[PATCH] fuse: clean up request accounting
FUSE allocated most requests from a fixed size pool filled at mount time.
However in some cases (release/forget) non-pool requests were used. File
locking operations aren't well served by the request pool, since they may
block indefinetly thus exhausting the pool.
This patch removes the request pool and always allocates requests on demand.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 6b8843d..4dc104c 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -72,10 +72,8 @@
*/
void fuse_reset_request(struct fuse_req *req)
{
- int preallocated = req->preallocated;
BUG_ON(atomic_read(&req->count) != 1);
fuse_request_init(req);
- req->preallocated = preallocated;
}
static void __fuse_get_request(struct fuse_req *req)
@@ -90,71 +88,28 @@
atomic_dec(&req->count);
}
-static struct fuse_req *do_get_request(struct fuse_conn *fc)
+struct fuse_req *fuse_get_req(struct fuse_conn *fc)
{
- struct fuse_req *req;
+ struct fuse_req *req = fuse_request_alloc();
+ if (!req)
+ return ERR_PTR(-ENOMEM);
- spin_lock(&fc->lock);
- BUG_ON(list_empty(&fc->unused_list));
- req = list_entry(fc->unused_list.next, struct fuse_req, list);
- list_del_init(&req->list);
- spin_unlock(&fc->lock);
+ atomic_inc(&fc->num_waiting);
fuse_request_init(req);
- req->preallocated = 1;
req->in.h.uid = current->fsuid;
req->in.h.gid = current->fsgid;
req->in.h.pid = current->pid;
return req;
}
-/* This can return NULL, but only in case it's interrupted by a SIGKILL */
-struct fuse_req *fuse_get_request(struct fuse_conn *fc)
-{
- int intr;
- sigset_t oldset;
-
- atomic_inc(&fc->num_waiting);
- block_sigs(&oldset);
- intr = down_interruptible(&fc->outstanding_sem);
- restore_sigs(&oldset);
- if (intr) {
- atomic_dec(&fc->num_waiting);
- return NULL;
- }
- return do_get_request(fc);
-}
-
-/* Must be called with fc->lock held */
-static void fuse_putback_request(struct fuse_conn *fc, struct fuse_req *req)
-{
- if (req->preallocated) {
- atomic_dec(&fc->num_waiting);
- list_add(&req->list, &fc->unused_list);
- } else
- fuse_request_free(req);
-
- /* If we are in debt decrease that first */
- if (fc->outstanding_debt)
- fc->outstanding_debt--;
- else
- up(&fc->outstanding_sem);
-}
-
void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
{
if (atomic_dec_and_test(&req->count)) {
- spin_lock(&fc->lock);
- fuse_putback_request(fc, req);
- spin_unlock(&fc->lock);
+ atomic_dec(&fc->num_waiting);
+ fuse_request_free(req);
}
}
-static void fuse_put_request_locked(struct fuse_conn *fc, struct fuse_req *req)
-{
- if (atomic_dec_and_test(&req->count))
- fuse_putback_request(fc, req);
-}
-
void fuse_release_background(struct fuse_conn *fc, struct fuse_req *req)
{
iput(req->inode);
@@ -189,9 +144,9 @@
list_del(&req->list);
req->state = FUSE_REQ_FINISHED;
if (!req->background) {
- wake_up(&req->waitq);
- fuse_put_request_locked(fc, req);
spin_unlock(&fc->lock);
+ wake_up(&req->waitq);
+ fuse_put_request(fc, req);
} else {
void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
req->end = NULL;
@@ -302,16 +257,6 @@
req->in.h.unique = fc->reqctr;
req->in.h.len = sizeof(struct fuse_in_header) +
len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
- if (!req->preallocated) {
- /* If request is not preallocated (either FORGET or
- RELEASE), then still decrease outstanding_sem, so
- user can't open infinite number of files while not
- processing the RELEASE requests. However for
- efficiency do it without blocking, so if down()
- would block, just increase the debt instead */
- if (down_trylock(&fc->outstanding_sem))
- fc->outstanding_debt++;
- }
list_add_tail(&req->list, &fc->pending);
req->state = FUSE_REQ_PENDING;
wake_up(&fc->waitq);
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 256355b..8d7546e 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -117,8 +117,8 @@
return 0;
fc = get_fuse_conn(inode);
- req = fuse_get_request(fc);
- if (!req)
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
return 0;
fuse_lookup_init(req, entry->d_parent->d_inode, entry, &outarg);
@@ -188,9 +188,9 @@
if (entry->d_name.len > FUSE_NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
- req = fuse_get_request(fc);
- if (!req)
- return ERR_PTR(-EINTR);
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return ERR_PTR(PTR_ERR(req));
fuse_lookup_init(req, dir, entry, &outarg);
request_send(fc, req);
@@ -244,15 +244,14 @@
struct file *file;
int flags = nd->intent.open.flags - 1;
- err = -ENOSYS;
if (fc->no_create)
- goto out;
+ return -ENOSYS;
- err = -EINTR;
- req = fuse_get_request(fc);
- if (!req)
- goto out;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+ err = -ENOMEM;
ff = fuse_file_alloc();
if (!ff)
goto out_put_request;
@@ -314,7 +313,6 @@
fuse_file_free(ff);
out_put_request:
fuse_put_request(fc, req);
- out:
return err;
}
@@ -375,9 +373,9 @@
{
struct fuse_mknod_in inarg;
struct fuse_conn *fc = get_fuse_conn(dir);
- struct fuse_req *req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ struct fuse_req *req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg));
inarg.mode = mode;
@@ -407,9 +405,9 @@
{
struct fuse_mkdir_in inarg;
struct fuse_conn *fc = get_fuse_conn(dir);
- struct fuse_req *req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ struct fuse_req *req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg));
inarg.mode = mode;
@@ -427,9 +425,9 @@
{
struct fuse_conn *fc = get_fuse_conn(dir);
unsigned len = strlen(link) + 1;
- struct fuse_req *req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ struct fuse_req *req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
req->in.h.opcode = FUSE_SYMLINK;
req->in.numargs = 2;
@@ -444,9 +442,9 @@
{
int err;
struct fuse_conn *fc = get_fuse_conn(dir);
- struct fuse_req *req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ struct fuse_req *req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
req->in.h.opcode = FUSE_UNLINK;
req->in.h.nodeid = get_node_id(dir);
@@ -476,9 +474,9 @@
{
int err;
struct fuse_conn *fc = get_fuse_conn(dir);
- struct fuse_req *req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ struct fuse_req *req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
req->in.h.opcode = FUSE_RMDIR;
req->in.h.nodeid = get_node_id(dir);
@@ -504,9 +502,9 @@
int err;
struct fuse_rename_in inarg;
struct fuse_conn *fc = get_fuse_conn(olddir);
- struct fuse_req *req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ struct fuse_req *req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg));
inarg.newdir = get_node_id(newdir);
@@ -553,9 +551,9 @@
struct fuse_link_in inarg;
struct inode *inode = entry->d_inode;
struct fuse_conn *fc = get_fuse_conn(inode);
- struct fuse_req *req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ struct fuse_req *req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg));
inarg.oldnodeid = get_node_id(inode);
@@ -583,9 +581,9 @@
int err;
struct fuse_attr_out arg;
struct fuse_conn *fc = get_fuse_conn(inode);
- struct fuse_req *req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ struct fuse_req *req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
req->in.h.opcode = FUSE_GETATTR;
req->in.h.nodeid = get_node_id(inode);
@@ -673,9 +671,9 @@
if (fc->no_access)
return 0;
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg));
inarg.mask = mask;
@@ -780,9 +778,9 @@
if (is_bad_inode(inode))
return -EIO;
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
page = alloc_page(GFP_KERNEL);
if (!page) {
@@ -809,11 +807,11 @@
{
struct inode *inode = dentry->d_inode;
struct fuse_conn *fc = get_fuse_conn(inode);
- struct fuse_req *req = fuse_get_request(fc);
+ struct fuse_req *req = fuse_get_req(fc);
char *link;
- if (!req)
- return ERR_PTR(-EINTR);
+ if (IS_ERR(req))
+ return ERR_PTR(PTR_ERR(req));
link = (char *) __get_free_page(GFP_KERNEL);
if (!link) {
@@ -933,9 +931,9 @@
}
}
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg));
iattr_to_fattr(attr, &inarg);
@@ -995,9 +993,9 @@
if (fc->no_setxattr)
return -EOPNOTSUPP;
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg));
inarg.size = size;
@@ -1035,9 +1033,9 @@
if (fc->no_getxattr)
return -EOPNOTSUPP;
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg));
inarg.size = size;
@@ -1085,9 +1083,9 @@
if (fc->no_listxattr)
return -EOPNOTSUPP;
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg));
inarg.size = size;
@@ -1131,9 +1129,9 @@
if (fc->no_removexattr)
return -EOPNOTSUPP;
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
req->in.h.opcode = FUSE_REMOVEXATTR;
req->in.h.nodeid = get_node_id(inode);
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 3ac39c0..e4f041a 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -22,9 +22,9 @@
struct fuse_req *req;
int err;
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg));
inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
@@ -184,9 +184,9 @@
if (fc->no_flush)
return 0;
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg));
inarg.fh = ff->fh;
@@ -223,9 +223,9 @@
if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
return 0;
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg));
inarg.fh = ff->fh;
@@ -297,9 +297,9 @@
if (is_bad_inode(inode))
goto out;
- err = -EINTR;
- req = fuse_get_request(fc);
- if (!req)
+ req = fuse_get_req(fc);
+ err = PTR_ERR(req);
+ if (IS_ERR(req))
goto out;
req->out.page_zeroing = 1;
@@ -368,10 +368,10 @@
(req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
req->pages[req->num_pages - 1]->index + 1 != page->index)) {
fuse_send_readpages(req, data->file, inode);
- data->req = req = fuse_get_request(fc);
- if (!req) {
+ data->req = req = fuse_get_req(fc);
+ if (IS_ERR(req)) {
unlock_page(page);
- return -EINTR;
+ return PTR_ERR(req);
}
}
req->pages[req->num_pages] = page;
@@ -392,9 +392,9 @@
data.file = file;
data.inode = inode;
- data.req = fuse_get_request(fc);
- if (!data.req)
- return -EINTR;
+ data.req = fuse_get_req(fc);
+ if (IS_ERR(data.req))
+ return PTR_ERR(data.req);
err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
if (!err) {
@@ -455,9 +455,9 @@
if (is_bad_inode(inode))
return -EIO;
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
req->num_pages = 1;
req->pages[0] = page;
@@ -532,9 +532,9 @@
if (is_bad_inode(inode))
return -EIO;
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
while (count) {
size_t nres;
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 6ed812f..242e69c 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -18,9 +18,6 @@
/** Max number of pages that can be used in a single read request */
#define FUSE_MAX_PAGES_PER_REQ 32
-/** If more requests are outstanding, then the operation will block */
-#define FUSE_MAX_OUTSTANDING 10
-
/** It could be as large as PATH_MAX, but would that have any uses? */
#define FUSE_NAME_MAX 1024
@@ -131,8 +128,8 @@
* A request to the client
*/
struct fuse_req {
- /** This can be on either unused_list, pending processing or
- io lists in fuse_conn */
+ /** This can be on either pending processing or io lists in
+ fuse_conn */
struct list_head list;
/** Entry on the background list */
@@ -150,9 +147,6 @@
/** True if the request has reply */
unsigned isreply:1;
- /** The request is preallocated */
- unsigned preallocated:1;
-
/** The request was interrupted */
unsigned interrupted:1;
@@ -247,19 +241,9 @@
interrupted request) */
struct list_head background;
- /** Controls the maximum number of outstanding requests */
- struct semaphore outstanding_sem;
-
- /** This counts the number of outstanding requests if
- outstanding_sem would go negative */
- unsigned outstanding_debt;
-
/** RW semaphore for exclusion with fuse_put_super() */
struct rw_semaphore sbput_sem;
- /** The list of unused requests */
- struct list_head unused_list;
-
/** The next unique request id */
u64 reqctr;
@@ -452,11 +436,11 @@
/**
* Reserve a preallocated request
*/
-struct fuse_req *fuse_get_request(struct fuse_conn *fc);
+struct fuse_req *fuse_get_req(struct fuse_conn *fc);
/**
- * Decrement reference count of a request. If count goes to zero put
- * on unused list (preallocated) or free request (not preallocated).
+ * Decrement reference count of a request. If count goes to zero free
+ * the request.
*/
void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index cc58deb..824ebbc 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -243,9 +243,9 @@
struct fuse_statfs_out outarg;
int err;
- req = fuse_get_request(fc);
- if (!req)
- return -EINTR;
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
memset(&outarg, 0, sizeof(outarg));
req->in.numargs = 0;
@@ -370,15 +370,7 @@
static void fuse_conn_release(struct kobject *kobj)
{
- struct fuse_conn *fc = get_fuse_conn_kobj(kobj);
-
- while (!list_empty(&fc->unused_list)) {
- struct fuse_req *req;
- req = list_entry(fc->unused_list.next, struct fuse_req, list);
- list_del(&req->list);
- fuse_request_free(req);
- }
- kfree(fc);
+ kfree(get_fuse_conn_kobj(kobj));
}
static struct fuse_conn *new_conn(void)
@@ -387,27 +379,16 @@
fc = kzalloc(sizeof(*fc), GFP_KERNEL);
if (fc) {
- int i;
spin_lock_init(&fc->lock);
init_waitqueue_head(&fc->waitq);
INIT_LIST_HEAD(&fc->pending);
INIT_LIST_HEAD(&fc->processing);
INIT_LIST_HEAD(&fc->io);
- INIT_LIST_HEAD(&fc->unused_list);
INIT_LIST_HEAD(&fc->background);
- sema_init(&fc->outstanding_sem, 1); /* One for INIT */
init_rwsem(&fc->sbput_sem);
kobj_set_kset_s(fc, connections_subsys);
kobject_init(&fc->kobj);
atomic_set(&fc->num_waiting, 0);
- for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) {
- struct fuse_req *req = fuse_request_alloc();
- if (!req) {
- kobject_put(&fc->kobj);
- return NULL;
- }
- list_add(&req->list, &fc->unused_list);
- }
fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
fc->bdi.unplug_io_fn = default_unplug_io_fn;
fc->reqctr = 0;
@@ -438,7 +419,6 @@
static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
{
- int i;
struct fuse_init_out *arg = &req->misc.init_out;
if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
@@ -457,22 +437,11 @@
fc->minor = arg->minor;
fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
}
-
- /* After INIT reply is received other requests can go
- out. So do (FUSE_MAX_OUTSTANDING - 1) number of
- up()s on outstanding_sem. The last up() is done in
- fuse_putback_request() */
- for (i = 1; i < FUSE_MAX_OUTSTANDING; i++)
- up(&fc->outstanding_sem);
-
fuse_put_request(fc, req);
}
-static void fuse_send_init(struct fuse_conn *fc)
+static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
{
- /* This is called from fuse_read_super() so there's guaranteed
- to be exactly one request available */
- struct fuse_req *req = fuse_get_request(fc);
struct fuse_init_in *arg = &req->misc.init_in;
arg->major = FUSE_KERNEL_VERSION;
@@ -508,6 +477,7 @@
struct fuse_mount_data d;
struct file *file;
struct dentry *root_dentry;
+ struct fuse_req *init_req;
int err;
if (!parse_fuse_opt((char *) data, &d))
@@ -554,13 +524,17 @@
goto err;
}
+ init_req = fuse_request_alloc();
+ if (!init_req)
+ goto err_put_root;
+
err = kobject_set_name(&fc->kobj, "%llu", conn_id());
if (err)
- goto err_put_root;
+ goto err_free_req;
err = kobject_add(&fc->kobj);
if (err)
- goto err_put_root;
+ goto err_free_req;
sb->s_root = root_dentry;
fc->mounted = 1;
@@ -574,10 +548,12 @@
*/
fput(file);
- fuse_send_init(fc);
+ fuse_send_init(fc, init_req);
return 0;
+ err_free_req:
+ fuse_request_free(init_req);
err_put_root:
dput(root_dentry);
err: