forked from Minki/linux
d3fec424b2
This is an variation on the patch sent by Christoph Hellwig which kills file_count abuse by the Coda kernel module by moving the coda_flush functionality into coda_release. However part of reason we were using the coda_flush callback was to allow Coda to pass errors that occur during writeback from the userspace cache manager back to close(). As Al Viro explained on linux-fsdevel, it is impossible to guarantee that such errors can in fact be returned back to the caller. There are many cases where the last reference to a file is not released by the close system call and it is also impossible to pick some close as a 'last-close' and delay it until all other references have been destroyed. The CODA_STORE/CODA_RELEASE upcall combination is clearly a broken design, and it is better to remove it completely. Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@ftp.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
99 lines
3.0 KiB
C
99 lines
3.0 KiB
C
/*
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* Coda File System, Linux Kernel module
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*
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* Original version, adapted from cfs_mach.c, (C) Carnegie Mellon University
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* Linux modifications (C) 1996, Peter J. Braam
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* Rewritten for Linux 2.1 (C) 1997 Carnegie Mellon University
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*
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* Carnegie Mellon University encourages users of this software to
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* contribute improvements to the Coda project.
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*/
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#ifndef _LINUX_CODA_FS
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#define _LINUX_CODA_FS
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#include <linux/kernel.h>
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#include <linux/param.h>
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <linux/slab.h>
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#include <linux/wait.h>
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#include <linux/types.h>
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#include <linux/fs.h>
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#include <linux/coda_fs_i.h>
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/* operations */
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extern const struct inode_operations coda_dir_inode_operations;
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extern const struct inode_operations coda_file_inode_operations;
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extern const struct inode_operations coda_ioctl_inode_operations;
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extern const struct address_space_operations coda_file_aops;
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extern const struct address_space_operations coda_symlink_aops;
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extern const struct file_operations coda_dir_operations;
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extern const struct file_operations coda_file_operations;
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extern const struct file_operations coda_ioctl_operations;
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/* operations shared over more than one file */
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int coda_open(struct inode *i, struct file *f);
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int coda_release(struct inode *i, struct file *f);
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int coda_permission(struct inode *inode, int mask, struct nameidata *nd);
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int coda_revalidate_inode(struct dentry *);
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int coda_getattr(struct vfsmount *, struct dentry *, struct kstat *);
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int coda_setattr(struct dentry *, struct iattr *);
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/* this file: heloers */
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static __inline__ struct CodaFid *coda_i2f(struct inode *);
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static __inline__ char *coda_i2s(struct inode *);
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static __inline__ void coda_flag_inode(struct inode *, int flag);
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char *coda_f2s(struct CodaFid *f);
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int coda_isroot(struct inode *i);
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int coda_iscontrol(const char *name, size_t length);
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void coda_vattr_to_iattr(struct inode *, struct coda_vattr *);
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void coda_iattr_to_vattr(struct iattr *, struct coda_vattr *);
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unsigned short coda_flags_to_cflags(unsigned short);
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/* sysctl.h */
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void coda_sysctl_init(void);
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void coda_sysctl_clean(void);
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#define CODA_ALLOC(ptr, cast, size) do { \
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if (size < PAGE_SIZE) \
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ptr = kmalloc((unsigned long) size, GFP_KERNEL); \
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else \
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ptr = (cast)vmalloc((unsigned long) size); \
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if (!ptr) \
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printk("kernel malloc returns 0 at %s:%d\n", __FILE__, __LINE__); \
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else memset( ptr, 0, size ); \
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} while (0)
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#define CODA_FREE(ptr,size) \
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do { if (size < PAGE_SIZE) kfree((ptr)); else vfree((ptr)); } while (0)
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/* inode to cnode access functions */
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static inline struct coda_inode_info *ITOC(struct inode *inode)
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{
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return list_entry(inode, struct coda_inode_info, vfs_inode);
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}
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static __inline__ struct CodaFid *coda_i2f(struct inode *inode)
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{
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return &(ITOC(inode)->c_fid);
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}
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static __inline__ char *coda_i2s(struct inode *inode)
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{
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return coda_f2s(&(ITOC(inode)->c_fid));
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}
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/* this will not zap the inode away */
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static __inline__ void coda_flag_inode(struct inode *inode, int flag)
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{
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ITOC(inode)->c_flags |= flag;
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}
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#endif
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