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>
This commit is contained in:
Feng Shuo 2013-01-15 11:23:28 +08:00 committed by Miklos Szeredi
parent c2132c1bc7
commit 4582a4ab2a
3 changed files with 38 additions and 3 deletions

View File

@ -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 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
attr_version);
fuse_change_entry_timeout(entry, &outarg);
}
fuse_advise_use_readdirplus(inode);
return 1;
}
@ -355,6 +377,7 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
else
fuse_invalidate_entry_cache(entry);
fuse_advise_use_readdirplus(dir);
return newent;
out_iput:
@ -1290,7 +1313,7 @@ static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file,
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 @@ static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
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 @@ static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
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);

View File

@ -106,6 +106,15 @@ struct fuse_inode {
/** 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;

View File

@ -92,6 +92,7 @@ static struct inode *fuse_alloc_inode(struct super_block *sb)
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);