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591ad7feae
Currently, wait queue, used for polling of RPC pipe changes from user-space, is a part of RPC pipe. But the pipe data itself can be released on NFS umount prior to dentry-inode pair, connected to it (is case of this pair is open by some process). This is not a problem for almost all pipe users, because all PipeFS file operations checks pipe reference prior to using it. Except evenfd. This thing registers itself with "poll" file operation and thus has a reference to pipe wait queue. This leads to oopses on destroying eventfd after NFS umount (like rpc_idmapd do) since not pipe data left to the point already. The solution is to wait queue from pipe data to internal RPC inode data. This looks more logical, because this wiat queue used only for user-space processes, which already holds inode reference. Note: upcalls have to get pipe->dentry prior to dereferecing wait queue to make sure, that mount point won't disappear from underneath us. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
98 lines
2.5 KiB
C
98 lines
2.5 KiB
C
#ifndef _LINUX_SUNRPC_RPC_PIPE_FS_H
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#define _LINUX_SUNRPC_RPC_PIPE_FS_H
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#ifdef __KERNEL__
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#include <linux/workqueue.h>
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struct rpc_pipe_msg {
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struct list_head list;
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void *data;
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size_t len;
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size_t copied;
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int errno;
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};
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struct rpc_pipe_ops {
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ssize_t (*upcall)(struct file *, struct rpc_pipe_msg *, char __user *, size_t);
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ssize_t (*downcall)(struct file *, const char __user *, size_t);
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void (*release_pipe)(struct inode *);
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int (*open_pipe)(struct inode *);
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void (*destroy_msg)(struct rpc_pipe_msg *);
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};
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struct rpc_pipe {
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struct list_head pipe;
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struct list_head in_upcall;
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struct list_head in_downcall;
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int pipelen;
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int nreaders;
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int nwriters;
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#define RPC_PIPE_WAIT_FOR_OPEN 1
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int flags;
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struct delayed_work queue_timeout;
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const struct rpc_pipe_ops *ops;
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spinlock_t lock;
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struct dentry *dentry;
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};
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struct rpc_inode {
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struct inode vfs_inode;
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void *private;
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struct rpc_pipe *pipe;
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wait_queue_head_t waitq;
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};
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static inline struct rpc_inode *
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RPC_I(struct inode *inode)
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{
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return container_of(inode, struct rpc_inode, vfs_inode);
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}
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enum {
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SUNRPC_PIPEFS_NFS_PRIO,
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SUNRPC_PIPEFS_RPC_PRIO,
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};
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extern int rpc_pipefs_notifier_register(struct notifier_block *);
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extern void rpc_pipefs_notifier_unregister(struct notifier_block *);
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enum {
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RPC_PIPEFS_MOUNT,
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RPC_PIPEFS_UMOUNT,
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};
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extern struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
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const unsigned char *dir_name);
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extern void rpc_pipefs_init_net(struct net *net);
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extern struct super_block *rpc_get_sb_net(const struct net *net);
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extern void rpc_put_sb_net(const struct net *net);
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extern ssize_t rpc_pipe_generic_upcall(struct file *, struct rpc_pipe_msg *,
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char __user *, size_t);
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extern int rpc_queue_upcall(struct rpc_pipe *, struct rpc_pipe_msg *);
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struct rpc_clnt;
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extern struct dentry *rpc_create_client_dir(struct dentry *, struct qstr *, struct rpc_clnt *);
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extern int rpc_remove_client_dir(struct dentry *);
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struct cache_detail;
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extern struct dentry *rpc_create_cache_dir(struct dentry *,
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struct qstr *,
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umode_t umode,
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struct cache_detail *);
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extern void rpc_remove_cache_dir(struct dentry *);
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extern int rpc_rmdir(struct dentry *dentry);
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struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags);
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void rpc_destroy_pipe_data(struct rpc_pipe *pipe);
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extern struct dentry *rpc_mkpipe_dentry(struct dentry *, const char *, void *,
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struct rpc_pipe *);
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extern int rpc_unlink(struct dentry *);
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extern int register_rpc_pipefs(void);
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extern void unregister_rpc_pipefs(void);
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#endif
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#endif
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