FUSE: Adapt readdirplus to application usage patterns
Use the same adaptive readdirplus mechanism as NFS:
http://permalink.gmane.org/gmane.linux.nfs/49299
If the user space implementation wants to disable readdirplus
temporarily, it could just return ENOTSUPP. Then kernel will
recall it with readdir.
Signed-off-by: Feng Shuo <steve.shuo.feng@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index aa0b6ad..dc5e648 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -14,6 +14,27 @@
#include <linux/namei.h>
#include <linux/slab.h>
+static bool fuse_use_readdirplus(struct inode *dir, struct file *filp)
+{
+ struct fuse_conn *fc = get_fuse_conn(dir);
+ struct fuse_inode *fi = get_fuse_inode(dir);
+
+ if (!fc->do_readdirplus)
+ return false;
+ if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state))
+ return true;
+ if (filp->f_pos == 0)
+ return true;
+ return false;
+}
+
+static void fuse_advise_use_readdirplus(struct inode *dir)
+{
+ struct fuse_inode *fi = get_fuse_inode(dir);
+
+ set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state);
+}
+
#if BITS_PER_LONG >= 64
static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
{
@@ -219,6 +240,7 @@
attr_version);
fuse_change_entry_timeout(entry, &outarg);
}
+ fuse_advise_use_readdirplus(inode);
return 1;
}
@@ -355,6 +377,7 @@
else
fuse_invalidate_entry_cache(entry);
+ fuse_advise_use_readdirplus(dir);
return newent;
out_iput:
@@ -1290,7 +1313,7 @@
static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
{
- int err;
+ int plus, err;
size_t nbytes;
struct page *page;
struct inode *inode = file->f_path.dentry->d_inode;
@@ -1310,11 +1333,13 @@
fuse_put_request(fc, req);
return -ENOMEM;
}
+
+ plus = fuse_use_readdirplus(inode, file);
req->out.argpages = 1;
req->num_pages = 1;
req->pages[0] = page;
req->page_descs[0].length = PAGE_SIZE;
- if (fc->do_readdirplus) {
+ if (plus) {
attr_version = fuse_get_attr_version(fc);
fuse_read_fill(req, file, file->f_pos, PAGE_SIZE,
FUSE_READDIRPLUS);
@@ -1327,7 +1352,7 @@
err = req->out.h.error;
fuse_put_request(fc, req);
if (!err) {
- if (fc->do_readdirplus) {
+ if (plus) {
err = parse_dirplusfile(page_address(page), nbytes,
file, dstbuf, filldir,
attr_version);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index af51c14..fc55dd3 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -106,6 +106,15 @@
/** List of writepage requestst (pending or sent) */
struct list_head writepages;
+
+ /** Miscellaneous bits describing inode state */
+ unsigned long state;
+};
+
+/** FUSE inode state bits */
+enum {
+ /** Advise readdirplus */
+ FUSE_I_ADVISE_RDPLUS,
};
struct fuse_conn;
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 79b70de..9876a87 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -92,6 +92,7 @@
fi->attr_version = 0;
fi->writectr = 0;
fi->orig_ino = 0;
+ fi->state = 0;
INIT_LIST_HEAD(&fi->write_files);
INIT_LIST_HEAD(&fi->queued_writes);
INIT_LIST_HEAD(&fi->writepages);
