e1f8e87449
People can use the real name an an index into MAINTAINERS to find the current email address. Signed-off-by: Francois Cami <francois.cami@free.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
138 lines
2.9 KiB
C
138 lines
2.9 KiB
C
/*
|
|
* mm/fadvise.c
|
|
*
|
|
* Copyright (C) 2002, Linus Torvalds
|
|
*
|
|
* 11Jan2003 Andrew Morton
|
|
* Initial version.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/file.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/backing-dev.h>
|
|
#include <linux/pagevec.h>
|
|
#include <linux/fadvise.h>
|
|
#include <linux/writeback.h>
|
|
#include <linux/syscalls.h>
|
|
|
|
#include <asm/unistd.h>
|
|
|
|
/*
|
|
* POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could
|
|
* deactivate the pages and clear PG_Referenced.
|
|
*/
|
|
asmlinkage long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
|
|
{
|
|
struct file *file = fget(fd);
|
|
struct address_space *mapping;
|
|
struct backing_dev_info *bdi;
|
|
loff_t endbyte; /* inclusive */
|
|
pgoff_t start_index;
|
|
pgoff_t end_index;
|
|
unsigned long nrpages;
|
|
int ret = 0;
|
|
|
|
if (!file)
|
|
return -EBADF;
|
|
|
|
if (S_ISFIFO(file->f_path.dentry->d_inode->i_mode)) {
|
|
ret = -ESPIPE;
|
|
goto out;
|
|
}
|
|
|
|
mapping = file->f_mapping;
|
|
if (!mapping || len < 0) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (mapping->a_ops->get_xip_mem) {
|
|
switch (advice) {
|
|
case POSIX_FADV_NORMAL:
|
|
case POSIX_FADV_RANDOM:
|
|
case POSIX_FADV_SEQUENTIAL:
|
|
case POSIX_FADV_WILLNEED:
|
|
case POSIX_FADV_NOREUSE:
|
|
case POSIX_FADV_DONTNEED:
|
|
/* no bad return value, but ignore advice */
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
/* Careful about overflows. Len == 0 means "as much as possible" */
|
|
endbyte = offset + len;
|
|
if (!len || endbyte < len)
|
|
endbyte = -1;
|
|
else
|
|
endbyte--; /* inclusive */
|
|
|
|
bdi = mapping->backing_dev_info;
|
|
|
|
switch (advice) {
|
|
case POSIX_FADV_NORMAL:
|
|
file->f_ra.ra_pages = bdi->ra_pages;
|
|
break;
|
|
case POSIX_FADV_RANDOM:
|
|
file->f_ra.ra_pages = 0;
|
|
break;
|
|
case POSIX_FADV_SEQUENTIAL:
|
|
file->f_ra.ra_pages = bdi->ra_pages * 2;
|
|
break;
|
|
case POSIX_FADV_WILLNEED:
|
|
if (!mapping->a_ops->readpage) {
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
/* First and last PARTIAL page! */
|
|
start_index = offset >> PAGE_CACHE_SHIFT;
|
|
end_index = endbyte >> PAGE_CACHE_SHIFT;
|
|
|
|
/* Careful about overflow on the "+1" */
|
|
nrpages = end_index - start_index + 1;
|
|
if (!nrpages)
|
|
nrpages = ~0UL;
|
|
|
|
ret = force_page_cache_readahead(mapping, file,
|
|
start_index,
|
|
max_sane_readahead(nrpages));
|
|
if (ret > 0)
|
|
ret = 0;
|
|
break;
|
|
case POSIX_FADV_NOREUSE:
|
|
break;
|
|
case POSIX_FADV_DONTNEED:
|
|
if (!bdi_write_congested(mapping->backing_dev_info))
|
|
filemap_flush(mapping);
|
|
|
|
/* First and last FULL page! */
|
|
start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
|
|
end_index = (endbyte >> PAGE_CACHE_SHIFT);
|
|
|
|
if (end_index >= start_index)
|
|
invalidate_mapping_pages(mapping, start_index,
|
|
end_index);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
}
|
|
out:
|
|
fput(file);
|
|
return ret;
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_SYS_FADVISE64
|
|
|
|
asmlinkage long sys_fadvise64(int fd, loff_t offset, size_t len, int advice)
|
|
{
|
|
return sys_fadvise64_64(fd, offset, len, advice);
|
|
}
|
|
|
|
#endif
|