* most "normal" filesystems (but you don't /have/ to use this:
* the NFS filesystem used to do this differently, for example)
*/
-#include <linux/config.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/compiler.h>
#include <linux/fs.h>
+#include <linux/uaccess.h>
#include <linux/aio.h>
+#include <linux/capability.h>
#include <linux/kernel_stat.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/blkdev.h>
#include <linux/security.h>
#include <linux/syscalls.h>
+#include <linux/cpuset.h>
#include "filemap.h"
+#include "internal.h"
+
/*
* FIXME: remove all knowledge of the buffer layer from the core VM
*/
#include <linux/buffer_head.h> /* for generic_osync_inode */
-#include <asm/uaccess.h>
#include <asm/mman.h>
static ssize_t
* ->swap_lock (exclusive_swap_page, others)
* ->mapping->tree_lock
*
- * ->i_sem
+ * ->i_mutex
* ->i_mmap_lock (truncate->unmap_mapping_range)
*
* ->mmap_sem
* ->i_mmap_lock
- * ->page_table_lock (various places, mainly in mmap.c)
+ * ->page_table_lock or pte_lock (various, mainly in memory.c)
* ->mapping->tree_lock (arch-dependent flush_dcache_mmap_lock)
*
* ->mmap_sem
* ->lock_page (access_process_vm)
*
* ->mmap_sem
- * ->i_sem (msync)
+ * ->i_mutex (msync)
*
- * ->i_sem
+ * ->i_mutex
* ->i_alloc_sem (various)
*
* ->inode_lock
* ->anon_vma.lock (vma_adjust)
*
* ->anon_vma.lock
- * ->page_table_lock (anon_vma_prepare and various)
+ * ->page_table_lock or pte_lock (anon_vma_prepare and various)
*
- * ->page_table_lock
+ * ->page_table_lock or pte_lock
* ->swap_lock (try_to_unmap_one)
* ->private_lock (try_to_unmap_one)
* ->tree_lock (try_to_unmap_one)
* ->zone.lru_lock (follow_page->mark_page_accessed)
+ * ->zone.lru_lock (check_pte_range->isolate_lru_page)
* ->private_lock (page_remove_rmap->set_page_dirty)
* ->tree_lock (page_remove_rmap->set_page_dirty)
* ->inode_lock (page_remove_rmap->set_page_dirty)
radix_tree_delete(&mapping->page_tree, page->index);
page->mapping = NULL;
mapping->nrpages--;
- pagecache_acct(-1);
+ __dec_zone_page_state(page, NR_FILE_PAGES);
}
void remove_from_page_cache(struct page *page)
struct address_space *mapping;
struct page *page;
- page = container_of((page_flags_t *)word, struct page, flags);
+ page = container_of((unsigned long *)word, struct page, flags);
/*
* page_mapping() is being called without PG_locked held.
* in the ->sync_page() methods make essential use of the
* page_mapping(), merely passing the page down to the backing
* device's unplug functions when it's non-NULL, which in turn
- * ignore it for all cases but swap, where only page->private is
+ * ignore it for all cases but swap, where only page_private(page) is
* of interest. When page_mapping() does go NULL, the entire
* call stack gracefully ignores the page and returns.
* -- wli
}
/**
- * filemap_fdatawrite_range - start writeback against all of a mapping's
- * dirty pages that lie within the byte offsets <start, end>
+ * __filemap_fdatawrite_range - start writeback on mapping dirty pages in range
* @mapping: address space structure to write
* @start: offset in bytes where the range starts
- * @end: offset in bytes where the range ends
+ * @end: offset in bytes where the range ends (inclusive)
* @sync_mode: enable synchronous operation
*
+ * Start writeback against all of a mapping's dirty pages that lie
+ * within the byte offsets <start, end> inclusive.
+ *
* If sync_mode is WB_SYNC_ALL then this is a "data integrity" operation, as
- * opposed to a regular memory * cleansing writeback. The difference between
+ * opposed to a regular memory cleansing writeback. The difference between
* these two operations is that if a dirty page/buffer is encountered, it must
* be waited upon, and not just skipped over.
*/
-static int __filemap_fdatawrite_range(struct address_space *mapping,
- loff_t start, loff_t end, int sync_mode)
+int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
+ loff_t end, int sync_mode)
{
int ret;
struct writeback_control wbc = {
.sync_mode = sync_mode,
.nr_to_write = mapping->nrpages * 2,
- .start = start,
- .end = end,
+ .range_start = start,
+ .range_end = end,
};
if (!mapping_cap_writeback_dirty(mapping))
static inline int __filemap_fdatawrite(struct address_space *mapping,
int sync_mode)
{
- return __filemap_fdatawrite_range(mapping, 0, 0, sync_mode);
+ return __filemap_fdatawrite_range(mapping, 0, LLONG_MAX, sync_mode);
}
int filemap_fdatawrite(struct address_space *mapping)
}
EXPORT_SYMBOL(filemap_fdatawrite);
-static int filemap_fdatawrite_range(struct address_space *mapping,
- loff_t start, loff_t end)
+static int filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
+ loff_t end)
{
return __filemap_fdatawrite_range(mapping, start, end, WB_SYNC_ALL);
}
-/*
+/**
+ * filemap_flush - mostly a non-blocking flush
+ * @mapping: target address_space
+ *
* This is a mostly non-blocking flush. Not suitable for data-integrity
* purposes - I/O may not be started against all dirty pages.
*/
}
EXPORT_SYMBOL(filemap_flush);
-/*
+/**
+ * wait_on_page_writeback_range - wait for writeback to complete
+ * @mapping: target address_space
+ * @start: beginning page index
+ * @end: ending page index
+ *
* Wait for writeback to complete against pages indexed by start->end
* inclusive
*/
-static int wait_on_page_writeback_range(struct address_space *mapping,
+int wait_on_page_writeback_range(struct address_space *mapping,
pgoff_t start, pgoff_t end)
{
struct pagevec pvec;
return ret;
}
-/*
+/**
+ * sync_page_range - write and wait on all pages in the passed range
+ * @inode: target inode
+ * @mapping: target address_space
+ * @pos: beginning offset in pages to write
+ * @count: number of bytes to write
+ *
* Write and wait upon all the pages in the passed range. This is a "data
* integrity" operation. It waits upon in-flight writeout before starting and
* waiting upon new writeout. If there was an IO error, return it.
*
- * We need to re-take i_sem during the generic_osync_inode list walk because
+ * We need to re-take i_mutex during the generic_osync_inode list walk because
* it is otherwise livelockable.
*/
int sync_page_range(struct inode *inode, struct address_space *mapping,
- loff_t pos, size_t count)
+ loff_t pos, loff_t count)
{
pgoff_t start = pos >> PAGE_CACHE_SHIFT;
pgoff_t end = (pos + count - 1) >> PAGE_CACHE_SHIFT;
return 0;
ret = filemap_fdatawrite_range(mapping, pos, pos + count - 1);
if (ret == 0) {
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
ret = generic_osync_inode(inode, mapping, OSYNC_METADATA);
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
}
if (ret == 0)
ret = wait_on_page_writeback_range(mapping, start, end);
}
EXPORT_SYMBOL(sync_page_range);
-/*
- * Note: Holding i_sem across sync_page_range_nolock is not a good idea
+/**
+ * sync_page_range_nolock
+ * @inode: target inode
+ * @mapping: target address_space
+ * @pos: beginning offset in pages to write
+ * @count: number of bytes to write
+ *
+ * Note: Holding i_mutex across sync_page_range_nolock is not a good idea
* as it forces O_SYNC writers to different parts of the same file
* to be serialised right until io completion.
*/
-static int sync_page_range_nolock(struct inode *inode,
- struct address_space *mapping,
- loff_t pos, size_t count)
+int sync_page_range_nolock(struct inode *inode, struct address_space *mapping,
+ loff_t pos, loff_t count)
{
pgoff_t start = pos >> PAGE_CACHE_SHIFT;
pgoff_t end = (pos + count - 1) >> PAGE_CACHE_SHIFT;
ret = wait_on_page_writeback_range(mapping, start, end);
return ret;
}
+EXPORT_SYMBOL(sync_page_range_nolock);
/**
- * filemap_fdatawait - walk the list of under-writeback pages of the given
- * address space and wait for all of them.
- *
+ * filemap_fdatawait - wait for all under-writeback pages to complete
* @mapping: address space structure to wait for
+ *
+ * Walk the list of under-writeback pages of the given address space
+ * and wait for all of them.
*/
int filemap_fdatawait(struct address_space *mapping)
{
int filemap_write_and_wait(struct address_space *mapping)
{
- int retval = 0;
+ int err = 0;
if (mapping->nrpages) {
- retval = filemap_fdatawrite(mapping);
- if (retval == 0)
- retval = filemap_fdatawait(mapping);
+ err = filemap_fdatawrite(mapping);
+ /*
+ * Even if the above returned error, the pages may be
+ * written partially (e.g. -ENOSPC), so we wait for it.
+ * But the -EIO is special case, it may indicate the worst
+ * thing (e.g. bug) happened, so we avoid waiting for it.
+ */
+ if (err != -EIO) {
+ int err2 = filemap_fdatawait(mapping);
+ if (!err)
+ err = err2;
+ }
}
- return retval;
+ return err;
}
+EXPORT_SYMBOL(filemap_write_and_wait);
+/**
+ * filemap_write_and_wait_range - write out & wait on a file range
+ * @mapping: the address_space for the pages
+ * @lstart: offset in bytes where the range starts
+ * @lend: offset in bytes where the range ends (inclusive)
+ *
+ * Write out and wait upon file offsets lstart->lend, inclusive.
+ *
+ * Note that `lend' is inclusive (describes the last byte to be written) so
+ * that this function can be used to write to the very end-of-file (end = -1).
+ */
int filemap_write_and_wait_range(struct address_space *mapping,
loff_t lstart, loff_t lend)
{
- int retval = 0;
+ int err = 0;
if (mapping->nrpages) {
- retval = __filemap_fdatawrite_range(mapping, lstart, lend,
- WB_SYNC_ALL);
- if (retval == 0)
- retval = wait_on_page_writeback_range(mapping,
- lstart >> PAGE_CACHE_SHIFT,
- lend >> PAGE_CACHE_SHIFT);
+ err = __filemap_fdatawrite_range(mapping, lstart, lend,
+ WB_SYNC_ALL);
+ /* See comment of filemap_write_and_wait() */
+ if (err != -EIO) {
+ int err2 = wait_on_page_writeback_range(mapping,
+ lstart >> PAGE_CACHE_SHIFT,
+ lend >> PAGE_CACHE_SHIFT);
+ if (!err)
+ err = err2;
+ }
}
- return retval;
+ return err;
}
-/*
- * This function is used to add newly allocated pagecache pages:
+/**
+ * add_to_page_cache - add newly allocated pagecache pages
+ * @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().
*
page->mapping = mapping;
page->index = offset;
mapping->nrpages++;
- pagecache_acct(1);
+ __inc_zone_page_state(page, NR_FILE_PAGES);
}
write_unlock_irq(&mapping->tree_lock);
radix_tree_preload_end();
}
return error;
}
-
EXPORT_SYMBOL(add_to_page_cache);
int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
return ret;
}
+#ifdef CONFIG_NUMA
+struct page *page_cache_alloc(struct address_space *x)
+{
+ if (cpuset_do_page_mem_spread()) {
+ int n = cpuset_mem_spread_node();
+ return alloc_pages_node(n, mapping_gfp_mask(x), 0);
+ }
+ return alloc_pages(mapping_gfp_mask(x), 0);
+}
+EXPORT_SYMBOL(page_cache_alloc);
+
+struct page *page_cache_alloc_cold(struct address_space *x)
+{
+ if (cpuset_do_page_mem_spread()) {
+ int n = cpuset_mem_spread_node();
+ return alloc_pages_node(n, mapping_gfp_mask(x)|__GFP_COLD, 0);
+ }
+ return alloc_pages(mapping_gfp_mask(x)|__GFP_COLD, 0);
+}
+EXPORT_SYMBOL(page_cache_alloc_cold);
+#endif
+
/*
* In order to wait for pages to become available there must be
* waitqueues associated with pages. By using a hash table of
EXPORT_SYMBOL(wait_on_page_bit);
/**
- * unlock_page() - unlock a locked page
- *
+ * unlock_page - unlock a locked page
* @page: the page
*
* Unlocks the page and wakes up sleepers in ___wait_on_page_locked().
}
EXPORT_SYMBOL(unlock_page);
-/*
- * End writeback against a page.
+/**
+ * end_page_writeback - end writeback against a page
+ * @page: the page
*/
void end_page_writeback(struct page *page)
{
}
EXPORT_SYMBOL(end_page_writeback);
-/*
- * Get a lock on the page, assuming we need to sleep to get it.
+/**
+ * __lock_page - get a lock on the page, assuming we need to sleep to get it
+ * @page: the page to lock
*
- * Ugly: running sync_page() in state TASK_UNINTERRUPTIBLE is scary. If some
+ * Ugly. Running sync_page() in state TASK_UNINTERRUPTIBLE is scary. If some
* random driver's requestfn sets TASK_RUNNING, we could busywait. However
* chances are that on the second loop, the block layer's plug list is empty,
* so sync_page() will then return in state TASK_UNINTERRUPTIBLE.
}
EXPORT_SYMBOL(__lock_page);
-/*
- * a rather lightweight function, finding and getting a reference to a
+/**
+ * find_get_page - find and get a page reference
+ * @mapping: the address_space to search
+ * @offset: the page index
+ *
+ * A rather lightweight function, finding and getting a reference to a
* hashed page atomically.
*/
struct page * find_get_page(struct address_space *mapping, unsigned long offset)
read_unlock_irq(&mapping->tree_lock);
return page;
}
-
EXPORT_SYMBOL(find_get_page);
-/*
- * Same as above, but trylock it instead of incrementing the count.
+/**
+ * find_trylock_page - find and lock a page
+ * @mapping: the address_space to search
+ * @offset: the page index
+ *
+ * Same as find_get_page(), but trylock it instead of incrementing the count.
*/
struct page *find_trylock_page(struct address_space *mapping, unsigned long offset)
{
read_unlock_irq(&mapping->tree_lock);
return page;
}
-
EXPORT_SYMBOL(find_trylock_page);
/**
* find_lock_page - locate, pin and lock a pagecache page
- *
* @mapping: the address_space to search
* @offset: the page index
*
page_cache_get(page);
if (TestSetPageLocked(page)) {
read_unlock_irq(&mapping->tree_lock);
- lock_page(page);
+ __lock_page(page);
read_lock_irq(&mapping->tree_lock);
/* Has the page been truncated while we slept? */
- if (page->mapping != mapping || page->index != offset) {
+ if (unlikely(page->mapping != mapping ||
+ page->index != offset)) {
unlock_page(page);
page_cache_release(page);
goto repeat;
read_unlock_irq(&mapping->tree_lock);
return page;
}
-
EXPORT_SYMBOL(find_lock_page);
/**
* find_or_create_page - locate or add a pagecache page
- *
* @mapping: the page's address_space
* @index: the page's index into the mapping
* @gfp_mask: page allocation mode
page_cache_release(cached_page);
return page;
}
-
EXPORT_SYMBOL(find_or_create_page);
/**
return ret;
}
-/*
+/**
+ * find_get_pages_contig - gang contiguous pagecache lookup
+ * @mapping: The address_space to search
+ * @index: The starting page index
+ * @nr_pages: The maximum number of pages
+ * @pages: Where the resulting pages are placed
+ *
+ * find_get_pages_contig() works exactly like find_get_pages(), except
+ * that the returned number of pages are guaranteed to be contiguous.
+ *
+ * find_get_pages_contig() returns the number of pages which were found.
+ */
+unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index,
+ unsigned int nr_pages, struct page **pages)
+{
+ unsigned int i;
+ unsigned int ret;
+
+ 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)
+ break;
+
+ page_cache_get(pages[i]);
+ index++;
+ }
+ read_unlock_irq(&mapping->tree_lock);
+ return i;
+}
+
+/**
+ * find_get_pages_tag - find and return pages that match @tag
+ * @mapping: the address_space to search
+ * @index: the starting page index
+ * @tag: the tag index
+ * @nr_pages: the maximum number of pages
+ * @pages: where the resulting pages are placed
+ *
* Like find_get_pages, except we only return pages which are tagged with
- * `tag'. We update *index to index the next page for the traversal.
+ * @tag. We update @index to index the next page for the traversal.
*/
unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index,
int tag, unsigned int nr_pages, struct page **pages)
return ret;
}
-/*
+/**
+ * grab_cache_page_nowait - returns locked page at given index in given cache
+ * @mapping: target address_space
+ * @index: the page index
+ *
* Same as grab_cache_page, but do not wait if the page is unavailable.
* This is intended for speculative data generators, where the data can
* be regenerated if the page couldn't be grabbed. This routine should
}
return page;
}
-
EXPORT_SYMBOL(grab_cache_page_nowait);
/*
+ * CD/DVDs are error prone. When a medium error occurs, the driver may fail
+ * a _large_ part of the i/o request. Imagine the worst scenario:
+ *
+ * ---R__________________________________________B__________
+ * ^ reading here ^ bad block(assume 4k)
+ *
+ * read(R) => miss => readahead(R...B) => media error => frustrating retries
+ * => failing the whole request => read(R) => read(R+1) =>
+ * readahead(R+1...B+1) => bang => read(R+2) => read(R+3) =>
+ * readahead(R+3...B+2) => bang => read(R+3) => read(R+4) =>
+ * readahead(R+4...B+3) => bang => read(R+4) => read(R+5) => ......
+ *
+ * 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)
+{
+ if (!ra->ra_pages)
+ return;
+
+ ra->ra_pages /= 4;
+ printk(KERN_WARNING "Reducing readahead size to %luK\n",
+ ra->ra_pages << (PAGE_CACHE_SHIFT - 10));
+}
+
+/**
+ * do_generic_mapping_read - generic file read routine
+ * @mapping: address_space to be read
+ * @_ra: file's readahead state
+ * @filp: the file to read
+ * @ppos: current file position
+ * @desc: read_descriptor
+ * @actor: read method
+ *
* This is a generic file read routine, and uses the
- * mapping->a_ops->readpage() function for the actual low-level
- * stuff.
+ * mapping->a_ops->readpage() function for the actual low-level stuff.
*
* This is really ugly. But the goto's actually try to clarify some
* of the logic when it comes to error handling etc.
*
- * Note the struct file* is only passed for the use of readpage. It may be
- * NULL.
+ * Note the struct file* is only passed for the use of readpage.
+ * It may be NULL.
*/
void do_generic_mapping_read(struct address_space *mapping,
struct file_ra_state *_ra,
/* Start the actual read. The read will unlock the page. */
error = mapping->a_ops->readpage(filp, page);
- if (unlikely(error))
+ if (unlikely(error)) {
+ if (error == AOP_TRUNCATED_PAGE) {
+ page_cache_release(page);
+ goto find_page;
+ }
goto readpage_error;
+ }
if (!PageUptodate(page)) {
lock_page(page);
}
unlock_page(page);
error = -EIO;
+ shrink_readahead_size_eio(filp, &ra);
goto readpage_error;
}
unlock_page(page);
if (filp)
file_accessed(filp);
}
-
EXPORT_SYMBOL(do_generic_mapping_read);
int file_read_actor(read_descriptor_t *desc, struct page *page,
return size;
}
-/*
+/**
+ * __generic_file_aio_read - generic filesystem read routine
+ * @iocb: kernel I/O control block
+ * @iov: io vector request
+ * @nr_segs: number of segments in the iovec
+ * @ppos: current file position
+ *
* This is the "read()" routine for all filesystems
* that can use the page cache directly.
*/
desc.error = 0;
do_generic_file_read(filp,ppos,&desc,file_read_actor);
retval += desc.written;
- if (!retval) {
- retval = desc.error;
+ if (desc.error) {
+ retval = retval ?: desc.error;
break;
}
}
out:
return retval;
}
-
EXPORT_SYMBOL(__generic_file_aio_read);
ssize_t
BUG_ON(iocb->ki_pos != pos);
return __generic_file_aio_read(iocb, &local_iov, 1, &iocb->ki_pos);
}
-
EXPORT_SYMBOL(generic_file_aio_read);
ssize_t
ret = wait_on_sync_kiocb(&kiocb);
return ret;
}
-
EXPORT_SYMBOL(generic_file_read);
int file_send_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size)
return desc.written;
return desc.error;
}
-
EXPORT_SYMBOL(generic_file_sendfile);
static ssize_t
}
#ifdef CONFIG_MMU
-/*
+static int FASTCALL(page_cache_read(struct file * file, unsigned long offset));
+/**
+ * page_cache_read - adds requested page to the page cache if not already there
+ * @file: file to read
+ * @offset: page index
+ *
* This adds the requested page to the page cache if it isn't already there,
* and schedules an I/O to read in its contents from disk.
*/
-static int FASTCALL(page_cache_read(struct file * file, unsigned long offset));
static int fastcall page_cache_read(struct file * file, unsigned long offset)
{
struct address_space *mapping = file->f_mapping;
struct page *page;
- int error;
+ int ret;
- page = page_cache_alloc_cold(mapping);
- if (!page)
- return -ENOMEM;
+ do {
+ page = page_cache_alloc_cold(mapping);
+ if (!page)
+ return -ENOMEM;
+
+ ret = add_to_page_cache_lru(page, mapping, offset, GFP_KERNEL);
+ if (ret == 0)
+ ret = mapping->a_ops->readpage(file, page);
+ else if (ret == -EEXIST)
+ ret = 0; /* losing race to add is OK */
- error = add_to_page_cache_lru(page, mapping, offset, GFP_KERNEL);
- if (!error) {
- error = mapping->a_ops->readpage(file, page);
page_cache_release(page);
- return error;
- }
- /*
- * We arrive here in the unlikely event that someone
- * raced with us and added our page to the cache first
- * or we are out of memory for radix-tree nodes.
- */
- page_cache_release(page);
- return error == -EEXIST ? 0 : error;
+ } while (ret == AOP_TRUNCATED_PAGE);
+
+ return ret;
}
#define MMAP_LOTSAMISS (100)
-/*
+/**
+ * filemap_nopage - read in file data for page fault handling
+ * @area: the applicable vm_area
+ * @address: target address to read in
+ * @type: returned with VM_FAULT_{MINOR,MAJOR} if not %NULL
+ *
* filemap_nopage() is invoked via the vma operations vector for a
* mapped memory region to read in file data during a page fault.
*
*/
if (!did_readaround) {
majmin = VM_FAULT_MAJOR;
- inc_page_state(pgmajfault);
+ count_vm_event(PGMAJFAULT);
}
did_readaround = 1;
ra_pages = max_sane_readahead(file->f_ra.ra_pages);
page_not_uptodate:
if (!did_readaround) {
majmin = VM_FAULT_MAJOR;
- inc_page_state(pgmajfault);
+ count_vm_event(PGMAJFAULT);
}
lock_page(page);
goto success;
}
- if (!mapping->a_ops->readpage(file, page)) {
+ error = mapping->a_ops->readpage(file, page);
+ if (!error) {
wait_on_page_locked(page);
if (PageUptodate(page))
goto success;
+ } else if (error == AOP_TRUNCATED_PAGE) {
+ page_cache_release(page);
+ goto retry_find;
}
/*
goto success;
}
ClearPageError(page);
- if (!mapping->a_ops->readpage(file, page)) {
+ error = mapping->a_ops->readpage(file, page);
+ if (!error) {
wait_on_page_locked(page);
if (PageUptodate(page))
goto success;
+ } else if (error == AOP_TRUNCATED_PAGE) {
+ page_cache_release(page);
+ goto retry_find;
}
/*
* Things didn't work out. Return zero to tell the
* mm layer so, possibly freeing the page cache page first.
*/
+ shrink_readahead_size_eio(file, ra);
page_cache_release(page);
return NULL;
}
-
EXPORT_SYMBOL(filemap_nopage);
static struct page * filemap_getpage(struct file *file, unsigned long pgoff,
goto success;
}
- if (!mapping->a_ops->readpage(file, page)) {
+ error = mapping->a_ops->readpage(file, page);
+ if (!error) {
wait_on_page_locked(page);
if (PageUptodate(page))
goto success;
+ } else if (error == AOP_TRUNCATED_PAGE) {
+ page_cache_release(page);
+ goto retry_find;
}
/*
}
ClearPageError(page);
- if (!mapping->a_ops->readpage(file, page)) {
+ error = mapping->a_ops->readpage(file, page);
+ if (!error) {
wait_on_page_locked(page);
if (PageUptodate(page))
goto success;
+ } else if (error == AOP_TRUNCATED_PAGE) {
+ page_cache_release(page);
+ goto retry_find;
}
/*
return 0;
}
+EXPORT_SYMBOL(filemap_populate);
struct vm_operations_struct generic_file_vm_ops = {
.nopage = filemap_nopage,
vma->vm_ops = &generic_file_vm_ops;
return 0;
}
-EXPORT_SYMBOL(filemap_populate);
/*
* This is for filesystems which do not implement ->writepage.
return page;
}
-/*
+/**
+ * read_cache_page - read into page cache, fill it if needed
+ * @mapping: the page's address_space
+ * @index: the page index
+ * @filler: function to perform the read
+ * @data: destination for read data
+ *
* Read into the page cache. If a page already exists,
* and PageUptodate() is not set, try to fill the page.
*/
out:
return page;
}
-
EXPORT_SYMBOL(read_cache_page);
/*
EXPORT_SYMBOL(remove_suid);
size_t
-__filemap_copy_from_user_iovec(char *vaddr,
+__filemap_copy_from_user_iovec_inatomic(char *vaddr,
const struct iovec *iov, size_t base, size_t bytes)
{
size_t copied = 0, left = 0;
int copy = min(bytes, iov->iov_len - base);
base = 0;
- left = __copy_from_user_inatomic(vaddr, buf, copy);
+ left = __copy_from_user_inatomic_nocache(vaddr, buf, copy);
copied += copy;
bytes -= copy;
vaddr += copy;
iov++;
- if (unlikely(left)) {
- /* zero the rest of the target like __copy_from_user */
- if (bytes)
- memset(vaddr, 0, bytes);
+ if (unlikely(left))
break;
- }
}
return copied - left;
}
/*
* Performs necessary checks before doing a write
*
- * Can adjust writing position aor amount of bytes to write.
+ * Can adjust writing position or amount of bytes to write.
* Returns appropriate error code that caller should return or
* zero in case that write should be allowed.
*/
/*
* Sync the fs metadata but not the minor inode changes and
* of course not the data as we did direct DMA for the IO.
- * i_sem is held, which protects generic_osync_inode() from
+ * i_mutex is held, which protects generic_osync_inode() from
* livelocking.
*/
if (written >= 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
{
struct file *file = iocb->ki_filp;
struct address_space * mapping = file->f_mapping;
- struct address_space_operations *a_ops = mapping->a_ops;
+ const struct address_space_operations *a_ops = mapping->a_ops;
struct inode *inode = mapping->host;
long status = 0;
struct page *page;
do {
unsigned long index;
unsigned long offset;
- unsigned long maxlen;
size_t copied;
offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
index = pos >> PAGE_CACHE_SHIFT;
bytes = PAGE_CACHE_SIZE - offset;
- if (bytes > count)
- bytes = count;
+
+ /* Limit the size of the copy to the caller's write size */
+ bytes = min(bytes, count);
+
+ /*
+ * Limit the size of the copy to that of the current segment,
+ * because fault_in_pages_readable() doesn't know how to walk
+ * segments.
+ */
+ bytes = min(bytes, cur_iov->iov_len - iov_base);
/*
* Bring in the user page that we will copy from _first_.
* same page as we're writing to, without it being marked
* up-to-date.
*/
- maxlen = cur_iov->iov_len - iov_base;
- if (maxlen > bytes)
- maxlen = bytes;
- fault_in_pages_readable(buf, maxlen);
+ fault_in_pages_readable(buf, bytes);
page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec);
if (!page) {
break;
}
+ if (unlikely(bytes == 0)) {
+ status = 0;
+ copied = 0;
+ goto zero_length_segment;
+ }
+
status = a_ops->prepare_write(file, page, offset, offset+bytes);
if (unlikely(status)) {
loff_t isize = i_size_read(inode);
+
+ if (status != AOP_TRUNCATED_PAGE)
+ unlock_page(page);
+ page_cache_release(page);
+ if (status == AOP_TRUNCATED_PAGE)
+ continue;
/*
* prepare_write() may have instantiated a few blocks
* outside i_size. Trim these off again.
*/
- unlock_page(page);
- page_cache_release(page);
if (pos + bytes > isize)
vmtruncate(inode, isize);
break;
cur_iov, iov_base, bytes);
flush_dcache_page(page);
status = a_ops->commit_write(file, page, offset, offset+bytes);
- if (likely(copied > 0)) {
+ if (status == AOP_TRUNCATED_PAGE) {
+ page_cache_release(page);
+ continue;
+ }
+zero_length_segment:
+ if (likely(copied >= 0)) {
if (!status)
status = copied;
unsigned long nr_segs, loff_t *ppos)
{
struct file *file = iocb->ki_filp;
- struct address_space * mapping = file->f_mapping;
+ const struct address_space * mapping = file->f_mapping;
size_t ocount; /* original count */
size_t count; /* after file limit checks */
struct inode *inode = mapping->host;
if (err)
goto out;
- inode_update_time(inode, 1);
+ file_update_time(file);
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
if (unlikely(file->f_flags & O_DIRECT)) {
BUG_ON(iocb->ki_pos != pos);
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
ret = __generic_file_aio_write_nolock(iocb, &local_iov, 1,
&iocb->ki_pos);
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
ssize_t err;
struct iovec local_iov = { .iov_base = (void __user *)buf,
.iov_len = count };
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
ret = __generic_file_write_nolock(file, &local_iov, 1, ppos);
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
ssize_t err;
struct inode *inode = mapping->host;
ssize_t ret;
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
ret = __generic_file_write_nolock(file, iov, nr_segs, ppos);
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
int err;
EXPORT_SYMBOL(generic_file_writev);
/*
- * Called under i_sem for writes to S_ISREG files. Returns -EIO if something
+ * Called under i_mutex for writes to S_ISREG files. Returns -EIO if something
* went wrong during pagecache shootdown.
*/
static ssize_t
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff