* 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>
/*
* 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
*/
/*
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));
/*
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;
}
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;
/*
* 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 active_anon lru below, and mem_cgroup_cache_charge
+ * 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))
if (page_is_file_cache(page))
lru_cache_add_file(page);
else
- lru_cache_add_active_anon(page);
+ lru_cache_add_anon(page);
}
return ret;
}
#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);
}
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);
if (VM_RandomReadHint(vma))
return;
- if (VM_SequentialReadHint(vma)) {
- page_cache_sync_readahead(mapping, ra, file, offset, 1);
+ 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 > MMAP_LOTSAMISS)
return;
+ /*
+ * mmap read-around
+ */
ra_pages = max_sane_readahead(ra->ra_pages);
if (ra_pages) {
- pgoff_t start = 0;
-
- if (offset > ra_pages / 2)
- start = offset - ra_pages / 2;
- do_page_cache_readahead(mapping, file, start, 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);
}
}
if (ra->mmap_miss > 0)
ra->mmap_miss--;
if (PageReadahead(page))
- page_cache_async_readahead(mapping, ra, file, page, offset, 1);
+ page_cache_async_readahead(mapping, ra, file,
+ page, offset, ra->ra_pages);
}
/**
}
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);
/*
* 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,
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;
}
*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);
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;
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_range(mapping,
- pos, pos + written - 1);
-
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;
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff