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![Jeff Layton](/assets/img/avatar_default.png)
This is the second attempt to fix the problem whereby a COMMIT call causes a lease break and triggers a possible deadlock. The problem is that nfsd attempts to break a lease on a COMMIT call. This triggers a delegation recall if the lease is held for a delegation. If the client is the one holding the delegation and it's the same one on which it's issuing the COMMIT, then it can't return that delegation until the COMMIT is complete. But, nfsd won't complete the COMMIT until the delegation is returned. The client and server are essentially deadlocked until the state is marked bad (due to the client not responding on the callback channel). The first patch attempted to deal with this by eliminating the open of the file altogether and simply had nfsd_commit pass a NULL file pointer to the vfs_fsync_range. That would conflict with some work in progress by Christoph Hellwig to clean up the fsync interface, so this patch takes a different approach. This declares a new NFSD_MAY_NOT_BREAK_LEASE access flag that indicates to nfsd_open that it should not break any leases when opening the file, and has nfsd_commit set that flag on the nfsd_open call. For now, this patch leaves nfsd_commit opening the file with write access since I'm not clear on what sort of access would be more appropriate. Signed-off-by: Jeff Layton <jlayton@redhat.com> Cc: stable@kernel.org Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
102 lines
3.8 KiB
C
102 lines
3.8 KiB
C
/*
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* Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
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*/
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#ifndef LINUX_NFSD_VFS_H
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#define LINUX_NFSD_VFS_H
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#include "nfsfh.h"
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/*
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* Flags for nfsd_permission
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*/
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#define NFSD_MAY_NOP 0
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#define NFSD_MAY_EXEC 1 /* == MAY_EXEC */
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#define NFSD_MAY_WRITE 2 /* == MAY_WRITE */
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#define NFSD_MAY_READ 4 /* == MAY_READ */
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#define NFSD_MAY_SATTR 8
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#define NFSD_MAY_TRUNC 16
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#define NFSD_MAY_LOCK 32
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#define NFSD_MAY_OWNER_OVERRIDE 64
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#define NFSD_MAY_LOCAL_ACCESS 128 /* IRIX doing local access check on device special file*/
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#define NFSD_MAY_BYPASS_GSS_ON_ROOT 256
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#define NFSD_MAY_NOT_BREAK_LEASE 512
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#define NFSD_MAY_CREATE (NFSD_MAY_EXEC|NFSD_MAY_WRITE)
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#define NFSD_MAY_REMOVE (NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC)
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/*
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* Callback function for readdir
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*/
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typedef int (*nfsd_dirop_t)(struct inode *, struct dentry *, int, int);
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/* nfsd/vfs.c */
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int fh_lock_parent(struct svc_fh *, struct dentry *);
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int nfsd_racache_init(int);
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void nfsd_racache_shutdown(void);
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int nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
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struct svc_export **expp);
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__be32 nfsd_lookup(struct svc_rqst *, struct svc_fh *,
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const char *, unsigned int, struct svc_fh *);
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__be32 nfsd_lookup_dentry(struct svc_rqst *, struct svc_fh *,
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const char *, unsigned int,
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struct svc_export **, struct dentry **);
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__be32 nfsd_setattr(struct svc_rqst *, struct svc_fh *,
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struct iattr *, int, time_t);
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int nfsd_mountpoint(struct dentry *, struct svc_export *);
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#ifdef CONFIG_NFSD_V4
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__be32 nfsd4_set_nfs4_acl(struct svc_rqst *, struct svc_fh *,
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struct nfs4_acl *);
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int nfsd4_get_nfs4_acl(struct svc_rqst *, struct dentry *, struct nfs4_acl **);
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#endif /* CONFIG_NFSD_V4 */
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__be32 nfsd_create(struct svc_rqst *, struct svc_fh *,
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char *name, int len, struct iattr *attrs,
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int type, dev_t rdev, struct svc_fh *res);
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#ifdef CONFIG_NFSD_V3
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__be32 nfsd_access(struct svc_rqst *, struct svc_fh *, u32 *, u32 *);
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__be32 nfsd_create_v3(struct svc_rqst *, struct svc_fh *,
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char *name, int len, struct iattr *attrs,
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struct svc_fh *res, int createmode,
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u32 *verifier, int *truncp, int *created);
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__be32 nfsd_commit(struct svc_rqst *, struct svc_fh *,
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loff_t, unsigned long);
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#endif /* CONFIG_NFSD_V3 */
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__be32 nfsd_open(struct svc_rqst *, struct svc_fh *, int,
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int, struct file **);
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void nfsd_close(struct file *);
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__be32 nfsd_read(struct svc_rqst *, struct svc_fh *, struct file *,
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loff_t, struct kvec *, int, unsigned long *);
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__be32 nfsd_write(struct svc_rqst *, struct svc_fh *,struct file *,
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loff_t, struct kvec *,int, unsigned long *, int *);
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__be32 nfsd_readlink(struct svc_rqst *, struct svc_fh *,
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char *, int *);
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__be32 nfsd_symlink(struct svc_rqst *, struct svc_fh *,
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char *name, int len, char *path, int plen,
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struct svc_fh *res, struct iattr *);
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__be32 nfsd_link(struct svc_rqst *, struct svc_fh *,
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char *, int, struct svc_fh *);
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__be32 nfsd_rename(struct svc_rqst *,
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struct svc_fh *, char *, int,
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struct svc_fh *, char *, int);
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__be32 nfsd_remove(struct svc_rqst *,
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struct svc_fh *, char *, int);
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__be32 nfsd_unlink(struct svc_rqst *, struct svc_fh *, int type,
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char *name, int len);
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int nfsd_truncate(struct svc_rqst *, struct svc_fh *,
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unsigned long size);
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__be32 nfsd_readdir(struct svc_rqst *, struct svc_fh *,
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loff_t *, struct readdir_cd *, filldir_t);
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__be32 nfsd_statfs(struct svc_rqst *, struct svc_fh *,
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struct kstatfs *, int access);
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int nfsd_notify_change(struct inode *, struct iattr *);
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__be32 nfsd_permission(struct svc_rqst *, struct svc_export *,
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struct dentry *, int);
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int nfsd_sync_dir(struct dentry *dp);
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#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
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struct posix_acl *nfsd_get_posix_acl(struct svc_fh *, int);
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int nfsd_set_posix_acl(struct svc_fh *, int, struct posix_acl *);
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#endif
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#endif /* LINUX_NFSD_VFS_H */
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