include/linux/pagemap.h for details.
+ */
+ if (unlikely(page != *pagep)) {
+ page_cache_release(page);
+ goto repeat;
+ }
+ }
+ rcu_read_unlock();
+
return page;
}
EXPORT_SYMBOL(find_get_page);
*
* Returns zero if the page was not present. find_lock_page() may sleep.
*/
-struct page *find_lock_page(struct address_space *mapping,
- pgoff_t offset)
+struct page *find_lock_page(struct address_space *mapping, pgoff_t offset)
{
struct page *page;
repeat:
- read_lock_irq(&mapping->tree_lock);
- page = radix_tree_lookup(&mapping->page_tree, offset);
+ page = find_get_page(mapping, offset);
if (page) {
- page_cache_get(page);
- if (TestSetPageLocked(page)) {
- read_unlock_irq(&mapping->tree_lock);
- __lock_page(page);
-
- /* Has the page been truncated while we slept? */
- if (unlikely(page->mapping != mapping)) {
- unlock_page(page);
- page_cache_release(page);
- goto repeat;
- }
- VM_BUG_ON(page->index != offset);
- goto out;
+ lock_page(page);
+ /* Has the page been truncated? */
+ if (unlikely(page->mapping != mapping)) {
+ unlock_page(page);
+ page_cache_release(page);
+ goto repeat;
}
+ VM_BUG_ON(page->index != offset);
}
- read_unlock_irq(&mapping->tree_lock);
-out:
return page;
}
EXPORT_SYMBOL(find_lock_page);
{
unsigned int i;
unsigned int ret;
+ unsigned int nr_found;
+
+ rcu_read_lock();
+restart:
+ nr_found = radix_tree_gang_lookup_slot(&mapping->page_tree,
+ (void ***)pages, start, nr_pages);
+ ret = 0;
+ for (i = 0; i < nr_found; i++) {
+ struct page *page;
+repeat:
+ page = radix_tree_deref_slot((void **)pages[i]);
+ if (unlikely(!page))
+ continue;
+ /*
+ * this can only trigger if nr_found == 1, making livelock
+ * a non issue.
+ */
+ if (unlikely(page == RADIX_TREE_RETRY))
+ goto restart;
+
+ if (!page_cache_get_speculative(page))
+ goto repeat;
+
+ /* Has the page moved? */
+ if (unlikely(page != *((void **)pages[i]))) {
+ page_cache_release(page);
+ goto repeat;
+ }
- read_lock_irq(&mapping->tree_lock);
- ret = radix_tree_gang_lookup(&mapping->page_tree,
- (void **)pages, start, nr_pages);
- for (i = 0; i < ret; i++)
- page_cache_get(pages[i]);
- read_unlock_irq(&mapping->tree_lock);
+ pages[ret] = page;
+ ret++;
+ }
+ rcu_read_unlock();
return ret;
}
{
unsigned int i;
unsigned int ret;
+ unsigned int nr_found;
+
+ rcu_read_lock();
+restart:
+ nr_found = radix_tree_gang_lookup_slot(&mapping->page_tree,
+ (void ***)pages, index, nr_pages);
+ ret = 0;
+ for (i = 0; i < nr_found; i++) {
+ struct page *page;
+repeat:
+ page = radix_tree_deref_slot((void **)pages[i]);
+ if (unlikely(!page))
+ continue;
+ /*
+ * this can only trigger if nr_found == 1, making livelock
+ * a non issue.
+ */
+ if (unlikely(page == RADIX_TREE_RETRY))
+ goto restart;
- read_lock_irq(&mapping->tree_lock);
- ret = radix_tree_gang_lookup(&mapping->page_tree,
- (void **)pages, index, nr_pages);
- for (i = 0; i < ret; i++) {
- if (pages[i]->mapping == NULL || pages[i]->index != index)
+ if (page->mapping == NULL || page->index != index)
break;
- page_cache_get(pages[i]);
+ if (!page_cache_get_speculative(page))
+ goto repeat;
+
+ /* Has the page moved? */
+ if (unlikely(page != *((void **)pages[i]))) {
+ page_cache_release(page);
+ goto repeat;
+ }
+
+ pages[ret] = page;
+ ret++;
index++;
}
- read_unlock_irq(&mapping->tree_lock);
- return i;
+ rcu_read_unlock();
+ return ret;
}
EXPORT_SYMBOL(find_get_pages_contig);
{
unsigned int i;
unsigned int ret;
+ unsigned int nr_found;
+
+ rcu_read_lock();
+restart:
+ nr_found = radix_tree_gang_lookup_tag_slot(&mapping->page_tree,
+ (void ***)pages, *index, nr_pages, tag);
+ ret = 0;
+ for (i = 0; i < nr_found; i++) {
+ struct page *page;
+repeat:
+ page = radix_tree_deref_slot((void **)pages[i]);
+ if (unlikely(!page))
+ continue;
+ /*
+ * this can only trigger if nr_found == 1, making livelock
+ * a non issue.
+ */
+ if (unlikely(page == RADIX_TREE_RETRY))
+ goto restart;
+
+ if (!page_cache_get_speculative(page))
+ goto repeat;
+
+ /* Has the page moved? */
+ if (unlikely(page != *((void **)pages[i]))) {
+ page_cache_release(page);
+ goto repeat;
+ }
+
+ pages[ret] = page;
+ ret++;
+ }
+ rcu_read_unlock();
- read_lock_irq(&mapping->tree_lock);
- ret = radix_tree_gang_lookup_tag(&mapping->page_tree,
- (void **)pages, *index, nr_pages, tag);
- for (i = 0; i < ret; i++)
- page_cache_get(pages[i]);
if (ret)
*index = pages[ret - 1]->index + 1;
- read_unlock_irq(&mapping->tree_lock);
+
return ret;
}
EXPORT_SYMBOL(find_get_pages_tag);
mapping = filp->f_mapping;
inode = mapping->host;
- retval = 0;
if (!count)
goto out; /* skip atime */
size = i_size_read(inode);
if (pos < size) {
- retval = generic_file_direct_IO(READ, iocb,
- iov, pos, nr_segs);
+ retval = filemap_write_and_wait(mapping);
+ if (!retval) {
+ retval = mapping->a_ops->direct_IO(READ, iocb,
+ iov, pos, nr_segs);
+ }
if (retval > 0)
*ppos = pos + retval;
- }
- if (likely(retval != 0)) {
- file_accessed(filp);
- goto out;
+ if (retval) {
+ file_accessed(filp);
+ goto out;
+ }
}
}
- retval = 0;
- if (count) {
- for (seg = 0; seg < nr_segs; seg++) {
- read_descriptor_t desc;
+ for (seg = 0; seg < nr_segs; seg++) {
+ read_descriptor_t desc;
- desc.written = 0;
- desc.arg.buf = iov[seg].iov_base;
- desc.count = iov[seg].iov_len;
- if (desc.count == 0)
- continue;
- desc.error = 0;
- do_generic_file_read(filp,ppos,&desc,file_read_actor);
- retval += desc.written;
- if (desc.error) {
- retval = retval ?: desc.error;
- break;
- }
- if (desc.count > 0)
- break;
+ desc.written = 0;
+ desc.arg.buf = iov[seg].iov_base;
+ desc.count = iov[seg].iov_len;
+ if (desc.count == 0)
+ continue;
+ desc.error = 0;
+ do_generic_file_read(filp, ppos, &desc, file_read_actor);
+ retval += desc.written;
+ if (desc.error) {
+ retval = retval ?: desc.error;
+ break;
}
+ if (desc.count > 0)
+ break;
}
out:
return retval;
return notify_change(dentry, &newattrs);
}
-int remove_suid(struct dentry *dentry)
+int file_remove_suid(struct file *file)
{
+ struct dentry *dentry = file->f_path.dentry;
int killsuid = should_remove_suid(dentry);
int killpriv = security_inode_need_killpriv(dentry);
int error = 0;
return error;
}
-EXPORT_SYMBOL(remove_suid);
+EXPORT_SYMBOL(file_remove_suid);
static size_t __iovec_copy_from_user_inatomic(char *vaddr,
const struct iovec *iov, size_t base, size_t bytes)
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
ssize_t written;
+ size_t write_len;
+ pgoff_t end;
if (count != ocount)
*nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count);
- written = generic_file_direct_IO(WRITE, iocb, iov, pos, *nr_segs);
+ /*
+ * Unmap all mmappings of the file up-front.
+ *
+ * This will cause any pte dirty bits to be propagated into the
+ * pageframes for the subsequent filemap_write_and_wait().
+ */
+ write_len = iov_length(iov, *nr_segs);
+ end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT;
+ if (mapping_mapped(mapping))
+ unmap_mapping_range(mapping, pos, write_len, 0);
+
+ written = filemap_write_and_wait(mapping);
+ if (written)
+ goto out;
+
+ /*
+ * After a write we want buffered reads to be sure to go to disk to get
+ * the new data. We invalidate clean cached page from the region we're
+ * about to write. We do this *before* the write so that we can return
+ * -EIO without clobbering -EIOCBQUEUED from ->direct_IO().
+ */
+ if (mapping->nrpages) {
+ written = invalidate_inode_pages2_range(mapping,
+ pos >> PAGE_CACHE_SHIFT, end);
+ if (written)
+ goto out;
+ }
+
+ written = mapping->a_ops->direct_IO(WRITE, iocb, iov, pos, *nr_segs);
+
+ /*
+ * Finally, try again to invalidate clean pages which might have been
+ * cached by non-direct readahead, or faulted in by get_user_pages()
+ * if the source of the write was an mmap'ed region of the file
+ * we're writing. Either one is a pretty crazy thing to do,
+ * so we don't support it 100%. If this invalidation
+ * fails, tough, the write still worked...
+ */
+ if (mapping->nrpages) {
+ invalidate_inode_pages2_range(mapping,
+ pos >> PAGE_CACHE_SHIFT, end);
+ }
+
if (written > 0) {
loff_t end = pos + written;
if (end > i_size_read(inode) && !S_ISBLK(inode->i_mode)) {
* i_mutex is held, which protects generic_osync_inode() from
* livelocking. AIO O_DIRECT ops attempt to sync metadata here.
*/
+out:
if ((written >= 0 || written == -EIOCBQUEUED) &&
((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
int err = generic_osync_inode(inode, mapping, OSYNC_METADATA);
if (count == 0)
goto out;
- err = remove_suid(file->f_path.dentry);
+ err = file_remove_suid(file);
if (err)
goto out;
}
EXPORT_SYMBOL(generic_file_aio_write);
-/*
- * Called under i_mutex for writes to S_ISREG files. Returns -EIO if something
- * went wrong during pagecache shootdown.
- */
-static ssize_t
-generic_file_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
- loff_t offset, unsigned long nr_segs)
-{
- struct file *file = iocb->ki_filp;
- struct address_space *mapping = file->f_mapping;
- ssize_t retval;
- size_t write_len;
- pgoff_t end = 0; /* silence gcc */
-
- /*
- * If it's a write, unmap all mmappings of the file up-front. This
- * will cause any pte dirty bits to be propagated into the pageframes
- * for the subsequent filemap_write_and_wait().
- */
- if (rw == WRITE) {
- write_len = iov_length(iov, nr_segs);
- end = (offset + write_len - 1) >> PAGE_CACHE_SHIFT;
- if (mapping_mapped(mapping))
- unmap_mapping_range(mapping, offset, write_len, 0);
- }
-
- retval = filemap_write_and_wait(mapping);
- if (retval)
- goto out;
-
- /*
- * After a write we want buffered reads to be sure to go to disk to get
- * the new data. We invalidate clean cached page from the region we're
- * about to write. We do this *before* the write so that we can return
- * -EIO without clobbering -EIOCBQUEUED from ->direct_IO().
- */
- if (rw == WRITE && mapping->nrpages) {
- retval = invalidate_inode_pages2_range(mapping,
- offset >> PAGE_CACHE_SHIFT, end);
- if (retval)
- goto out;
- }
-
- retval = mapping->a_ops->direct_IO(rw, iocb, iov, offset, nr_segs);
-
- /*
- * Finally, try again to invalidate clean pages which might have been
- * cached by non-direct readahead, or faulted in by get_user_pages()
- * if the source of the write was an mmap'ed region of the file
- * we're writing. Either one is a pretty crazy thing to do,
- * so we don't support it 100%. If this invalidation
- * fails, tough, the write still worked...
- */
- if (rw == WRITE && mapping->nrpages) {
- invalidate_inode_pages2_range(mapping, offset >> PAGE_CACHE_SHIFT, end);
- }
-out:
- return retval;
-}
-
/**
* try_to_release_page() - release old fs-specific metadata on a page
*
* Otherwise return zero.
*
* The @gfp_mask argument specifies whether I/O may be performed to release
- * this page (__GFP_IO), and whether the call may block (__GFP_WAIT).
+ * this page (__GFP_IO), and whether the call may block (__GFP_WAIT & __GFP_FS).
*
- * NOTE: @gfp_mask may go away, and this function may become non-blocking.
*/
int try_to_release_page(struct page *page, gfp_t gfp_mask)
{
projects / linux-2.6-omap-h63xx.git / blobdiff