Btrfs: Do more optimal file RA during shrinking and defrag
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a589912..fe4fe70 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2263,6 +2263,12 @@
return 0;
}
+static unsigned long calc_ra(unsigned long start, unsigned long last,
+ unsigned long nr)
+{
+ return min(last, start + nr - 1);
+}
+
static int noinline relocate_inode_pages(struct inode *inode, u64 start,
u64 len)
{
@@ -2275,6 +2281,8 @@
struct page *page;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct file_ra_state *ra;
+ unsigned long total_read = 0;
+ unsigned long ra_pages;
ra = kzalloc(sizeof(*ra), GFP_NOFS);
@@ -2282,11 +2290,17 @@
i = start >> PAGE_CACHE_SHIFT;
last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
+ ra_pages = BTRFS_I(inode)->root->fs_info->bdi.ra_pages;
+
file_ra_state_init(ra, inode->i_mapping);
- btrfs_force_ra(inode->i_mapping, ra, NULL, i, last_index);
kfree(ra);
for (; i <= last_index; i++) {
+ if (total_read % ra_pages == 0) {
+ btrfs_force_ra(inode->i_mapping, ra, NULL, i,
+ calc_ra(i, last_index, ra_pages));
+ }
+ total_read++;
page = grab_cache_page(inode->i_mapping, i);
if (!page)
goto out_unlock;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 4d12aa5..ab707c0 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2814,14 +2814,12 @@
struct file_ra_state *ra, struct file *file,
pgoff_t offset, pgoff_t last_index)
{
- pgoff_t req_size;
+ pgoff_t req_size = last_index - offset + 1;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
- req_size = last_index - offset + 1;
offset = page_cache_readahead(mapping, ra, file, offset, req_size);
return offset;
#else
- req_size = min(last_index - offset + 1, (pgoff_t)128);
page_cache_sync_readahead(mapping, ra, file, offset, req_size);
return offset + req_size;
#endif
@@ -2833,7 +2831,8 @@
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct page *page;
unsigned long last_index;
- unsigned long ra_index = 0;
+ unsigned long ra_pages = root->fs_info->bdi.ra_pages;
+ unsigned long total_read = 0;
u64 page_start;
u64 page_end;
unsigned long i;
@@ -2848,11 +2847,11 @@
mutex_lock(&inode->i_mutex);
last_index = inode->i_size >> PAGE_CACHE_SHIFT;
for (i = 0; i <= last_index; i++) {
- if (i == ra_index) {
- ra_index = btrfs_force_ra(inode->i_mapping,
- &file->f_ra,
- file, ra_index, last_index);
+ if (total_read % ra_pages == 0) {
+ btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
+ min(last_index, i + ra_pages - 1));
}
+ total_read++;
page = grab_cache_page(inode->i_mapping, i);
if (!page)
goto out_unlock;