Add metadata readahead ioctl.
Signed-off-by: Shaohua Li <shaohua...@intel.com>
---
fs/btrfs/disk-io.c | 10 ++++++++++
fs/btrfs/ioctl.c | 23 +++++++++++++++++++++++
fs/btrfs/ioctl.h | 7 +++++++
mm/readahead.c | 1 +
4 files changed, 41 insertions(+)
Index: linux/mm/readahead.c
===================================================================
--- linux.orig/mm/readahead.c 2010-07-14 10:13:55.000000000 +0800
+++ linux/mm/readahead.c 2010-07-14 10:14:47.000000000 +0800
@@ -228,6 +228,7 @@ int force_page_cache_readahead(struct ad
}
return ret;
}
+EXPORT_SYMBOL_GPL(force_page_cache_readahead);
/*
* Given a desired number of PAGE_CACHE_SIZE readahead pages, return a
Index: linux/fs/btrfs/disk-io.c
===================================================================
--- linux.orig/fs/btrfs/disk-io.c 2010-07-14 10:17:39.000000000 +0800
+++ linux/fs/btrfs/disk-io.c 2010-07-14 10:22:33.000000000 +0800
@@ -746,6 +746,15 @@ static int btree_readpage(struct file *f
return extent_read_full_page(tree, page, btree_get_extent);
}
+static int btree_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(mapping->host)->io_tree;
+ return extent_readpages(tree, mapping, pages, nr_pages,
+ btree_get_extent);
+}
+
static int btree_releasepage(struct page *page, gfp_t gfp_flags)
{
struct extent_io_tree *tree;
@@ -789,6 +798,7 @@ static void btree_invalidatepage(struct
static const struct address_space_operations btree_aops = {
.readpage = btree_readpage,
+ .readpages = btree_readpages,
.writepage = btree_writepage,
.writepages = btree_writepages,
.releasepage = btree_releasepage,
Index: linux/fs/btrfs/ioctl.c
===================================================================
--- linux.orig/fs/btrfs/ioctl.c 2010-07-14 10:15:55.000000000 +0800
+++ linux/fs/btrfs/ioctl.c 2010-07-14 10:17:25.000000000 +0800
@@ -2077,6 +2077,27 @@ static long btrfs_ioctl_meta_incore(stru
return entries;
}
+static long btrfs_ioctl_meta_readahead(struct btrfs_root *root,
+ void __user *argp)
+{
+ struct inode *btree_inode = root->fs_info->btree_inode;
+ struct address_space *mapping = btree_inode->i_mapping;
+ struct btrfs_ioctl_meta_readahead_args args;
+ pgoff_t index;
+ unsigned long nr_to_read;
+
+ if (copy_from_user(&args,
+ (struct btrfs_ioctl_meta_readahead_args __user *)argp, sizeof(args)))
+ return -EFAULT;
+
+ index = args.offset >> PAGE_CACHE_SHIFT;
+ nr_to_read = (args.offset + args.size - 1) >> PAGE_CACHE_SHIFT;
+ nr_to_read = nr_to_read - index + 1;
+
+ force_page_cache_readahead(mapping, NULL, index, nr_to_read);
+ return 0;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
@@ -2129,6 +2150,8 @@ long btrfs_ioctl(struct file *file, unsi
return 0;
case BTRFS_IOC_META_INCORE:
return btrfs_ioctl_meta_incore(root, argp);
+ case BTRFS_IOC_META_READAHEAD:
+ return btrfs_ioctl_meta_readahead(root, argp);
}
return -ENOTTY;
Index: linux/fs/btrfs/ioctl.h
===================================================================
--- linux.orig/fs/btrfs/ioctl.h 2010-07-14 10:14:55.000000000 +0800
+++ linux/fs/btrfs/ioctl.h 2010-07-14 10:15:53.000000000 +0800
@@ -151,6 +151,11 @@ struct btrfs_ioctl_meta_incore_args {
__u32 unused;
};
+struct btrfs_ioctl_meta_readahead_args {
+ __u64 offset;
+ __u64 size;
+};
+
#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -193,4 +198,6 @@ struct btrfs_ioctl_meta_incore_args {
struct btrfs_ioctl_space_args)
#define BTRFS_IOC_META_INCORE _IOW(BTRFS_IOCTL_MAGIC, 21, \
struct btrfs_ioctl_meta_incore_args)
+#define BTRFS_IOC_META_READAHEAD _IOW(BTRFS_IOCTL_MAGIC, 22, \
+ struct btrfs_ioctl_meta_readahead_args)
#endif
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