Thanks,
Ying Zhu
Signed-off-by: Ying Zhu <casualfis...@gmail.com>
---
include/linux/fs.h | 1 -
mm/fadvise.c | 2 --
mm/filemap.c | 17 +++++++++++------
mm/readahead.c | 8 ++++----
4 files changed, 15 insertions(+), 13 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 17fd887..36303a5 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -991,7 +991,6 @@ struct file_ra_state {
unsigned int async_size; /* do asynchronous readahead when
there are only # of pages ahead
*/
- unsigned int ra_pages; /* Maximum readahead window */
unsigned int mmap_miss; /* Cache miss stat for mmap
accesses */
loff_t prev_pos; /* Cache last read() position */
};
diff --git a/mm/fadvise.c b/mm/fadvise.c
index 469491e..75e2378 100644
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -76,7 +76,6 @@ SYSCALL_DEFINE(fadvise64_64)(int fd, loff_t offset,
loff_t len, int advice)
switch (advice) {
case POSIX_FADV_NORMAL:
- file->f_ra.ra_pages = bdi->ra_pages;
spin_lock(&file->f_lock);
file->f_mode &= ~FMODE_RANDOM;
spin_unlock(&file->f_lock);
@@ -87,7 +86,6 @@ SYSCALL_DEFINE(fadvise64_64)(int fd, loff_t offset,
loff_t len, int advice)
spin_unlock(&file->f_lock);
break;
case POSIX_FADV_SEQUENTIAL:
- file->f_ra.ra_pages = bdi->ra_pages * 2;
spin_lock(&file->f_lock);
file->f_mode &= ~FMODE_RANDOM;
spin_unlock(&file->f_lock);
diff --git a/mm/filemap.c b/mm/filemap.c
index a4a5260..e7e4409 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1058,11 +1058,15 @@ EXPORT_SYMBOL(grab_cache_page_nowait);
* 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.
+ * It's hard to estimate how the bad sectors lay out, so to be
conservative,
+ * set the read mode in random.
*/
static void shrink_readahead_size_eio(struct file *filp,
struct file_ra_state *ra)
{
- ra->ra_pages /= 4;
+ spin_lock(&filp->f_lock);
+ filp->f_mode |= FMODE_RANDOM;
+ spin_unlock(&filp->f_lock);
}
/**
@@ -1527,12 +1531,12 @@ static void do_sync_mmap_readahead(struct
vm_area_struct *vma,
/* If we don't want any read-ahead, don't bother */
if (VM_RandomReadHint(vma))
return;
- if (!ra->ra_pages)
+ if (!mapping->backing_dev_info->ra_pages)
return;
if (VM_SequentialReadHint(vma)) {
- page_cache_sync_readahead(mapping, ra, file, offset,
- ra->ra_pages);
+ page_cache_sync_readahead(mapping, ra, file, offset,
+
mapping->backing_dev_info->ra_pages);
return;
}
@@ -1550,7 +1554,7 @@ static void do_sync_mmap_readahead(struct
vm_area_struct *vma,
/*
* mmap read-around
*/
- ra_pages = max_sane_readahead(ra->ra_pages);
+ ra_pages =
max_sane_readahead(mapping->backing_dev_info->ra_pages);
ra->start = max_t(long, 0, offset - ra_pages / 2);
ra->size = ra_pages;
ra->async_size = ra_pages / 4;
@@ -1576,7 +1580,8 @@ static void do_async_mmap_readahead(struct
vm_area_struct *vma,
ra->mmap_miss--;
if (PageReadahead(page))
page_cache_async_readahead(mapping, ra, file,
- page, offset, ra->ra_pages);
+ page, offset,
+
mapping->backing_dev_info->ra_pages);
}
/**
diff --git a/mm/readahead.c b/mm/readahead.c
index ea8f8fa..6ea5999 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -27,7 +27,6 @@
void
file_ra_state_init(struct file_ra_state *ra, struct address_space
*mapping)
{
- ra->ra_pages = mapping->backing_dev_info->ra_pages;
ra->prev_pos = -1;
}
EXPORT_SYMBOL_GPL(file_ra_state_init);
@@ -400,7 +399,8 @@ ondemand_readahead(struct address_space *mapping,
bool hit_readahead_marker, pgoff_t offset,
unsigned long req_size)
{
- unsigned long max = max_sane_readahead(ra->ra_pages);
+ struct backing_dev_info *bdi = mapping->backing_dev_info;
+ unsigned long max = max_sane_readahead(bdi->ra_pages);
/*
* start of file
@@ -507,7 +507,7 @@ void page_cache_sync_readahead(struct address_space
*mapping,
pgoff_t offset, unsigned long req_size)
{
/* no read-ahead */
- if (!ra->ra_pages)
+ if (!mapping->backing_dev_info->ra_pages)
return;
/* be dumb */
@@ -543,7 +543,7 @@ page_cache_async_readahead(struct address_space
*mapping,
unsigned long req_size)
{
/* no read-ahead */
- if (!ra->ra_pages)
+ if (!mapping->backing_dev_info->ra_pages)
return;
/*
