mirrors/libfuse
0
0
Fork 0
mirror of https://github.com/libfuse/libfuse.git synced 2024-11-26 21:54:30 +08:00
Code Issues Packages Projects Releases Wiki Activity

fix

Browse Source
This commit is contained in:
Miklos Szeredi 2006-04-21 14:09:28 +00:00
parent 7a2814c8b4
commit 5fe07d6198
4 changed files with 55 additions and 40 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
ChangeLog
View File

@ -1,4 +1,12 @@
2006-04-11 Csaba Henk <csaba.henk@creo.hu>
2006-04-21 Miklos Szeredi <miklos@szeredi.hu>
* kernel: fix fput deadlock fix, the lockless solution could lead
to "VFS: busy inodes after umount..."
* kernel: fix race between checking and setting file->private_data
for the device. Found by Al Viro
2006-04-11 Miklos Szeredi <miklos@szeredi.hu>
* kernel: remove request pool, instead allocate requests on
demand. Account the number of background requests, and if they go

35
kernel/dev.c
View File

@ -168,14 +168,24 @@ void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
}
}
void fuse_remove_background(struct fuse_conn *fc, struct fuse_req *req)
/*
* Called with sbput_sem held for read (request_end) or write
* (fuse_put_super). By the time fuse_put_super() is finished, all
* inodes belonging to background requests must be released, so the
* iputs have to be done within the locked region.
*/
void fuse_release_background(struct fuse_conn *fc, struct fuse_req *req)
{
list_del_init(&req->bg_entry);
iput(req->inode);
iput(req->inode2);
spin_lock(&fc->lock);
list_del(&req->bg_entry);
if (fc->num_background == FUSE_MAX_BACKGROUND) {
fc->blocked = 0;
wake_up_all(&fc->blocked_waitq);
}
fc->num_background--;
spin_unlock(&fc->lock);
}
/*
@ -205,27 +215,22 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
wake_up(&req->waitq);
fuse_put_request(fc, req);
} else {
struct inode *inode = req->inode;
struct inode *inode2 = req->inode2;
struct file *file = req->file;
void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
req->end = NULL;
req->inode = NULL;
req->inode2 = NULL;
req->file = NULL;
if (!list_empty(&req->bg_entry))
fuse_remove_background(fc, req);
spin_unlock(&fc->lock);
down_read(&fc->sbput_sem);
if (fc->mounted)
fuse_release_background(fc, req);
up_read(&fc->sbput_sem);
/* fput must go outside sbput_sem, otherwise it can deadlock */
if (req->file)
fput(req->file);
if (end)
end(fc, req);
else
fuse_put_request(fc, req);
if (file)
fput(file);
iput(inode);
iput(inode2);
}
}

10
kernel/fuse_i.h
View File

@ -355,9 +355,15 @@ struct fuse_conn {
/** waitq for blocked connection */
wait_queue_head_t blocked_waitq;
/** RW semaphore for exclusion with fuse_put_super() */
struct rw_semaphore sbput_sem;
/** The next unique request id */
u64 reqctr;
/** Mount is active */
unsigned mounted;
/** Connection established, cleared on umount, connection
abort and device release */
unsigned connected;
@ -570,9 +576,9 @@ void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req);
void request_send_background(struct fuse_conn *fc, struct fuse_req *req);
/**
* Remove request from the the background list
* Release inodes and file associated with background request
*/
void fuse_remove_background(struct fuse_conn *fc, struct fuse_req *req);
void fuse_release_background(struct fuse_conn *fc, struct fuse_req *req);
/** Abort all requests */
void fuse_abort_conn(struct fuse_conn *fc);

40
kernel/inode.c
View File

@ -278,26 +278,17 @@ static void fuse_put_super(struct super_block *sb)
{
struct fuse_conn *fc = get_fuse_conn_super(sb);
down_write(&fc->sbput_sem);
while (!list_empty(&fc->background))
fuse_release_background(fc,
list_entry(fc->background.next,
struct fuse_req, bg_entry));
spin_lock(&fc->lock);
fc->mounted = 0;
fc->connected = 0;
while (!list_empty(&fc->background)) {
struct fuse_req *req = list_entry(fc->background.next,
struct fuse_req, bg_entry);
struct inode *inode = req->inode;
struct inode *inode2 = req->inode2;
/* File would hold a reference to vfsmount */
BUG_ON(req->file);
req->inode = NULL;
req->inode2 = NULL;
fuse_remove_background(fc, req);
spin_unlock(&fc->lock);
iput(inode);
iput(inode2);
spin_lock(&fc->lock);
}
spin_unlock(&fc->lock);
up_write(&fc->sbput_sem);
/* Flush all readers on this fs */
kill_fasync(&fc->fasync, SIGIO, POLL_IN);
wake_up_all(&fc->waitq);
@ -497,6 +488,7 @@ static struct fuse_conn *new_conn(void)
INIT_LIST_HEAD(&fc->processing);
INIT_LIST_HEAD(&fc->io);
INIT_LIST_HEAD(&fc->background);
init_rwsem(&fc->sbput_sem);
#ifdef KERNEL_2_6
kobj_set_kset_s(fc, connections_subsys);
kobject_init(&fc->kobj);
@ -692,11 +684,6 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
if (file->f_op != &fuse_dev_operations)
return -EINVAL;
/* Setting file->private_data can't race with other mount()
instances, since BKL is held for ->get_sb() */
if (file->private_data)
return -EINVAL;
fc = new_conn();
if (!fc)
return -ENOMEM;
@ -734,7 +721,14 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
goto err_free_req;
#endif
/* Setting file->private_data can't race with other mount()
instances, since BKL is held for ->get_sb() */
err = -EINVAL;
if (file->private_data)
goto err_kobject_del;
sb->s_root = root_dentry;
fc->mounted = 1;
fc->connected = 1;
kobject_get(&fc->kobj);
file->private_data = fc;
@ -749,7 +743,9 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
return 0;
err_kobject_del:
#ifdef KERNEL_2_6
kobject_del(&fc->kobj);
err_free_req:
fuse_request_free(init_req);
#endif