[net-next-2.6.git] / fs / coda / dir.c


/*
 * Directory operations for Coda filesystem
 * Original version: (C) 1996 P. Braam and M. Callahan
 * Rewritten for Linux 2.1. (C) 1997 Carnegie Mellon University
 * 
 * Carnegie Mellon encourages users to contribute improvements to
 * the Coda project. Contact Peter Braam (coda@cs.cmu.edu).
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/smp_lock.h>

#include <asm/uaccess.h>

#include <linux/coda.h>
#include <linux/coda_linux.h>
#include <linux/coda_psdev.h>
#include <linux/coda_fs_i.h>
#include <linux/coda_cache.h>

#include "coda_int.h"

/* dir inode-ops */
static int coda_create(struct inode *dir, struct dentry *new, int mode, struct nameidata *nd);
static struct dentry *coda_lookup(struct inode *dir, struct dentry *target, struct nameidata *nd);
static int coda_link(struct dentry *old_dentry, struct inode *dir_inode, 
		     struct dentry *entry);
static int coda_unlink(struct inode *dir_inode, struct dentry *entry);
static int coda_symlink(struct inode *dir_inode, struct dentry *entry,
			const char *symname);
static int coda_mkdir(struct inode *dir_inode, struct dentry *entry, int mode);
static int coda_rmdir(struct inode *dir_inode, struct dentry *entry);
static int coda_rename(struct inode *old_inode, struct dentry *old_dentry, 
                       struct inode *new_inode, struct dentry *new_dentry);

/* dir file-ops */
static int coda_readdir(struct file *file, void *buf, filldir_t filldir);

/* dentry ops */
static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd);
static int coda_dentry_delete(struct dentry *);

/* support routines */
static int coda_venus_readdir(struct file *coda_file, void *buf,
			      filldir_t filldir);

/* same as fs/bad_inode.c */
static int coda_return_EIO(void)
{
	return -EIO;
}
#define CODA_EIO_ERROR ((void *) (coda_return_EIO))

static const struct dentry_operations coda_dentry_operations =
{
	.d_revalidate	= coda_dentry_revalidate,
	.d_delete	= coda_dentry_delete,
};

const struct inode_operations coda_dir_inode_operations =
{
	.create		= coda_create,
	.lookup		= coda_lookup,
	.link		= coda_link,
	.unlink		= coda_unlink,
	.symlink	= coda_symlink,
	.mkdir		= coda_mkdir,
	.rmdir		= coda_rmdir,
	.mknod		= CODA_EIO_ERROR,
	.rename		= coda_rename,
	.permission	= coda_permission,
	.getattr	= coda_getattr,
	.setattr	= coda_setattr,
};

const struct file_operations coda_dir_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.readdir	= coda_readdir,
	.open		= coda_open,
	.release	= coda_release,
	.fsync		= coda_fsync,
};


/* inode operations for directories */
/* access routines: lookup, readlink, permission */
static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, struct nameidata *nd)
{
	struct inode *inode = NULL;
	struct CodaFid resfid = { { 0, } };
	int type = 0;
	int error = 0;
	const char *name = entry->d_name.name;
	size_t length = entry->d_name.len;

	if (length > CODA_MAXNAMLEN) {
		printk(KERN_ERR "name too long: lookup, %s (%*s)\n",
		       coda_i2s(dir), (int)length, name);
		return ERR_PTR(-ENAMETOOLONG);
	}

	/* control object, create inode on the fly */
	if (coda_isroot(dir) && coda_iscontrol(name, length)) {
		error = coda_cnode_makectl(&inode, dir->i_sb);
		type = CODA_NOCACHE;
		goto exit;
	}

	lock_kernel();

	error = venus_lookup(dir->i_sb, coda_i2f(dir), name, length,
			     &type, &resfid);
	if (!error)
		error = coda_cnode_make(&inode, &resfid, dir->i_sb);

	unlock_kernel();

	if (error && error != -ENOENT)
		return ERR_PTR(error);

exit:
	entry->d_op = &coda_dentry_operations;

	if (inode && (type & CODA_NOCACHE))
		coda_flag_inode(inode, C_VATTR | C_PURGE);

	return d_splice_alias(inode, entry);
}


int coda_permission(struct inode *inode, int mask)
{
        int error = 0;

	mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
 
	if (!mask)
		return 0; 

	if ((mask & MAY_EXEC) && !execute_ok(inode))
		return -EACCES;

	lock_kernel();

	if (coda_cache_check(inode, mask))
		goto out; 

        error = venus_access(inode->i_sb, coda_i2f(inode), mask);
    
	if (!error)
		coda_cache_enter(inode, mask);

 out:
	unlock_kernel();
	return error;
}


static inline void coda_dir_update_mtime(struct inode *dir)
{
#ifdef REQUERY_VENUS_FOR_MTIME
	/* invalidate the directory cnode's attributes so we refetch the
	 * attributes from venus next time the inode is referenced */
	coda_flag_inode(dir, C_VATTR);
#else
	/* optimistically we can also act as if our nose bleeds. The
	 * granularity of the mtime is coarse anyways so we might actually be
	 * right most of the time. Note: we only do this for directories. */
	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
#endif
}

/* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
 * trick to fool GNU find's optimizations. If we can't be sure of the link
 * (because of volume mount points) we set i_nlink to 1 which forces find
 * to consider every child as a possible directory. We should also never
 * see an increment or decrement for deleted directories where i_nlink == 0 */
static inline void coda_dir_inc_nlink(struct inode *dir)
{
	if (dir->i_nlink >= 2)
		inc_nlink(dir);
}

static inline void coda_dir_drop_nlink(struct inode *dir)
{
	if (dir->i_nlink > 2)
		drop_nlink(dir);
}

/* creation routines: create, mknod, mkdir, link, symlink */
static int coda_create(struct inode *dir, struct dentry *de, int mode, struct nameidata *nd)
{
        int error=0;
	const char *name=de->d_name.name;
	int length=de->d_name.len;
	struct inode *inode;
	struct CodaFid newfid;
	struct coda_vattr attrs;

	lock_kernel();

	if (coda_isroot(dir) && coda_iscontrol(name, length)) {
		unlock_kernel();
		return -EPERM;
	}

	error = venus_create(dir->i_sb, coda_i2f(dir), name, length, 
				0, mode, &newfid, &attrs);

        if ( error ) {
		unlock_kernel();
		d_drop(de);
		return error;
	}

	inode = coda_iget(dir->i_sb, &newfid, &attrs);
	if ( IS_ERR(inode) ) {
		unlock_kernel();
		d_drop(de);
		return PTR_ERR(inode);
	}

	/* invalidate the directory cnode's attributes */
	coda_dir_update_mtime(dir);
	unlock_kernel();
	d_instantiate(de, inode);
	return 0;
}

static int coda_mkdir(struct inode *dir, struct dentry *de, int mode)
{
	struct inode *inode;
	struct coda_vattr attrs;
	const char *name = de->d_name.name;
	int len = de->d_name.len;
	int error;
	struct CodaFid newfid;

	lock_kernel();

	if (coda_isroot(dir) && coda_iscontrol(name, len)) {
		unlock_kernel();
		return -EPERM;
	}

	attrs.va_mode = mode;
	error = venus_mkdir(dir->i_sb, coda_i2f(dir), 
			       name, len, &newfid, &attrs);
        
        if ( error ) {
		unlock_kernel();
		d_drop(de);
		return error;
        }
         
	inode = coda_iget(dir->i_sb, &newfid, &attrs);
	if ( IS_ERR(inode) ) {
		unlock_kernel();
		d_drop(de);
		return PTR_ERR(inode);
	}

	/* invalidate the directory cnode's attributes */
	coda_dir_inc_nlink(dir);
	coda_dir_update_mtime(dir);
	unlock_kernel();
	d_instantiate(de, inode);
	return 0;
}

/* try to make de an entry in dir_inodde linked to source_de */ 
static int coda_link(struct dentry *source_de, struct inode *dir_inode, 
	  struct dentry *de)
{
	struct inode *inode = source_de->d_inode;
        const char * name = de->d_name.name;
	int len = de->d_name.len;
	int error;

	lock_kernel();

	if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) {
		unlock_kernel();
		return -EPERM;
	}

	error = venus_link(dir_inode->i_sb, coda_i2f(inode),
			   coda_i2f(dir_inode), (const char *)name, len);

	if (error) {
		d_drop(de);
		goto out;
	}

	coda_dir_update_mtime(dir_inode);
	atomic_inc(&inode->i_count);
	d_instantiate(de, inode);
	inc_nlink(inode);

out:
	unlock_kernel();
	return(error);
}


static int coda_symlink(struct inode *dir_inode, struct dentry *de,
			const char *symname)
{
        const char *name = de->d_name.name;
	int len = de->d_name.len;
	int symlen;
	int error = 0;

	lock_kernel();

	if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) {
		unlock_kernel();
		return -EPERM;
	}

	symlen = strlen(symname);
	if ( symlen > CODA_MAXPATHLEN ) {
		unlock_kernel();
		return -ENAMETOOLONG;
	}

	/*
	 * This entry is now negative. Since we do not create
	 * an inode for the entry we have to drop it.
	 */
	d_drop(de);
	error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
			      symname, symlen);

	/* mtime is no good anymore */
	if ( !error )
		coda_dir_update_mtime(dir_inode);

	unlock_kernel();
	return error;
}

/* destruction routines: unlink, rmdir */
static int coda_unlink(struct inode *dir, struct dentry *de)
{
        int error;
	const char *name = de->d_name.name;
	int len = de->d_name.len;

	lock_kernel();

	error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
	if ( error ) {
		unlock_kernel();
		return error;
	}

	coda_dir_update_mtime(dir);
	drop_nlink(de->d_inode);
	unlock_kernel();
	return 0;
}

static int coda_rmdir(struct inode *dir, struct dentry *de)
{
	const char *name = de->d_name.name;
	int len = de->d_name.len;
	int error;

	lock_kernel();

	error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
	if (!error) {
		/* VFS may delete the child */
		if (de->d_inode)
		    de->d_inode->i_nlink = 0;

		/* fix the link count of the parent */
		coda_dir_drop_nlink(dir);
		coda_dir_update_mtime(dir);
	}
	unlock_kernel();
	return error;
}

/* rename */
static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
		       struct inode *new_dir, struct dentry *new_dentry)
{
	const char *old_name = old_dentry->d_name.name;
	const char *new_name = new_dentry->d_name.name;
	int old_length = old_dentry->d_name.len;
	int new_length = new_dentry->d_name.len;
	int error;

	lock_kernel();

	error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
			     coda_i2f(new_dir), old_length, new_length,
			     (const char *) old_name, (const char *)new_name);

	if ( !error ) {
		if ( new_dentry->d_inode ) {
			if ( S_ISDIR(new_dentry->d_inode->i_mode) ) {
				coda_dir_drop_nlink(old_dir);
				coda_dir_inc_nlink(new_dir);
			}
			coda_dir_update_mtime(old_dir);
			coda_dir_update_mtime(new_dir);
			coda_flag_inode(new_dentry->d_inode, C_VATTR);
		} else {
			coda_flag_inode(old_dir, C_VATTR);
			coda_flag_inode(new_dir, C_VATTR);
		}
	}
	unlock_kernel();

	return error;
}


/* file operations for directories */
static int coda_readdir(struct file *coda_file, void *buf, filldir_t filldir)
{
	struct coda_file_info *cfi;
	struct file *host_file;
	int ret;

	cfi = CODA_FTOC(coda_file);
	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
	host_file = cfi->cfi_container;

	if (!host_file->f_op)
		return -ENOTDIR;

	if (host_file->f_op->readdir)
	{
		/* potemkin case: we were handed a directory inode.
		 * We can't use vfs_readdir because we have to keep the file
		 * position in sync between the coda_file and the host_file.
		 * and as such we need grab the inode mutex. */
		struct inode *host_inode = host_file->f_path.dentry->d_inode;

		mutex_lock(&host_inode->i_mutex);
		host_file->f_pos = coda_file->f_pos;

		ret = -ENOENT;
		if (!IS_DEADDIR(host_inode)) {
			ret = host_file->f_op->readdir(host_file, buf, filldir);
			file_accessed(host_file);
		}

		coda_file->f_pos = host_file->f_pos;
		mutex_unlock(&host_inode->i_mutex);
	}
	else /* Venus: we must read Venus dirents from a file */
		ret = coda_venus_readdir(coda_file, buf, filldir);

	return ret;
}

static inline unsigned int CDT2DT(unsigned char cdt)
{
	unsigned int dt;

	switch(cdt) {
	case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
	case CDT_FIFO:	  dt = DT_FIFO;    break;
	case CDT_CHR:	  dt = DT_CHR;     break;
	case CDT_DIR:	  dt = DT_DIR;     break;
	case CDT_BLK:	  dt = DT_BLK;     break;
	case CDT_REG:	  dt = DT_REG;     break;
	case CDT_LNK:	  dt = DT_LNK;     break;
	case CDT_SOCK:	  dt = DT_SOCK;    break;
	case CDT_WHT:	  dt = DT_WHT;     break;
	default:	  dt = DT_UNKNOWN; break;
	}
	return dt;
}

/* support routines */
static int coda_venus_readdir(struct file *coda_file, void *buf,
			      filldir_t filldir)
{
	int result = 0; /* # of entries returned */
	struct coda_file_info *cfi;
	struct coda_inode_info *cii;
	struct file *host_file;
	struct dentry *de;
	struct venus_dirent *vdir;
	unsigned long vdir_size =
	    (unsigned long)(&((struct venus_dirent *)0)->d_name);
	unsigned int type;
	struct qstr name;
	ino_t ino;
	int ret;

	cfi = CODA_FTOC(coda_file);
	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
	host_file = cfi->cfi_container;

	de = coda_file->f_path.dentry;
	cii = ITOC(de->d_inode);

	vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
	if (!vdir) return -ENOMEM;

	if (coda_file->f_pos == 0) {
		ret = filldir(buf, ".", 1, 0, de->d_inode->i_ino, DT_DIR);
		if (ret < 0)
			goto out;
		result++;
		coda_file->f_pos++;
	}
	if (coda_file->f_pos == 1) {
		ret = filldir(buf, "..", 2, 1, de->d_parent->d_inode->i_ino, DT_DIR);
		if (ret < 0)
			goto out;
		result++;
		coda_file->f_pos++;
	}
	while (1) {
		/* read entries from the directory file */
		ret = kernel_read(host_file, coda_file->f_pos - 2, (char *)vdir,
				  sizeof(*vdir));
		if (ret < 0) {
			printk(KERN_ERR "coda readdir: read dir %s failed %d\n",
			       coda_f2s(&cii->c_fid), ret);
			break;
		}
		if (ret == 0) break; /* end of directory file reached */

		/* catch truncated reads */
		if (ret < vdir_size || ret < vdir_size + vdir->d_namlen) {
			printk(KERN_ERR "coda readdir: short read on %s\n",
			       coda_f2s(&cii->c_fid));
			ret = -EBADF;
			break;
		}
		/* validate whether the directory file actually makes sense */
		if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
			printk(KERN_ERR "coda readdir: invalid dir %s\n",
			       coda_f2s(&cii->c_fid));
			ret = -EBADF;
			break;
		}

		name.len = vdir->d_namlen;
		name.name = vdir->d_name;

		/* Make sure we skip '.' and '..', we already got those */
		if (name.name[0] == '.' && (name.len == 1 ||
		    (vdir->d_name[1] == '.' && name.len == 2)))
			vdir->d_fileno = name.len = 0;

		/* skip null entries */
		if (vdir->d_fileno && name.len) {
			/* try to look up this entry in the dcache, that way
			 * userspace doesn't have to worry about breaking
			 * getcwd by having mismatched inode numbers for
			 * internal volume mountpoints. */
			ino = find_inode_number(de, &name);
			if (!ino) ino = vdir->d_fileno;

			type = CDT2DT(vdir->d_type);
			ret = filldir(buf, name.name, name.len,
				      coda_file->f_pos, ino, type);
			/* failure means no space for filling in this round */
			if (ret < 0) break;
			result++;
		}
		/* we'll always have progress because d_reclen is unsigned and
		 * we've already established it is non-zero. */
		coda_file->f_pos += vdir->d_reclen;
	}
out:
	kfree(vdir);
	return result ? result : ret;
}

/* called when a cache lookup succeeds */
static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd)
{
	struct inode *inode = de->d_inode;
	struct coda_inode_info *cii;

	if (!inode)
		return 1;
	lock_kernel();
	if (coda_isroot(inode))
		goto out;
	if (is_bad_inode(inode))
		goto bad;

	cii = ITOC(de->d_inode);
	if (!(cii->c_flags & (C_PURGE | C_FLUSH)))
		goto out;

	shrink_dcache_parent(de);

	/* propagate for a flush */
	if (cii->c_flags & C_FLUSH) 
		coda_flag_inode_children(inode, C_FLUSH);

	if (atomic_read(&de->d_count) > 1)
		/* pretend it's valid, but don't change the flags */
		goto out;

	/* clear the flags. */
	cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);

bad:
	unlock_kernel();
	return 0;
out:
	unlock_kernel();
	return 1;
}

/*
 * This is the callback from dput() when d_count is going to 0.
 * We use this to unhash dentries with bad inodes.
 */
static int coda_dentry_delete(struct dentry * dentry)
{
	int flags;

	if (!dentry->d_inode) 
		return 0;

	flags = (ITOC(dentry->d_inode)->c_flags) & C_PURGE;
	if (is_bad_inode(dentry->d_inode) || flags) {
		return 1;
	}
	return 0;
}


/*
 * This is called when we want to check if the inode has
 * changed on the server.  Coda makes this easy since the
 * cache manager Venus issues a downcall to the kernel when this 
 * happens 
 */
int coda_revalidate_inode(struct dentry *dentry)
{
	struct coda_vattr attr;
	int error = 0;
	int old_mode;
	ino_t old_ino;
	struct inode *inode = dentry->d_inode;
	struct coda_inode_info *cii = ITOC(inode);

	lock_kernel();
	if ( !cii->c_flags )
		goto ok;

	if (cii->c_flags & (C_VATTR | C_PURGE | C_FLUSH)) {
		error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
		if ( error )
			goto return_bad;

		/* this inode may be lost if:
		   - it's ino changed 
		   - type changes must be permitted for repair and
		   missing mount points.
		*/
		old_mode = inode->i_mode;
		old_ino = inode->i_ino;
		coda_vattr_to_iattr(inode, &attr);

		if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
			printk("Coda: inode %ld, fid %s changed type!\n",
			       inode->i_ino, coda_f2s(&(cii->c_fid)));
		}

		/* the following can happen when a local fid is replaced 
		   with a global one, here we lose and declare the inode bad */
		if (inode->i_ino != old_ino)
			goto return_bad;
		
		coda_flag_inode_children(inode, C_FLUSH);
		cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
	}

ok:
	unlock_kernel();
	return 0;

return_bad:
	unlock_kernel();
	return -EIO;
}
Commit	Line	Data
1da177e4 LT	1
	2	/*
	3	* Directory operations for Coda filesystem
	4	* Original version: (C) 1996 P. Braam and M. Callahan
	5	* Rewritten for Linux 2.1. (C) 1997 Carnegie Mellon University
	6	*
	7	* Carnegie Mellon encourages users to contribute improvements to
	8	* the Coda project. Contact Peter Braam (coda@cs.cmu.edu).
	9	*/
	10
	11	#include <linux/types.h>
	12	#include <linux/kernel.h>
	13	#include <linux/time.h>
	14	#include <linux/fs.h>
5a0e3ad6	15	#include <linux/slab.h>
1da177e4 LT	16	#include <linux/file.h>
	17	#include <linux/stat.h>
	18	#include <linux/errno.h>
	19	#include <linux/string.h>
	20	#include <linux/smp_lock.h>
	21
	22	#include <asm/uaccess.h>
	23
	24	#include <linux/coda.h>
	25	#include <linux/coda_linux.h>
	26	#include <linux/coda_psdev.h>
	27	#include <linux/coda_fs_i.h>
	28	#include <linux/coda_cache.h>
1da177e4	29
c98d8cfb AB	30	#include "coda_int.h"
c98d8cfb AB	31
1da177e4 LT	32	/* dir inode-ops */
	33	static int coda_create(struct inode dir, struct dentry new, int mode, struct nameidata *nd);
	34	static struct dentry coda_lookup(struct inode dir, struct dentry target, struct nameidata nd);
	35	static int coda_link(struct dentry old_dentry, struct inode dir_inode,
	36	struct dentry *entry);
	37	static int coda_unlink(struct inode dir_inode, struct dentry entry);
	38	static int coda_symlink(struct inode dir_inode, struct dentry entry,
	39	const char *symname);
	40	static int coda_mkdir(struct inode dir_inode, struct dentry entry, int mode);
	41	static int coda_rmdir(struct inode dir_inode, struct dentry entry);
	42	static int coda_rename(struct inode old_inode, struct dentry old_dentry,
	43	struct inode new_inode, struct dentry new_dentry);
	44
	45	/* dir file-ops */
97875253	46	static int coda_readdir(struct file file, void buf, filldir_t filldir);
1da177e4 LT	47
	48	/* dentry ops */
	49	static int coda_dentry_revalidate(struct dentry de, struct nameidata nd);
	50	static int coda_dentry_delete(struct dentry *);
	51
	52	/* support routines */
97875253 JH	53	static int coda_venus_readdir(struct file coda_file, void buf,
97875253 JH	54	filldir_t filldir);
1da177e4 LT	55
	56	/* same as fs/bad_inode.c */
	57	static int coda_return_EIO(void)
	58	{
	59	return -EIO;
	60	}
	61	#define CODA_EIO_ERROR ((void *) (coda_return_EIO))
	62
e16404ed	63	static const struct dentry_operations coda_dentry_operations =
1da177e4 LT	64	{
	65	.d_revalidate = coda_dentry_revalidate,
	66	.d_delete = coda_dentry_delete,
	67	};
	68
754661f1	69	const struct inode_operations coda_dir_inode_operations =
1da177e4 LT	70	{
	71	.create = coda_create,
	72	.lookup = coda_lookup,
	73	.link = coda_link,
	74	.unlink = coda_unlink,
	75	.symlink = coda_symlink,
	76	.mkdir = coda_mkdir,
	77	.rmdir = coda_rmdir,
	78	.mknod = CODA_EIO_ERROR,
	79	.rename = coda_rename,
	80	.permission = coda_permission,
	81	.getattr = coda_getattr,
	82	.setattr = coda_setattr,
	83	};
	84
4b6f5d20	85	const struct file_operations coda_dir_operations = {
1da177e4 LT	86	.llseek = generic_file_llseek,
	87	.read = generic_read_dir,
	88	.readdir = coda_readdir,
	89	.open = coda_open,
1da177e4 LT	90	.release = coda_release,
	91	.fsync = coda_fsync,
	92	};
	93
	94
	95	/* inode operations for directories */
	96	/* access routines: lookup, readlink, permission */
	97	static struct dentry coda_lookup(struct inode dir, struct dentry entry, struct nameidata nd)
	98	{
ed36f723	99	struct inode *inode = NULL;
1da177e4	100	struct CodaFid resfid = { { 0, } };
1da177e4 LT	101	int type = 0;
	102	int error = 0;
	103	const char *name = entry->d_name.name;
	104	size_t length = entry->d_name.len;
ed36f723 JH	105
	106	if (length > CODA_MAXNAMLEN) {
	107	printk(KERN_ERR "name too long: lookup, %s (%*s)\n",
1da177e4 LT	108	coda_i2s(dir), (int)length, name);
	109	return ERR_PTR(-ENAMETOOLONG);
	110	}
	111
ed36f723 JH	112	/* control object, create inode on the fly */
	113	if (coda_isroot(dir) && coda_iscontrol(name, length)) {
	114	error = coda_cnode_makectl(&inode, dir->i_sb);
	115	type = CODA_NOCACHE;
	116	goto exit;
	117	}
	118
1da177e4	119	lock_kernel();
ed36f723 JH	120
	121	error = venus_lookup(dir->i_sb, coda_i2f(dir), name, length,
	122	&type, &resfid);
	123	if (!error)
	124	error = coda_cnode_make(&inode, &resfid, dir->i_sb);
	125
	126	unlock_kernel();
	127
	128	if (error && error != -ENOENT)
1da177e4	129	return ERR_PTR(error);
1da177e4 LT	130
1da177e4 LT	131	exit:
1da177e4	132	entry->d_op = &coda_dentry_operations;
ed36f723 JH	133
	134	if (inode && (type & CODA_NOCACHE))
	135	coda_flag_inode(inode, C_VATTR \| C_PURGE);
	136
	137	return d_splice_alias(inode, entry);
1da177e4 LT	138	}
	139
	140
e6305c43	141	int coda_permission(struct inode *inode, int mask)
1da177e4 LT	142	{
1da177e4 LT	143	int error = 0;
e6305c43 AV	144
e6305c43 AV	145	mask &= MAY_READ \| MAY_WRITE \| MAY_EXEC;
1da177e4 LT	146
	147	if (!mask)
	148	return 0;
	149
f696a365 MS	150	if ((mask & MAY_EXEC) && !execute_ok(inode))
	151	return -EACCES;
	152
1da177e4 LT	153	lock_kernel();
1da177e4 LT	154
1da177e4 LT	155	if (coda_cache_check(inode, mask))
	156	goto out;
	157
	158	error = venus_access(inode->i_sb, coda_i2f(inode), mask);
	159
	160	if (!error)
	161	coda_cache_enter(inode, mask);
	162
	163	out:
	164	unlock_kernel();
d728900c	165	return error;
1da177e4 LT	166	}
	167
	168
d728900c	169	static inline void coda_dir_update_mtime(struct inode *dir)
1da177e4 LT	170	{
	171	#ifdef REQUERY_VENUS_FOR_MTIME
	172	/* invalidate the directory cnode's attributes so we refetch the
	173	* attributes from venus next time the inode is referenced */
	174	coda_flag_inode(dir, C_VATTR);
	175	#else
	176	/* optimistically we can also act as if our nose bleeds. The
d728900c JH	177	* granularity of the mtime is coarse anyways so we might actually be
d728900c JH	178	* right most of the time. Note: we only do this for directories. */
1da177e4 LT	179	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
1da177e4 LT	180	#endif
d728900c JH	181	}
	182
	183	/* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
	184	* trick to fool GNU find's optimizations. If we can't be sure of the link
	185	* (because of volume mount points) we set i_nlink to 1 which forces find
	186	* to consider every child as a possible directory. We should also never
	187	* see an increment or decrement for deleted directories where i_nlink == 0 */
	188	static inline void coda_dir_inc_nlink(struct inode *dir)
	189	{
	190	if (dir->i_nlink >= 2)
	191	inc_nlink(dir);
	192	}
	193
	194	static inline void coda_dir_drop_nlink(struct inode *dir)
	195	{
	196	if (dir->i_nlink > 2)
	197	drop_nlink(dir);
1da177e4 LT	198	}
	199
	200	/* creation routines: create, mknod, mkdir, link, symlink */
	201	static int coda_create(struct inode dir, struct dentry de, int mode, struct nameidata *nd)
	202	{
	203	int error=0;
	204	const char *name=de->d_name.name;
	205	int length=de->d_name.len;
	206	struct inode *inode;
	207	struct CodaFid newfid;
	208	struct coda_vattr attrs;
	209
	210	lock_kernel();
1da177e4 LT	211
	212	if (coda_isroot(dir) && coda_iscontrol(name, length)) {
	213	unlock_kernel();
	214	return -EPERM;
	215	}
	216
	217	error = venus_create(dir->i_sb, coda_i2f(dir), name, length,
	218	0, mode, &newfid, &attrs);
	219
	220	if ( error ) {
	221	unlock_kernel();
	222	d_drop(de);
	223	return error;
	224	}
	225
	226	inode = coda_iget(dir->i_sb, &newfid, &attrs);
	227	if ( IS_ERR(inode) ) {
	228	unlock_kernel();
	229	d_drop(de);
	230	return PTR_ERR(inode);
	231	}
	232
	233	/* invalidate the directory cnode's attributes */
d728900c	234	coda_dir_update_mtime(dir);
1da177e4 LT	235	unlock_kernel();
1da177e4 LT	236	d_instantiate(de, inode);
d728900c	237	return 0;
1da177e4 LT	238	}
	239
	240	static int coda_mkdir(struct inode dir, struct dentry de, int mode)
	241	{
	242	struct inode *inode;
	243	struct coda_vattr attrs;
	244	const char *name = de->d_name.name;
	245	int len = de->d_name.len;
	246	int error;
	247	struct CodaFid newfid;
	248
	249	lock_kernel();
1da177e4 LT	250
	251	if (coda_isroot(dir) && coda_iscontrol(name, len)) {
	252	unlock_kernel();
	253	return -EPERM;
	254	}
	255
	256	attrs.va_mode = mode;
	257	error = venus_mkdir(dir->i_sb, coda_i2f(dir),
	258	name, len, &newfid, &attrs);
	259
	260	if ( error ) {
	261	unlock_kernel();
	262	d_drop(de);
	263	return error;
	264	}
	265
	266	inode = coda_iget(dir->i_sb, &newfid, &attrs);
	267	if ( IS_ERR(inode) ) {
	268	unlock_kernel();
	269	d_drop(de);
	270	return PTR_ERR(inode);
	271	}
d728900c	272
1da177e4	273	/* invalidate the directory cnode's attributes */
d728900c JH	274	coda_dir_inc_nlink(dir);
d728900c JH	275	coda_dir_update_mtime(dir);
1da177e4 LT	276	unlock_kernel();
1da177e4 LT	277	d_instantiate(de, inode);
d728900c	278	return 0;
1da177e4 LT	279	}
	280
	281	/* try to make de an entry in dir_inodde linked to source_de */
	282	static int coda_link(struct dentry source_de, struct inode dir_inode,
	283	struct dentry *de)
	284	{
	285	struct inode *inode = source_de->d_inode;
	286	const char * name = de->d_name.name;
	287	int len = de->d_name.len;
	288	int error;
	289
	290	lock_kernel();
1da177e4 LT	291
	292	if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) {
	293	unlock_kernel();
	294	return -EPERM;
	295	}
	296
	297	error = venus_link(dir_inode->i_sb, coda_i2f(inode),
	298	coda_i2f(dir_inode), (const char *)name, len);
	299
d728900c	300	if (error) {
1da177e4 LT	301	d_drop(de);
	302	goto out;
	303	}
	304
d728900c	305	coda_dir_update_mtime(dir_inode);
1da177e4 LT	306	atomic_inc(&inode->i_count);
1da177e4 LT	307	d_instantiate(de, inode);
d8c76e6f	308	inc_nlink(inode);
d728900c	309
1da177e4 LT	310	out:
	311	unlock_kernel();
	312	return(error);
	313	}
	314
	315
	316	static int coda_symlink(struct inode dir_inode, struct dentry de,
	317	const char *symname)
	318	{
	319	const char *name = de->d_name.name;
	320	int len = de->d_name.len;
	321	int symlen;
3cf01f28 JH	322	int error = 0;
3cf01f28 JH	323
1da177e4	324	lock_kernel();
1da177e4 LT	325
	326	if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) {
	327	unlock_kernel();
	328	return -EPERM;
	329	}
	330
	331	symlen = strlen(symname);
	332	if ( symlen > CODA_MAXPATHLEN ) {
	333	unlock_kernel();
	334	return -ENAMETOOLONG;
	335	}
	336
	337	/*
	338	* This entry is now negative. Since we do not create
d728900c	339	* an inode for the entry we have to drop it.
1da177e4 LT	340	*/
1da177e4 LT	341	d_drop(de);
d728900c	342	error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
1da177e4 LT	343	symname, symlen);
	344
	345	/* mtime is no good anymore */
	346	if ( !error )
d728900c	347	coda_dir_update_mtime(dir_inode);
1da177e4 LT	348
1da177e4 LT	349	unlock_kernel();
d728900c	350	return error;
1da177e4 LT	351	}
	352
	353	/* destruction routines: unlink, rmdir */
9fe76c76	354	static int coda_unlink(struct inode dir, struct dentry de)
1da177e4 LT	355	{
	356	int error;
	357	const char *name = de->d_name.name;
	358	int len = de->d_name.len;
	359
	360	lock_kernel();
1da177e4	361
d728900c JH	362	error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
d728900c JH	363	if ( error ) {
1da177e4	364	unlock_kernel();
d728900c JH	365	return error;
d728900c JH	366	}
1da177e4	367
d728900c	368	coda_dir_update_mtime(dir);
9a53c3a7	369	drop_nlink(de->d_inode);
1da177e4	370	unlock_kernel();
d728900c	371	return 0;
1da177e4 LT	372	}
1da177e4 LT	373
9fe76c76	374	static int coda_rmdir(struct inode dir, struct dentry de)
1da177e4 LT	375	{
	376	const char *name = de->d_name.name;
	377	int len = de->d_name.len;
8c6d2152	378	int error;
1da177e4 LT	379
1da177e4 LT	380	lock_kernel();
1da177e4	381
1da177e4	382	error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
8c6d2152 JH	383	if (!error) {
	384	/* VFS may delete the child */
	385	if (de->d_inode)
	386	de->d_inode->i_nlink = 0;
1da177e4	387
8c6d2152 JH	388	/* fix the link count of the parent */
	389	coda_dir_drop_nlink(dir);
	390	coda_dir_update_mtime(dir);
d728900c	391	}
1da177e4	392	unlock_kernel();
8c6d2152	393	return error;
1da177e4 LT	394	}
	395
	396	/* rename */
d728900c	397	static int coda_rename(struct inode old_dir, struct dentry old_dentry,
1da177e4 LT	398	struct inode new_dir, struct dentry new_dentry)
1da177e4 LT	399	{
d728900c JH	400	const char *old_name = old_dentry->d_name.name;
d728900c JH	401	const char *new_name = new_dentry->d_name.name;
1da177e4 LT	402	int old_length = old_dentry->d_name.len;
1da177e4 LT	403	int new_length = new_dentry->d_name.len;
d728900c	404	int error;
1da177e4 LT	405
1da177e4 LT	406	lock_kernel();
1da177e4	407
d728900c JH	408	error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
d728900c JH	409	coda_i2f(new_dir), old_length, new_length,
1da177e4 LT	410	(const char ) old_name, (const char )new_name);
1da177e4 LT	411
d728900c	412	if ( !error ) {
1da177e4	413	if ( new_dentry->d_inode ) {
d728900c JH	414	if ( S_ISDIR(new_dentry->d_inode->i_mode) ) {
	415	coda_dir_drop_nlink(old_dir);
	416	coda_dir_inc_nlink(new_dir);
	417	}
	418	coda_dir_update_mtime(old_dir);
	419	coda_dir_update_mtime(new_dir);
1da177e4 LT	420	coda_flag_inode(new_dentry->d_inode, C_VATTR);
	421	} else {
	422	coda_flag_inode(old_dir, C_VATTR);
	423	coda_flag_inode(new_dir, C_VATTR);
d728900c	424	}
1da177e4 LT	425	}
	426	unlock_kernel();
	427
	428	return error;
	429	}
	430
	431
	432	/* file operations for directories */
9fe76c76	433	static int coda_readdir(struct file coda_file, void buf, filldir_t filldir)
1da177e4	434	{
1da177e4 LT	435	struct coda_file_info *cfi;
1da177e4 LT	436	struct file *host_file;
1da177e4 LT	437	int ret;
	438
	439	cfi = CODA_FTOC(coda_file);
	440	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	441	host_file = cfi->cfi_container;
	442
97875253 JH	443	if (!host_file->f_op)
	444	return -ENOTDIR;
	445
	446	if (host_file->f_op->readdir)
	447	{
	448	/* potemkin case: we were handed a directory inode.
	449	* We can't use vfs_readdir because we have to keep the file
	450	* position in sync between the coda_file and the host_file.
	451	* and as such we need grab the inode mutex. */
	452	struct inode *host_inode = host_file->f_path.dentry->d_inode;
	453
	454	mutex_lock(&host_inode->i_mutex);
	455	host_file->f_pos = coda_file->f_pos;
1da177e4 LT	456
	457	ret = -ENOENT;
	458	if (!IS_DEADDIR(host_inode)) {
97875253	459	ret = host_file->f_op->readdir(host_file, buf, filldir);
1da177e4 LT	460	file_accessed(host_file);
1da177e4 LT	461	}
97875253 JH	462
	463	coda_file->f_pos = host_file->f_pos;
	464	mutex_unlock(&host_inode->i_mutex);
1da177e4	465	}
97875253 JH	466	else /* Venus: we must read Venus dirents from a file */
97875253 JH	467	ret = coda_venus_readdir(coda_file, buf, filldir);
1da177e4 LT	468
	469	return ret;
	470	}
	471
	472	static inline unsigned int CDT2DT(unsigned char cdt)
	473	{
	474	unsigned int dt;
	475
	476	switch(cdt) {
	477	case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
	478	case CDT_FIFO: dt = DT_FIFO; break;
	479	case CDT_CHR: dt = DT_CHR; break;
	480	case CDT_DIR: dt = DT_DIR; break;
	481	case CDT_BLK: dt = DT_BLK; break;
	482	case CDT_REG: dt = DT_REG; break;
	483	case CDT_LNK: dt = DT_LNK; break;
	484	case CDT_SOCK: dt = DT_SOCK; break;
	485	case CDT_WHT: dt = DT_WHT; break;
	486	default: dt = DT_UNKNOWN; break;
	487	}
	488	return dt;
	489	}
	490
	491	/* support routines */
97875253 JH	492	static int coda_venus_readdir(struct file coda_file, void buf,
97875253 JH	493	filldir_t filldir)
1da177e4 LT	494	{
1da177e4 LT	495	int result = 0; /* # of entries returned */
97875253 JH	496	struct coda_file_info *cfi;
	497	struct coda_inode_info *cii;
	498	struct file *host_file;
	499	struct dentry *de;
1da177e4 LT	500	struct venus_dirent *vdir;
	501	unsigned long vdir_size =
	502	(unsigned long)(&((struct venus_dirent *)0)->d_name);
	503	unsigned int type;
	504	struct qstr name;
	505	ino_t ino;
97875253 JH	506	int ret;
	507
	508	cfi = CODA_FTOC(coda_file);
	509	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	510	host_file = cfi->cfi_container;
	511
	512	de = coda_file->f_path.dentry;
	513	cii = ITOC(de->d_inode);
1da177e4	514
f52720ca	515	vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
1da177e4 LT	516	if (!vdir) return -ENOMEM;
1da177e4 LT	517
5f47c7ea	518	if (coda_file->f_pos == 0) {
97875253	519	ret = filldir(buf, ".", 1, 0, de->d_inode->i_ino, DT_DIR);
5f47c7ea AV	520	if (ret < 0)
5f47c7ea AV	521	goto out;
1da177e4	522	result++;
97875253	523	coda_file->f_pos++;
5f47c7ea AV	524	}
5f47c7ea AV	525	if (coda_file->f_pos == 1) {
97875253	526	ret = filldir(buf, "..", 2, 1, de->d_parent->d_inode->i_ino, DT_DIR);
5f47c7ea AV	527	if (ret < 0)
5f47c7ea AV	528	goto out;
1da177e4	529	result++;
97875253	530	coda_file->f_pos++;
5f47c7ea	531	}
1da177e4 LT	532	while (1) {
1da177e4 LT	533	/* read entries from the directory file */
97875253	534	ret = kernel_read(host_file, coda_file->f_pos - 2, (char *)vdir,
1da177e4 LT	535	sizeof(*vdir));
1da177e4 LT	536	if (ret < 0) {
97875253 JH	537	printk(KERN_ERR "coda readdir: read dir %s failed %d\n",
97875253 JH	538	coda_f2s(&cii->c_fid), ret);
1da177e4 LT	539	break;
	540	}
	541	if (ret == 0) break; /* end of directory file reached */
	542
	543	/* catch truncated reads */
	544	if (ret < vdir_size \|\| ret < vdir_size + vdir->d_namlen) {
97875253 JH	545	printk(KERN_ERR "coda readdir: short read on %s\n",
97875253 JH	546	coda_f2s(&cii->c_fid));
1da177e4 LT	547	ret = -EBADF;
	548	break;
	549	}
	550	/* validate whether the directory file actually makes sense */
	551	if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
97875253 JH	552	printk(KERN_ERR "coda readdir: invalid dir %s\n",
97875253 JH	553	coda_f2s(&cii->c_fid));
1da177e4 LT	554	ret = -EBADF;
	555	break;
	556	}
	557
	558	name.len = vdir->d_namlen;
	559	name.name = vdir->d_name;
	560
	561	/* Make sure we skip '.' and '..', we already got those */
	562	if (name.name[0] == '.' && (name.len == 1 \|\|
	563	(vdir->d_name[1] == '.' && name.len == 2)))
	564	vdir->d_fileno = name.len = 0;
	565
	566	/* skip null entries */
	567	if (vdir->d_fileno && name.len) {
	568	/* try to look up this entry in the dcache, that way
	569	* userspace doesn't have to worry about breaking
	570	* getcwd by having mismatched inode numbers for
	571	* internal volume mountpoints. */
97875253	572	ino = find_inode_number(de, &name);
1da177e4 LT	573	if (!ino) ino = vdir->d_fileno;
	574
	575	type = CDT2DT(vdir->d_type);
97875253 JH	576	ret = filldir(buf, name.name, name.len,
97875253 JH	577	coda_file->f_pos, ino, type);
1da177e4 LT	578	/* failure means no space for filling in this round */
	579	if (ret < 0) break;
	580	result++;
	581	}
	582	/* we'll always have progress because d_reclen is unsigned and
	583	* we've already established it is non-zero. */
97875253 JH	584	coda_file->f_pos += vdir->d_reclen;
97875253 JH	585	}
5f47c7ea	586	out:
1da177e4 LT	587	kfree(vdir);
	588	return result ? result : ret;
	589	}
	590
	591	/* called when a cache lookup succeeds */
	592	static int coda_dentry_revalidate(struct dentry de, struct nameidata nd)
	593	{
	594	struct inode *inode = de->d_inode;
	595	struct coda_inode_info *cii;
	596
	597	if (!inode)
	598	return 1;
	599	lock_kernel();
	600	if (coda_isroot(inode))
	601	goto out;
	602	if (is_bad_inode(inode))
	603	goto bad;
	604
	605	cii = ITOC(de->d_inode);
	606	if (!(cii->c_flags & (C_PURGE \| C_FLUSH)))
	607	goto out;
	608
	609	shrink_dcache_parent(de);
	610
	611	/* propagate for a flush */
	612	if (cii->c_flags & C_FLUSH)
	613	coda_flag_inode_children(inode, C_FLUSH);
	614
	615	if (atomic_read(&de->d_count) > 1)
	616	/* pretend it's valid, but don't change the flags */
	617	goto out;
	618
	619	/* clear the flags. */
	620	cii->c_flags &= ~(C_VATTR \| C_PURGE \| C_FLUSH);
	621
	622	bad:
	623	unlock_kernel();
	624	return 0;
	625	out:
	626	unlock_kernel();
	627	return 1;
	628	}
	629
	630	/*
	631	* This is the callback from dput() when d_count is going to 0.
	632	* We use this to unhash dentries with bad inodes.
	633	*/
	634	static int coda_dentry_delete(struct dentry * dentry)
	635	{
	636	int flags;
	637
	638	if (!dentry->d_inode)
	639	return 0;
	640
	641	flags = (ITOC(dentry->d_inode)->c_flags) & C_PURGE;
	642	if (is_bad_inode(dentry->d_inode) \|\| flags) {
	643	return 1;
	644	}
	645	return 0;
	646	}
	647
	648
	649
	650	/*
651	* This is called when we want to check if the inode has
652	* changed on the server. Coda makes this easy since the
653	* cache manager Venus issues a downcall to the kernel when this
654	* happens
655	*/
656	int coda_revalidate_inode(struct dentry *dentry)
657	{
658	struct coda_vattr attr;
659	int error = 0;
660	int old_mode;
661	ino_t old_ino;
662	struct inode *inode = dentry->d_inode;
663	struct coda_inode_info *cii = ITOC(inode);
664
665	lock_kernel();
666	if ( !cii->c_flags )
667	goto ok;
668
669	if (cii->c_flags & (C_VATTR \| C_PURGE \| C_FLUSH)) {
670	error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
671	if ( error )
672	goto return_bad;
673
674	/* this inode may be lost if:
675	- it's ino changed
676	- type changes must be permitted for repair and
677	missing mount points.
678	*/
679	old_mode = inode->i_mode;
680	old_ino = inode->i_ino;
681	coda_vattr_to_iattr(inode, &attr);
682
683	if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
684	printk("Coda: inode %ld, fid %s changed type!\n",
685	inode->i_ino, coda_f2s(&(cii->c_fid)));
686	}
687
688	/* the following can happen when a local fid is replaced
689	with a global one, here we lose and declare the inode bad */
690	if (inode->i_ino != old_ino)
691	goto return_bad;
692
693	coda_flag_inode_children(inode, C_FLUSH);
694	cii->c_flags &= ~(C_VATTR \| C_PURGE \| C_FLUSH);
695	}
696
697	ok:
698	unlock_kernel();
699	return 0;
700
701	return_bad:
702	unlock_kernel();
703	return -EIO;
704	}