Commit db50b96c authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds
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[PATCH] FUSE - readpages operation



This patch adds readpages support to FUSE.

With the help of the readpages() operation multiple reads are bundled
together and sent as a single request to userspace.  This can improve
reading performace.
Signed-off-by: default avatarMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 06663267
......@@ -227,6 +227,72 @@ static int fuse_readpage(struct file *file, struct page *page)
return err;
}
static int fuse_send_readpages(struct fuse_req *req, struct file *file,
struct inode *inode)
{
loff_t pos = (loff_t) req->pages[0]->index << PAGE_CACHE_SHIFT;
size_t count = req->num_pages << PAGE_CACHE_SHIFT;
unsigned i;
req->out.page_zeroing = 1;
fuse_send_read(req, file, inode, pos, count);
for (i = 0; i < req->num_pages; i++) {
struct page *page = req->pages[i];
if (!req->out.h.error)
SetPageUptodate(page);
unlock_page(page);
}
return req->out.h.error;
}
struct fuse_readpages_data {
struct fuse_req *req;
struct file *file;
struct inode *inode;
};
static int fuse_readpages_fill(void *_data, struct page *page)
{
struct fuse_readpages_data *data = _data;
struct fuse_req *req = data->req;
struct inode *inode = data->inode;
struct fuse_conn *fc = get_fuse_conn(inode);
if (req->num_pages &&
(req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
(req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
req->pages[req->num_pages - 1]->index + 1 != page->index)) {
int err = fuse_send_readpages(req, data->file, inode);
if (err) {
unlock_page(page);
return err;
}
fuse_reset_request(req);
}
req->pages[req->num_pages] = page;
req->num_pages ++;
return 0;
}
static int fuse_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
struct inode *inode = mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_readpages_data data;
int err;
data.file = file;
data.inode = inode;
data.req = fuse_get_request_nonint(fc);
if (!data.req)
return -EINTR;
err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
if (!err && data.req->num_pages)
err = fuse_send_readpages(data.req, file, inode);
fuse_put_request(fc, data.req);
return err;
}
static ssize_t fuse_send_write(struct fuse_req *req, struct file *file,
struct inode *inode, loff_t pos, size_t count)
{
......@@ -331,6 +397,7 @@ static struct address_space_operations fuse_file_aops = {
.readpage = fuse_readpage,
.prepare_write = fuse_prepare_write,
.commit_write = fuse_commit_write,
.readpages = fuse_readpages,
.set_page_dirty = fuse_set_page_dirty,
};
......
......@@ -201,6 +201,9 @@ struct fuse_conn {
/** The fuse mount flags for this mount */
unsigned flags;
/** Maximum read size */
unsigned max_read;
/** Readers of the connection are waiting on this */
wait_queue_head_t waitq;
......
......@@ -32,6 +32,7 @@ struct fuse_mount_data {
unsigned rootmode;
unsigned user_id;
unsigned flags;
unsigned max_read;
};
static struct inode *fuse_alloc_inode(struct super_block *sb)
......@@ -250,6 +251,7 @@ enum {
OPT_DEFAULT_PERMISSIONS,
OPT_ALLOW_OTHER,
OPT_KERNEL_CACHE,
OPT_MAX_READ,
OPT_ERR
};
......@@ -260,6 +262,7 @@ static match_table_t tokens = {
{OPT_DEFAULT_PERMISSIONS, "default_permissions"},
{OPT_ALLOW_OTHER, "allow_other"},
{OPT_KERNEL_CACHE, "kernel_cache"},
{OPT_MAX_READ, "max_read=%u"},
{OPT_ERR, NULL}
};
......@@ -268,6 +271,7 @@ static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
char *p;
memset(d, 0, sizeof(struct fuse_mount_data));
d->fd = -1;
d->max_read = ~0;
while ((p = strsep(&opt, ",")) != NULL) {
int token;
......@@ -308,6 +312,12 @@ static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
d->flags |= FUSE_KERNEL_CACHE;
break;
case OPT_MAX_READ:
if (match_int(&args[0], &value))
return 0;
d->max_read = value;
break;
default:
return 0;
}
......@@ -329,6 +339,8 @@ static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
seq_puts(m, ",allow_other");
if (fc->flags & FUSE_KERNEL_CACHE)
seq_puts(m, ",kernel_cache");
if (fc->max_read != ~0)
seq_printf(m, ",max_read=%u", fc->max_read);
return 0;
}
......@@ -453,6 +465,9 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
fc->flags = d.flags;
fc->user_id = d.user_id;
fc->max_read = d.max_read;
if (fc->max_read / PAGE_CACHE_SIZE < fc->bdi.ra_pages)
fc->bdi.ra_pages = fc->max_read / PAGE_CACHE_SIZE;
err = -ENOMEM;
root = get_root_inode(sb, d.rootmode);
......
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