* the NFS filesystem used to do this differently, for example)
*/
#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/gfp.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/mman.h>
#include <linux/cpuset.h>
#include <linux/hardirq.h> /* for BUG_ON(!in_atomic()) only */
#include <linux/memcontrol.h>
+#include <linux/mm_inline.h> /* for page_is_file_cache() */
#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 <linux/buffer_head.h> /* for try_to_free_buffers */
#include <asm/mman.h>
-
/*
* Shared mappings implemented 30.11.1994. It's not fully working yet,
* though.
/*
* Lock ordering:
*
- * ->i_mmap_lock (vmtruncate)
+ * ->i_mmap_lock (truncate_pagecache)
* ->private_lock (__free_pte->__set_page_dirty_buffers)
* ->swap_lock (exclusive_swap_page, others)
* ->mapping->tree_lock
*
* ->task->proc_lock
* ->dcache_lock (proc_pid_lookup)
+ *
+ * (code doesn't rely on that order, so you could switch it around)
+ * ->tasklist_lock (memory_failure, collect_procs_ao)
+ * ->i_mmap_lock
*/
/*
{
struct address_space *mapping = page->mapping;
- mem_cgroup_uncharge_cache_page(page);
radix_tree_delete(&mapping->page_tree, page->index);
page->mapping = NULL;
mapping->nrpages--;
__dec_zone_page_state(page, NR_FILE_PAGES);
+ if (PageSwapBacked(page))
+ __dec_zone_page_state(page, NR_SHMEM);
BUG_ON(page_mapped(page));
/*
spin_lock_irq(&mapping->tree_lock);
__remove_from_page_cache(page);
spin_unlock_irq(&mapping->tree_lock);
+ mem_cgroup_uncharge_cache_page(page);
}
static int sync_page(void *word)
int ret;
struct writeback_control wbc = {
.sync_mode = sync_mode,
- .nr_to_write = mapping->nrpages * 2,
+ .nr_to_write = LONG_MAX,
.range_start = start,
.range_end = end,
};
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
+ * filemap_fdatawait_range - wait for writeback to complete
+ * @mapping: address space structure to wait for
+ * @start_byte: offset in bytes where the range starts
+ * @end_byte: offset in bytes where the range ends (inclusive)
*
- * Wait for writeback to complete against pages indexed by start->end
- * inclusive
+ * Walk the list of under-writeback pages of the given address space
+ * in the given range and wait for all of them.
*/
-int wait_on_page_writeback_range(struct address_space *mapping,
- pgoff_t start, pgoff_t end)
+int filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte,
+ loff_t end_byte)
{
+ pgoff_t index = start_byte >> PAGE_CACHE_SHIFT;
+ pgoff_t end = end_byte >> PAGE_CACHE_SHIFT;
struct pagevec pvec;
int nr_pages;
int ret = 0;
- pgoff_t index;
- if (end < start)
+ if (end_byte < start_byte)
return 0;
pagevec_init(&pvec, 0);
- index = start;
while ((index <= end) &&
(nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
PAGECACHE_TAG_WRITEBACK,
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_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, loff_t count)
-{
- pgoff_t start = pos >> PAGE_CACHE_SHIFT;
- pgoff_t end = (pos + count - 1) >> PAGE_CACHE_SHIFT;
- int ret;
-
- if (!mapping_cap_writeback_dirty(mapping) || !count)
- return 0;
- ret = filemap_fdatawrite_range(mapping, pos, pos + count - 1);
- if (ret == 0) {
- mutex_lock(&inode->i_mutex);
- ret = generic_osync_inode(inode, mapping, OSYNC_METADATA);
- mutex_unlock(&inode->i_mutex);
- }
- if (ret == 0)
- ret = wait_on_page_writeback_range(mapping, start, end);
- return ret;
-}
-EXPORT_SYMBOL(sync_page_range);
-
-/**
- * sync_page_range_nolock - write & wait on all pages in the passed range without locking
- * @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.
- */
-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;
- int ret;
-
- if (!mapping_cap_writeback_dirty(mapping) || !count)
- return 0;
- ret = filemap_fdatawrite_range(mapping, pos, pos + count - 1);
- if (ret == 0)
- ret = generic_osync_inode(inode, mapping, OSYNC_METADATA);
- if (ret == 0)
- ret = wait_on_page_writeback_range(mapping, start, end);
- return ret;
-}
-EXPORT_SYMBOL(sync_page_range_nolock);
+EXPORT_SYMBOL(filemap_fdatawait_range);
/**
* filemap_fdatawait - wait for all under-writeback pages to complete
if (i_size == 0)
return 0;
- return wait_on_page_writeback_range(mapping, 0,
- (i_size - 1) >> PAGE_CACHE_SHIFT);
+ return filemap_fdatawait_range(mapping, 0, i_size - 1);
}
EXPORT_SYMBOL(filemap_fdatawait);
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);
+ int err2 = filemap_fdatawait_range(mapping,
+ lstart, lend);
if (!err)
err = err2;
}
}
return err;
}
+EXPORT_SYMBOL(filemap_write_and_wait_range);
/**
* add_to_page_cache_locked - add a locked page to the pagecache
VM_BUG_ON(!PageLocked(page));
error = mem_cgroup_cache_charge(page, current->mm,
- gfp_mask & ~__GFP_HIGHMEM);
+ gfp_mask & GFP_RECLAIM_MASK);
if (error)
goto out;
if (likely(!error)) {
mapping->nrpages++;
__inc_zone_page_state(page, NR_FILE_PAGES);
+ if (PageSwapBacked(page))
+ __inc_zone_page_state(page, NR_SHMEM);
+ spin_unlock_irq(&mapping->tree_lock);
} else {
page->mapping = NULL;
+ spin_unlock_irq(&mapping->tree_lock);
mem_cgroup_uncharge_cache_page(page);
page_cache_release(page);
}
-
- spin_unlock_irq(&mapping->tree_lock);
radix_tree_preload_end();
} else
mem_cgroup_uncharge_cache_page(page);
int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
pgoff_t offset, gfp_t gfp_mask)
{
- int ret = add_to_page_cache(page, mapping, offset, gfp_mask);
- if (ret == 0)
- lru_cache_add(page);
+ int ret;
+
+ /*
+ * Splice_read and readahead add shmem/tmpfs pages into the page cache
+ * before shmem_readpage has a chance to mark them as SwapBacked: they
+ * need to go on the anon lru below, and mem_cgroup_cache_charge
+ * (called in add_to_page_cache) needs to know where they're going too.
+ */
+ if (mapping_cap_swap_backed(mapping))
+ SetPageSwapBacked(page);
+
+ ret = add_to_page_cache(page, mapping, offset, gfp_mask);
+ if (ret == 0) {
+ if (page_is_file_cache(page))
+ lru_cache_add_file(page);
+ else
+ lru_cache_add_anon(page);
+ }
return ret;
}
+EXPORT_SYMBOL_GPL(add_to_page_cache_lru);
#ifdef CONFIG_NUMA
struct page *__page_cache_alloc(gfp_t gfp)
{
+ int n;
+ struct page *page;
+
if (cpuset_do_page_mem_spread()) {
- int n = cpuset_mem_spread_node();
- return alloc_pages_node(n, gfp, 0);
+ get_mems_allowed();
+ n = cpuset_mem_spread_node();
+ page = alloc_pages_exact_node(n, gfp, 0);
+ put_mems_allowed();
+ return page;
}
return alloc_pages(gfp, 0);
}
EXPORT_SYMBOL(wait_on_page_bit);
/**
+ * add_page_wait_queue - Add an arbitrary waiter to a page's wait queue
+ * @page: Page defining the wait queue of interest
+ * @waiter: Waiter to add to the queue
+ *
+ * Add an arbitrary @waiter to the wait queue for the nominated @page.
+ */
+void add_page_wait_queue(struct page *page, wait_queue_t *waiter)
+{
+ wait_queue_head_t *q = page_waitqueue(page);
+ unsigned long flags;
+
+ spin_lock_irqsave(&q->lock, flags);
+ __add_wait_queue(q, waiter);
+ spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL_GPL(add_page_wait_queue);
+
+/**
* unlock_page - unlock a locked page
* @page: the page
*
* mechananism between PageLocked pages and PageWriteback pages is shared.
* But that's OK - sleepers in wait_on_page_writeback() just go back to sleep.
*
- * The first mb is necessary to safely close the critical section opened by the
- * test_and_set_bit() to lock the page; the second mb is necessary to enforce
- * ordering between the clear_bit and the read of the waitqueue (to avoid SMP
- * races with a parallel wait_on_page_locked()).
+ * The mb is necessary to enforce ordering between the clear_bit and the read
+ * of the waitqueue (to avoid SMP races with a parallel wait_on_page_locked()).
*/
void unlock_page(struct page *page)
{
- smp_mb__before_clear_bit();
- if (!test_and_clear_bit(PG_locked, &page->flags))
- BUG();
- smp_mb__after_clear_bit();
+ VM_BUG_ON(!PageLocked(page));
+ clear_bit_unlock(PG_locked, &page->flags);
+ smp_mb__after_clear_bit();
wake_up_page(page, PG_locked);
}
EXPORT_SYMBOL(unlock_page);
return __wait_on_bit_lock(page_waitqueue(page), &wait,
sync_page_killable, TASK_KILLABLE);
}
+EXPORT_SYMBOL_GPL(__lock_page_killable);
/**
* __lock_page_nosync - get a lock on the page, without calling sync_page()
page = __page_cache_alloc(gfp_mask);
if (!page)
return NULL;
- err = add_to_page_cache_lru(page, mapping, index, gfp_mask);
+ /*
+ * We want a regular kernel memory (not highmem or DMA etc)
+ * allocation for the radix tree nodes, but we need to honour
+ * the context-specific requirements the caller has asked for.
+ * GFP_RECLAIM_MASK collects those requirements.
+ */
+ err = add_to_page_cache_lru(page, mapping, index,
+ (gfp_mask & GFP_RECLAIM_MASK));
if (unlikely(err)) {
page_cache_release(page);
page = NULL;
return NULL;
}
page = __page_cache_alloc(mapping_gfp_mask(mapping) & ~__GFP_FS);
- if (page && add_to_page_cache_lru(page, mapping, index, GFP_KERNEL)) {
+ if (page && add_to_page_cache_lru(page, mapping, index, GFP_NOFS)) {
page_cache_release(page);
page = NULL;
}
static void shrink_readahead_size_eio(struct file *filp,
struct file_ra_state *ra)
{
- if (!ra->ra_pages)
- return;
-
ra->ra_pages /= 4;
}
}
readpage:
+ /*
+ * A previous I/O error may have been due to temporary
+ * failures, eg. multipath errors.
+ * PG_error will be set again if readpage fails.
+ */
+ ClearPageError(page);
/* Start the actual read. The read will unlock the page. */
error = mapping->a_ops->readpage(filp, page);
if (!PageUptodate(page)) {
if (page->mapping == NULL) {
/*
- * invalidate_inode_pages got it
+ * invalidate_mapping_pages got it
*/
unlock_page(page);
page_cache_release(page);
goto out; /* skip atime */
size = i_size_read(inode);
if (pos < size) {
- retval = filemap_write_and_wait(mapping);
+ retval = filemap_write_and_wait_range(mapping, pos,
+ pos + iov_length(iov, nr_segs) - 1);
if (!retval) {
retval = mapping->a_ops->direct_IO(READ, iocb,
iov, pos, nr_segs);
if (!mapping || !mapping->a_ops || !mapping->a_ops->readpage)
return -EINVAL;
- force_page_cache_readahead(mapping, filp, index,
- max_sane_readahead(nr));
+ force_page_cache_readahead(mapping, filp, index, nr);
return 0;
}
-asmlinkage ssize_t sys_readahead(int fd, loff_t offset, size_t count)
+SYSCALL_DEFINE(readahead)(int fd, loff_t offset, size_t count)
{
ssize_t ret;
struct file *file;
}
return ret;
}
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_readahead(long fd, loff_t offset, long count)
+{
+ return SYSC_readahead((int) fd, offset, (size_t) count);
+}
+SYSCALL_ALIAS(sys_readahead, SyS_readahead);
+#endif
#ifdef CONFIG_MMU
/**
#define MMAP_LOTSAMISS (100)
+/*
+ * Synchronous readahead happens when we don't even find
+ * a page in the page cache at all.
+ */
+static void do_sync_mmap_readahead(struct vm_area_struct *vma,
+ struct file_ra_state *ra,
+ struct file *file,
+ pgoff_t offset)
+{
+ unsigned long ra_pages;
+ struct address_space *mapping = file->f_mapping;
+
+ /* If we don't want any read-ahead, don't bother */
+ if (VM_RandomReadHint(vma))
+ return;
+
+ if (VM_SequentialReadHint(vma) ||
+ offset - 1 == (ra->prev_pos >> PAGE_CACHE_SHIFT)) {
+ page_cache_sync_readahead(mapping, ra, file, offset,
+ ra->ra_pages);
+ return;
+ }
+
+ if (ra->mmap_miss < INT_MAX)
+ ra->mmap_miss++;
+
+ /*
+ * Do we miss much more than hit in this file? If so,
+ * stop bothering with read-ahead. It will only hurt.
+ */
+ if (ra->mmap_miss > MMAP_LOTSAMISS)
+ return;
+
+ /*
+ * mmap read-around
+ */
+ ra_pages = max_sane_readahead(ra->ra_pages);
+ if (ra_pages) {
+ ra->start = max_t(long, 0, offset - ra_pages/2);
+ ra->size = ra_pages;
+ ra->async_size = 0;
+ ra_submit(ra, mapping, file);
+ }
+}
+
+/*
+ * Asynchronous readahead happens when we find the page and PG_readahead,
+ * so we want to possibly extend the readahead further..
+ */
+static void do_async_mmap_readahead(struct vm_area_struct *vma,
+ struct file_ra_state *ra,
+ struct file *file,
+ struct page *page,
+ pgoff_t offset)
+{
+ struct address_space *mapping = file->f_mapping;
+
+ /* If we don't want any read-ahead, don't bother */
+ if (VM_RandomReadHint(vma))
+ return;
+ if (ra->mmap_miss > 0)
+ ra->mmap_miss--;
+ if (PageReadahead(page))
+ page_cache_async_readahead(mapping, ra, file,
+ page, offset, ra->ra_pages);
+}
+
/**
* filemap_fault - read in file data for page fault handling
* @vma: vma in which the fault was taken
struct address_space *mapping = file->f_mapping;
struct file_ra_state *ra = &file->f_ra;
struct inode *inode = mapping->host;
+ pgoff_t offset = vmf->pgoff;
struct page *page;
pgoff_t size;
- int did_readaround = 0;
int ret = 0;
size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- if (vmf->pgoff >= size)
+ if (offset >= size)
return VM_FAULT_SIGBUS;
- /* If we don't want any read-ahead, don't bother */
- if (VM_RandomReadHint(vma))
- goto no_cached_page;
-
/*
* Do we have something in the page cache already?
*/
-retry_find:
- page = find_lock_page(mapping, vmf->pgoff);
- /*
- * For sequential accesses, we use the generic readahead logic.
- */
- if (VM_SequentialReadHint(vma)) {
- if (!page) {
- page_cache_sync_readahead(mapping, ra, file,
- vmf->pgoff, 1);
- page = find_lock_page(mapping, vmf->pgoff);
- if (!page)
- goto no_cached_page;
- }
- if (PageReadahead(page)) {
- page_cache_async_readahead(mapping, ra, file, page,
- vmf->pgoff, 1);
- }
- }
-
- if (!page) {
- unsigned long ra_pages;
-
- ra->mmap_miss++;
-
+ page = find_get_page(mapping, offset);
+ if (likely(page)) {
/*
- * Do we miss much more than hit in this file? If so,
- * stop bothering with read-ahead. It will only hurt.
+ * We found the page, so try async readahead before
+ * waiting for the lock.
*/
- if (ra->mmap_miss > MMAP_LOTSAMISS)
- goto no_cached_page;
+ do_async_mmap_readahead(vma, ra, file, page, offset);
+ lock_page(page);
- /*
- * To keep the pgmajfault counter straight, we need to
- * check did_readaround, as this is an inner loop.
- */
- if (!did_readaround) {
- ret = VM_FAULT_MAJOR;
- count_vm_event(PGMAJFAULT);
- }
- did_readaround = 1;
- ra_pages = max_sane_readahead(file->f_ra.ra_pages);
- if (ra_pages) {
- pgoff_t start = 0;
-
- if (vmf->pgoff > ra_pages / 2)
- start = vmf->pgoff - ra_pages / 2;
- do_page_cache_readahead(mapping, file, start, ra_pages);
+ /* Did it get truncated? */
+ if (unlikely(page->mapping != mapping)) {
+ unlock_page(page);
+ put_page(page);
+ goto no_cached_page;
}
- page = find_lock_page(mapping, vmf->pgoff);
+ } else {
+ /* No page in the page cache at all */
+ do_sync_mmap_readahead(vma, ra, file, offset);
+ count_vm_event(PGMAJFAULT);
+ ret = VM_FAULT_MAJOR;
+retry_find:
+ page = find_lock_page(mapping, offset);
if (!page)
goto no_cached_page;
}
- if (!did_readaround)
- ra->mmap_miss--;
-
/*
* We have a locked page in the page cache, now we need to check
* that it's up-to-date. If not, it is going to be due to an error.
if (unlikely(!PageUptodate(page)))
goto page_not_uptodate;
- /* Must recheck i_size under page lock */
+ /*
+ * Found the page and have a reference on it.
+ * We must recheck i_size under page lock.
+ */
size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- if (unlikely(vmf->pgoff >= size)) {
+ if (unlikely(offset >= size)) {
unlock_page(page);
page_cache_release(page);
return VM_FAULT_SIGBUS;
}
- /*
- * Found the page and have a reference on it.
- */
- mark_page_accessed(page);
- ra->prev_pos = (loff_t)page->index << PAGE_CACHE_SHIFT;
+ ra->prev_pos = (loff_t)offset << PAGE_CACHE_SHIFT;
vmf->page = page;
return ret | VM_FAULT_LOCKED;
* We're only likely to ever get here if MADV_RANDOM is in
* effect.
*/
- error = page_cache_read(file, vmf->pgoff);
+ error = page_cache_read(file, offset);
/*
* The page we want has now been added to the page cache.
return VM_FAULT_SIGBUS;
page_not_uptodate:
- /* IO error path */
- if (!did_readaround) {
- ret = VM_FAULT_MAJOR;
- count_vm_event(PGMAJFAULT);
- }
-
/*
* Umm, take care of errors if the page isn't up-to-date.
* Try to re-read it _once_. We do this synchronously,
}
EXPORT_SYMBOL(filemap_fault);
-struct vm_operations_struct generic_file_vm_ops = {
+const struct vm_operations_struct generic_file_vm_ops = {
.fault = filemap_fault,
};
static struct page *__read_cache_page(struct address_space *mapping,
pgoff_t index,
int (*filler)(void *,struct page*),
- void *data)
+ void *data,
+ gfp_t gfp)
{
struct page *page;
int err;
repeat:
page = find_get_page(mapping, index);
if (!page) {
- page = page_cache_alloc_cold(mapping);
+ page = __page_cache_alloc(gfp | __GFP_COLD);
if (!page)
return ERR_PTR(-ENOMEM);
err = add_to_page_cache_lru(page, mapping, index, GFP_KERNEL);
return page;
}
-/**
- * read_cache_page_async - 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
- *
- * Same as read_cache_page, but don't wait for page to become unlocked
- * after submitting it to the filler.
- *
- * Read into the page cache. If a page already exists, and PageUptodate() is
- * not set, try to fill the page but don't wait for it to become unlocked.
- *
- * If the page does not get brought uptodate, return -EIO.
- */
-struct page *read_cache_page_async(struct address_space *mapping,
+static struct page *do_read_cache_page(struct address_space *mapping,
pgoff_t index,
int (*filler)(void *,struct page*),
- void *data)
+ void *data,
+ gfp_t gfp)
+
{
struct page *page;
int err;
retry:
- page = __read_cache_page(mapping, index, filler, data);
+ page = __read_cache_page(mapping, index, filler, data, gfp);
if (IS_ERR(page))
return page;
if (PageUptodate(page))
mark_page_accessed(page);
return page;
}
+
+/**
+ * read_cache_page_async - 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
+ *
+ * Same as read_cache_page, but don't wait for page to become unlocked
+ * after submitting it to the filler.
+ *
+ * Read into the page cache. If a page already exists, and PageUptodate() is
+ * not set, try to fill the page but don't wait for it to become unlocked.
+ *
+ * If the page does not get brought uptodate, return -EIO.
+ */
+struct page *read_cache_page_async(struct address_space *mapping,
+ pgoff_t index,
+ int (*filler)(void *,struct page*),
+ void *data)
+{
+ return do_read_cache_page(mapping, index, filler, data, mapping_gfp_mask(mapping));
+}
EXPORT_SYMBOL(read_cache_page_async);
+static struct page *wait_on_page_read(struct page *page)
+{
+ if (!IS_ERR(page)) {
+ wait_on_page_locked(page);
+ if (!PageUptodate(page)) {
+ page_cache_release(page);
+ page = ERR_PTR(-EIO);
+ }
+ }
+ return page;
+}
+
+/**
+ * read_cache_page_gfp - read into page cache, using specified page allocation flags.
+ * @mapping: the page's address_space
+ * @index: the page index
+ * @gfp: the page allocator flags to use if allocating
+ *
+ * This is the same as "read_mapping_page(mapping, index, NULL)", but with
+ * any new page allocations done using the specified allocation flags. Note
+ * that the Radix tree operations will still use GFP_KERNEL, so you can't
+ * expect to do this atomically or anything like that - but you can pass in
+ * other page requirements.
+ *
+ * If the page does not get brought uptodate, return -EIO.
+ */
+struct page *read_cache_page_gfp(struct address_space *mapping,
+ pgoff_t index,
+ gfp_t gfp)
+{
+ filler_t *filler = (filler_t *)mapping->a_ops->readpage;
+
+ return wait_on_page_read(do_read_cache_page(mapping, index, filler, NULL, gfp));
+}
+EXPORT_SYMBOL(read_cache_page_gfp);
+
/**
* read_cache_page - read into page cache, fill it if needed
* @mapping: the page's address_space
int (*filler)(void *,struct page*),
void *data)
{
- struct page *page;
-
- page = read_cache_page_async(mapping, index, filler, data);
- if (IS_ERR(page))
- goto out;
- wait_on_page_locked(page);
- if (!PageUptodate(page)) {
- page_cache_release(page);
- page = ERR_PTR(-EIO);
- }
- out:
- return page;
+ return wait_on_page_read(read_cache_page_async(mapping, index, filler, data));
}
EXPORT_SYMBOL(read_cache_page);
if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
kill |= ATTR_KILL_SGID;
- if (unlikely(kill && !capable(CAP_FSETID)))
+ if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode)))
return kill;
return 0;
int copy = min(bytes, iov->iov_len - base);
base = 0;
- left = __copy_from_user_inatomic_nocache(vaddr, buf, copy);
+ left = __copy_from_user_inatomic(vaddr, buf, copy);
copied += copy;
bytes -= copy;
vaddr += copy;
/*
* Copy as much as we can into the page and return the number of bytes which
- * were sucessfully copied. If a fault is encountered then return the number of
+ * were successfully copied. If a fault is encountered then return the number of
* bytes which were copied.
*/
size_t iov_iter_copy_from_user_atomic(struct page *page,
if (likely(i->nr_segs == 1)) {
int left;
char __user *buf = i->iov->iov_base + i->iov_offset;
- left = __copy_from_user_inatomic_nocache(kaddr + offset,
- buf, bytes);
+ left = __copy_from_user_inatomic(kaddr + offset, buf, bytes);
copied = bytes - left;
} else {
copied = __iovec_copy_from_user_inatomic(kaddr + offset,
if (likely(i->nr_segs == 1)) {
int left;
char __user *buf = i->iov->iov_base + i->iov_offset;
- left = __copy_from_user_nocache(kaddr + offset, buf, bytes);
+ left = __copy_from_user(kaddr + offset, buf, bytes);
copied = bytes - left;
} else {
copied = __iovec_copy_from_user_inatomic(kaddr + offset,
inline int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk)
{
struct inode *inode = file->f_mapping->host;
- unsigned long limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
+ unsigned long limit = rlimit(RLIMIT_FSIZE);
if (unlikely(*pos < 0))
return -EINVAL;
{
const struct address_space_operations *aops = mapping->a_ops;
- if (aops->write_begin) {
- return aops->write_begin(file, mapping, pos, len, flags,
+ return aops->write_begin(file, mapping, pos, len, flags,
pagep, fsdata);
- } else {
- int ret;
- pgoff_t index = pos >> PAGE_CACHE_SHIFT;
- unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
- struct inode *inode = mapping->host;
- struct page *page;
-again:
- page = __grab_cache_page(mapping, index);
- *pagep = page;
- if (!page)
- return -ENOMEM;
-
- if (flags & AOP_FLAG_UNINTERRUPTIBLE && !PageUptodate(page)) {
- /*
- * There is no way to resolve a short write situation
- * for a !Uptodate page (except by double copying in
- * the caller done by generic_perform_write_2copy).
- *
- * Instead, we have to bring it uptodate here.
- */
- ret = aops->readpage(file, page);
- page_cache_release(page);
- if (ret) {
- if (ret == AOP_TRUNCATED_PAGE)
- goto again;
- return ret;
- }
- goto again;
- }
-
- ret = aops->prepare_write(file, page, offset, offset+len);
- if (ret) {
- unlock_page(page);
- page_cache_release(page);
- if (pos + len > inode->i_size)
- vmtruncate(inode, inode->i_size);
- }
- return ret;
- }
}
EXPORT_SYMBOL(pagecache_write_begin);
struct page *page, void *fsdata)
{
const struct address_space_operations *aops = mapping->a_ops;
- int ret;
-
- if (aops->write_end) {
- mark_page_accessed(page);
- ret = aops->write_end(file, mapping, pos, len, copied,
- page, fsdata);
- } else {
- unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
- struct inode *inode = mapping->host;
-
- flush_dcache_page(page);
- ret = aops->commit_write(file, page, offset, offset+len);
- unlock_page(page);
- mark_page_accessed(page);
- page_cache_release(page);
-
- if (ret < 0) {
- if (pos + len > inode->i_size)
- vmtruncate(inode, inode->i_size);
- } else if (ret > 0)
- ret = min_t(size_t, copied, ret);
- else
- ret = copied;
- }
- return ret;
+ mark_page_accessed(page);
+ return aops->write_end(file, mapping, pos, len, copied, page, fsdata);
}
EXPORT_SYMBOL(pagecache_write_end);
if (count != ocount)
*nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count);
- /*
- * 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);
+ written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1);
if (written)
goto out;
}
*ppos = end;
}
-
- /*
- * 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_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 (err < 0)
- written = err;
- }
return written;
}
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.
*/
-struct page *__grab_cache_page(struct address_space *mapping, pgoff_t index)
+struct page *grab_cache_page_write_begin(struct address_space *mapping,
+ pgoff_t index, unsigned flags)
{
int status;
struct page *page;
+ gfp_t gfp_notmask = 0;
+ if (flags & AOP_FLAG_NOFS)
+ gfp_notmask = __GFP_FS;
repeat:
page = find_lock_page(mapping, index);
if (likely(page))
return page;
- page = page_cache_alloc(mapping);
+ page = __page_cache_alloc(mapping_gfp_mask(mapping) & ~gfp_notmask);
if (!page)
return NULL;
- status = add_to_page_cache_lru(page, mapping, index, GFP_KERNEL);
+ status = add_to_page_cache_lru(page, mapping, index,
+ GFP_KERNEL & ~gfp_notmask);
if (unlikely(status)) {
page_cache_release(page);
if (status == -EEXIST)
}
return page;
}
-EXPORT_SYMBOL(__grab_cache_page);
-
-static ssize_t generic_perform_write_2copy(struct file *file,
- struct iov_iter *i, loff_t pos)
-{
- struct address_space *mapping = file->f_mapping;
- const struct address_space_operations *a_ops = mapping->a_ops;
- struct inode *inode = mapping->host;
- long status = 0;
- ssize_t written = 0;
-
- do {
- struct page *src_page;
- struct page *page;
- pgoff_t index; /* Pagecache index for current page */
- unsigned long offset; /* Offset into pagecache page */
- unsigned long bytes; /* Bytes to write to page */
- size_t copied; /* Bytes copied from user */
-
- offset = (pos & (PAGE_CACHE_SIZE - 1));
- index = pos >> PAGE_CACHE_SHIFT;
- bytes = min_t(unsigned long, PAGE_CACHE_SIZE - offset,
- iov_iter_count(i));
-
- /*
- * a non-NULL src_page indicates that we're doing the
- * copy via get_user_pages and kmap.
- */
- src_page = NULL;
-
- /*
- * Bring in the user page that we will copy from _first_.
- * Otherwise there's a nasty deadlock on copying from the
- * same page as we're writing to, without it being marked
- * up-to-date.
- *
- * Not only is this an optimisation, but it is also required
- * to check that the address is actually valid, when atomic
- * usercopies are used, below.
- */
- if (unlikely(iov_iter_fault_in_readable(i, bytes))) {
- status = -EFAULT;
- break;
- }
-
- page = __grab_cache_page(mapping, index);
- if (!page) {
- status = -ENOMEM;
- break;
- }
-
- /*
- * non-uptodate pages cannot cope with short copies, and we
- * cannot take a pagefault with the destination page locked.
- * So pin the source page to copy it.
- */
- if (!PageUptodate(page) && !segment_eq(get_fs(), KERNEL_DS)) {
- unlock_page(page);
-
- src_page = alloc_page(GFP_KERNEL);
- if (!src_page) {
- page_cache_release(page);
- status = -ENOMEM;
- break;
- }
-
- /*
- * Cannot get_user_pages with a page locked for the
- * same reason as we can't take a page fault with a
- * page locked (as explained below).
- */
- copied = iov_iter_copy_from_user(src_page, i,
- offset, bytes);
- if (unlikely(copied == 0)) {
- status = -EFAULT;
- page_cache_release(page);
- page_cache_release(src_page);
- break;
- }
- bytes = copied;
-
- lock_page(page);
- /*
- * Can't handle the page going uptodate here, because
- * that means we would use non-atomic usercopies, which
- * zero out the tail of the page, which can cause
- * zeroes to become transiently visible. We could just
- * use a non-zeroing copy, but the APIs aren't too
- * consistent.
- */
- if (unlikely(!page->mapping || PageUptodate(page))) {
- unlock_page(page);
- page_cache_release(page);
- page_cache_release(src_page);
- continue;
- }
- }
-
- status = a_ops->prepare_write(file, page, offset, offset+bytes);
- if (unlikely(status))
- goto fs_write_aop_error;
-
- if (!src_page) {
- /*
- * Must not enter the pagefault handler here, because
- * we hold the page lock, so we might recursively
- * deadlock on the same lock, or get an ABBA deadlock
- * against a different lock, or against the mmap_sem
- * (which nests outside the page lock). So increment
- * preempt count, and use _atomic usercopies.
- *
- * The page is uptodate so we are OK to encounter a
- * short copy: if unmodified parts of the page are
- * marked dirty and written out to disk, it doesn't
- * really matter.
- */
- pagefault_disable();
- copied = iov_iter_copy_from_user_atomic(page, i,
- offset, bytes);
- pagefault_enable();
- } else {
- void *src, *dst;
- src = kmap_atomic(src_page, KM_USER0);
- dst = kmap_atomic(page, KM_USER1);
- memcpy(dst + offset, src + offset, bytes);
- kunmap_atomic(dst, KM_USER1);
- kunmap_atomic(src, KM_USER0);
- copied = bytes;
- }
- flush_dcache_page(page);
-
- status = a_ops->commit_write(file, page, offset, offset+bytes);
- if (unlikely(status < 0))
- goto fs_write_aop_error;
- if (unlikely(status > 0)) /* filesystem did partial write */
- copied = min_t(size_t, copied, status);
-
- unlock_page(page);
- mark_page_accessed(page);
- page_cache_release(page);
- if (src_page)
- page_cache_release(src_page);
-
- iov_iter_advance(i, copied);
- pos += copied;
- written += copied;
-
- balance_dirty_pages_ratelimited(mapping);
- cond_resched();
- continue;
-
-fs_write_aop_error:
- unlock_page(page);
- page_cache_release(page);
- if (src_page)
- page_cache_release(src_page);
-
- /*
- * prepare_write() may have instantiated a few blocks
- * outside i_size. Trim these off again. Don't need
- * i_size_read because we hold i_mutex.
- */
- if (pos + bytes > inode->i_size)
- vmtruncate(inode, inode->i_size);
- break;
- } while (iov_iter_count(i));
-
- return written ? written : status;
-}
+EXPORT_SYMBOL(grab_cache_page_write_begin);
static ssize_t generic_perform_write(struct file *file,
struct iov_iter *i, loff_t pos)
if (unlikely(status))
break;
+ if (mapping_writably_mapped(mapping))
+ flush_dcache_page(page);
+
pagefault_disable();
copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes);
pagefault_enable();
flush_dcache_page(page);
+ mark_page_accessed(page);
status = a_ops->write_end(file, mapping, pos, bytes, copied,
page, fsdata);
if (unlikely(status < 0))
size_t count, ssize_t written)
{
struct file *file = iocb->ki_filp;
- struct address_space *mapping = file->f_mapping;
- const struct address_space_operations *a_ops = mapping->a_ops;
- struct inode *inode = mapping->host;
ssize_t status;
struct iov_iter i;
iov_iter_init(&i, iov, nr_segs, count, written);
- if (a_ops->write_begin)
- status = generic_perform_write(file, &i, pos);
- else
- status = generic_perform_write_2copy(file, &i, pos);
+ status = generic_perform_write(file, &i, pos);
if (likely(status >= 0)) {
written += status;
*ppos = pos + status;
-
- /*
- * For now, when the user asks for O_SYNC, we'll actually give
- * O_DSYNC
- */
- if (unlikely((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
- if (!a_ops->writepage || !is_sync_kiocb(iocb))
- status = generic_osync_inode(inode, mapping,
- OSYNC_METADATA|OSYNC_DATA);
- }
}
- /*
- * If we get here for O_DIRECT writes then we must have fallen through
- * to buffered writes (block instantiation inside i_size). So we sync
- * the file data here, to try to honour O_DIRECT expectations.
- */
- if (unlikely(file->f_flags & O_DIRECT) && written)
- status = filemap_write_and_wait(mapping);
-
return written ? written : status;
}
EXPORT_SYMBOL(generic_file_buffered_write);
-static ssize_t
-__generic_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t *ppos)
+/**
+ * __generic_file_aio_write - write data to a file
+ * @iocb: IO state structure (file, offset, etc.)
+ * @iov: vector with data to write
+ * @nr_segs: number of segments in the vector
+ * @ppos: position where to write
+ *
+ * This function does all the work needed for actually writing data to a
+ * file. It does all basic checks, removes SUID from the file, updates
+ * modification times and calls proper subroutines depending on whether we
+ * do direct IO or a standard buffered write.
+ *
+ * It expects i_mutex to be grabbed unless we work on a block device or similar
+ * object which does not need locking at all.
+ *
+ * This function does *not* take care of syncing data in case of O_SYNC write.
+ * A caller has to handle it. This is mainly due to the fact that we want to
+ * avoid syncing under i_mutex.
+ */
+ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t *ppos)
{
struct file *file = iocb->ki_filp;
struct address_space * mapping = file->f_mapping;
* semantics.
*/
endbyte = pos + written_buffered - written - 1;
- err = do_sync_mapping_range(file->f_mapping, pos, endbyte,
- SYNC_FILE_RANGE_WAIT_BEFORE|
- SYNC_FILE_RANGE_WRITE|
- SYNC_FILE_RANGE_WAIT_AFTER);
+ err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
if (err == 0) {
written = written_buffered;
invalidate_mapping_pages(mapping,
current->backing_dev_info = NULL;
return written ? written : err;
}
+EXPORT_SYMBOL(__generic_file_aio_write);
-ssize_t generic_file_aio_write_nolock(struct kiocb *iocb,
- const struct iovec *iov, unsigned long nr_segs, loff_t pos)
-{
- struct file *file = iocb->ki_filp;
- struct address_space *mapping = file->f_mapping;
- struct inode *inode = mapping->host;
- ssize_t ret;
-
- BUG_ON(iocb->ki_pos != pos);
-
- ret = __generic_file_aio_write_nolock(iocb, iov, nr_segs,
- &iocb->ki_pos);
-
- if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
- ssize_t err;
-
- err = sync_page_range_nolock(inode, mapping, pos, ret);
- if (err < 0)
- ret = err;
- }
- return ret;
-}
-EXPORT_SYMBOL(generic_file_aio_write_nolock);
-
+/**
+ * generic_file_aio_write - write data to a file
+ * @iocb: IO state structure
+ * @iov: vector with data to write
+ * @nr_segs: number of segments in the vector
+ * @pos: position in file where to write
+ *
+ * This is a wrapper around __generic_file_aio_write() to be used by most
+ * filesystems. It takes care of syncing the file in case of O_SYNC file
+ * and acquires i_mutex as needed.
+ */
ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
struct file *file = iocb->ki_filp;
- struct address_space *mapping = file->f_mapping;
- struct inode *inode = mapping->host;
+ struct inode *inode = file->f_mapping->host;
ssize_t ret;
BUG_ON(iocb->ki_pos != pos);
mutex_lock(&inode->i_mutex);
- ret = __generic_file_aio_write_nolock(iocb, iov, nr_segs,
- &iocb->ki_pos);
+ ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
mutex_unlock(&inode->i_mutex);
- if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
+ if (ret > 0 || ret == -EIOCBQUEUED) {
ssize_t err;
- err = sync_page_range(inode, mapping, pos, ret);
- if (err < 0)
+ err = generic_write_sync(file, pos, ret);
+ if (err < 0 && ret > 0)
ret = err;
}
return ret;
* (presumably at page->private). If the release was successful, return `1'.
* Otherwise return zero.
*
+ * This may also be called if PG_fscache is set on a page, indicating that the
+ * page is known to the local caching routines.
+ *
* 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 & __GFP_FS).
*
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff