[deliverable/linux.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/spinlock.h>
#include <linux/namei.h>

#include <asm/uaccess.h>

#include <linux/coda.h>
#include <linux/coda_psdev.h>
#include "coda_linux.h"
#include "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(const 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))

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;
	}

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

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

exit:
	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, unsigned int flags)
{
	int error;

	if (flags & IPERM_FLAG_RCU)
		return -ECHILD;

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

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

	if (coda_cache_check(inode, mask))
		return 0;

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

	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;
	const char *name=de->d_name.name;
	int length=de->d_name.len;
	struct inode *inode;
	struct CodaFid newfid;
	struct coda_vattr attrs;

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

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

	inode = coda_iget(dir->i_sb, &newfid, &attrs);
	if (IS_ERR(inode)) {
		error = PTR_ERR(inode);
		goto err_out;
	}

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

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;

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

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

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

/* 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;

	if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
		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);
		return error;
	}

	coda_dir_update_mtime(dir_inode);
	ihold(inode);
	d_instantiate(de, inode);
	inc_nlink(inode);
	return 0;
}


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;

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

	symlen = strlen(symname);
	if (symlen > CODA_MAXPATHLEN)
		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);

	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;

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

	coda_dir_update_mtime(dir);
	drop_nlink(de->d_inode);
	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;

	dentry_unhash(de);

	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);
	}
	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;

	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);
		}
	}
	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;
	struct coda_inode_info *cii;

	if (nd->flags & LOOKUP_RCU)
		return -ECHILD;

	inode = de->d_inode;
	if (!inode || 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 (de->d_count > 1)
		/* pretend it's valid, but don't change the flags */
		goto out;

	/* clear the flags. */
	spin_lock(&cii->c_lock);
	cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
	spin_unlock(&cii->c_lock);
bad:
	return 0;
out:
	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(const 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;
	int old_mode;
	ino_t old_ino;
	struct inode *inode = dentry->d_inode;
	struct coda_inode_info *cii = ITOC(inode);

	if (!cii->c_flags)
		return 0;

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

		/* 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)
			return -EIO;
		
		coda_flag_inode_children(inode, C_FLUSH);

		spin_lock(&cii->c_lock);
		cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
		spin_unlock(&cii->c_lock);
	}
	return 0;
}
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>
b5ce1d83	20	#include <linux/spinlock.h>
34286d66	21	#include <linux/namei.h>
1da177e4 LT	22
	23	#include <asm/uaccess.h>
	24
	25	#include <linux/coda.h>
1da177e4	26	#include <linux/coda_psdev.h>
31a203df AV	27	#include "coda_linux.h"
31a203df AV	28	#include "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);
fe15ce44	50	static int coda_dentry_delete(const struct dentry *);
1da177e4 LT	51
1da177e4 LT	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
9501e4c4	63	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
ed36f723 JH	119	error = venus_lookup(dir->i_sb, coda_i2f(dir), name, length,
	120	&type, &resfid);
	121	if (!error)
	122	error = coda_cnode_make(&inode, &resfid, dir->i_sb);
	123
ed36f723	124	if (error && error != -ENOENT)
1da177e4	125	return ERR_PTR(error);
1da177e4 LT	126
1da177e4 LT	127	exit:
ed36f723 JH	128	if (inode && (type & CODA_NOCACHE))
	129	coda_flag_inode(inode, C_VATTR \| C_PURGE);
	130
	131	return d_splice_alias(inode, entry);
1da177e4 LT	132	}
	133
	134
b74c79e9	135	int coda_permission(struct inode *inode, int mask, unsigned int flags)
1da177e4	136	{
f7cc02b8	137	int error;
e6305c43	138
b74c79e9 NP	139	if (flags & IPERM_FLAG_RCU)
	140	return -ECHILD;
	141
e6305c43	142	mask &= MAY_READ \| MAY_WRITE \| MAY_EXEC;
1da177e4 LT	143
1da177e4 LT	144	if (!mask)
f7cc02b8	145	return 0;
1da177e4	146
f696a365 MS	147	if ((mask & MAY_EXEC) && !execute_ok(inode))
	148	return -EACCES;
	149
1da177e4	150	if (coda_cache_check(inode, mask))
f7cc02b8	151	return 0;
1da177e4	152
f7cc02b8	153	error = venus_access(inode->i_sb, coda_i2f(inode), mask);
1da177e4 LT	154
	155	if (!error)
	156	coda_cache_enter(inode, mask);
	157
d728900c	158	return error;
1da177e4 LT	159	}
	160
	161
d728900c	162	static inline void coda_dir_update_mtime(struct inode *dir)
1da177e4 LT	163	{
	164	#ifdef REQUERY_VENUS_FOR_MTIME
	165	/* invalidate the directory cnode's attributes so we refetch the
	166	* attributes from venus next time the inode is referenced */
	167	coda_flag_inode(dir, C_VATTR);
	168	#else
	169	/* optimistically we can also act as if our nose bleeds. The
d728900c JH	170	* granularity of the mtime is coarse anyways so we might actually be
d728900c JH	171	* right most of the time. Note: we only do this for directories. */
1da177e4 LT	172	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
1da177e4 LT	173	#endif
d728900c JH	174	}
	175
	176	/* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
	177	* trick to fool GNU find's optimizations. If we can't be sure of the link
	178	* (because of volume mount points) we set i_nlink to 1 which forces find
	179	* to consider every child as a possible directory. We should also never
	180	* see an increment or decrement for deleted directories where i_nlink == 0 */
	181	static inline void coda_dir_inc_nlink(struct inode *dir)
	182	{
	183	if (dir->i_nlink >= 2)
	184	inc_nlink(dir);
	185	}
	186
	187	static inline void coda_dir_drop_nlink(struct inode *dir)
	188	{
	189	if (dir->i_nlink > 2)
	190	drop_nlink(dir);
1da177e4 LT	191	}
	192
	193	/* creation routines: create, mknod, mkdir, link, symlink */
	194	static int coda_create(struct inode dir, struct dentry de, int mode, struct nameidata *nd)
	195	{
f7cc02b8	196	int error;
1da177e4 LT	197	const char *name=de->d_name.name;
	198	int length=de->d_name.len;
	199	struct inode *inode;
	200	struct CodaFid newfid;
	201	struct coda_vattr attrs;
	202
f7cc02b8	203	if (coda_isroot(dir) && coda_iscontrol(name, length))
1da177e4	204	return -EPERM;
1da177e4 LT	205
	206	error = venus_create(dir->i_sb, coda_i2f(dir), name, length,
	207	0, mode, &newfid, &attrs);
f7cc02b8 YA	208	if (error)
f7cc02b8 YA	209	goto err_out;
1da177e4 LT	210
1da177e4 LT	211	inode = coda_iget(dir->i_sb, &newfid, &attrs);
f7cc02b8 YA	212	if (IS_ERR(inode)) {
	213	error = PTR_ERR(inode);
	214	goto err_out;
1da177e4 LT	215	}
	216
	217	/* invalidate the directory cnode's attributes */
d728900c	218	coda_dir_update_mtime(dir);
1da177e4	219	d_instantiate(de, inode);
d728900c	220	return 0;
f7cc02b8 YA	221	err_out:
	222	d_drop(de);
	223	return error;
1da177e4 LT	224	}
	225
	226	static int coda_mkdir(struct inode dir, struct dentry de, int mode)
	227	{
	228	struct inode *inode;
	229	struct coda_vattr attrs;
	230	const char *name = de->d_name.name;
	231	int len = de->d_name.len;
	232	int error;
	233	struct CodaFid newfid;
	234
f7cc02b8	235	if (coda_isroot(dir) && coda_iscontrol(name, len))
1da177e4	236	return -EPERM;
1da177e4 LT	237
	238	attrs.va_mode = mode;
	239	error = venus_mkdir(dir->i_sb, coda_i2f(dir),
	240	name, len, &newfid, &attrs);
f7cc02b8 YA	241	if (error)
f7cc02b8 YA	242	goto err_out;
1da177e4 LT	243
1da177e4 LT	244	inode = coda_iget(dir->i_sb, &newfid, &attrs);
f7cc02b8 YA	245	if (IS_ERR(inode)) {
	246	error = PTR_ERR(inode);
	247	goto err_out;
1da177e4	248	}
d728900c	249
1da177e4	250	/* invalidate the directory cnode's attributes */
d728900c JH	251	coda_dir_inc_nlink(dir);
d728900c JH	252	coda_dir_update_mtime(dir);
1da177e4	253	d_instantiate(de, inode);
d728900c	254	return 0;
f7cc02b8 YA	255	err_out:
	256	d_drop(de);
	257	return error;
1da177e4 LT	258	}
	259
	260	/* try to make de an entry in dir_inodde linked to source_de */
	261	static int coda_link(struct dentry source_de, struct inode dir_inode,
	262	struct dentry *de)
	263	{
	264	struct inode *inode = source_de->d_inode;
	265	const char * name = de->d_name.name;
	266	int len = de->d_name.len;
	267	int error;
	268
f7cc02b8	269	if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
1da177e4	270	return -EPERM;
1da177e4 LT	271
	272	error = venus_link(dir_inode->i_sb, coda_i2f(inode),
	273	coda_i2f(dir_inode), (const char *)name, len);
d728900c	274	if (error) {
1da177e4	275	d_drop(de);
f7cc02b8	276	return error;
1da177e4 LT	277	}
1da177e4 LT	278
d728900c	279	coda_dir_update_mtime(dir_inode);
7de9c6ee	280	ihold(inode);
1da177e4	281	d_instantiate(de, inode);
d8c76e6f	282	inc_nlink(inode);
f7cc02b8	283	return 0;
1da177e4 LT	284	}
	285
	286
	287	static int coda_symlink(struct inode dir_inode, struct dentry de,
	288	const char *symname)
	289	{
f7cc02b8	290	const char *name = de->d_name.name;
1da177e4 LT	291	int len = de->d_name.len;
1da177e4 LT	292	int symlen;
f7cc02b8	293	int error;
1da177e4	294
f7cc02b8	295	if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
1da177e4	296	return -EPERM;
1da177e4 LT	297
1da177e4 LT	298	symlen = strlen(symname);
f7cc02b8	299	if (symlen > CODA_MAXPATHLEN)
1da177e4	300	return -ENAMETOOLONG;
1da177e4 LT	301
	302	/*
	303	* This entry is now negative. Since we do not create
d728900c	304	* an inode for the entry we have to drop it.
1da177e4 LT	305	*/
1da177e4 LT	306	d_drop(de);
d728900c	307	error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
1da177e4 LT	308	symname, symlen);
	309
	310	/* mtime is no good anymore */
f7cc02b8	311	if (!error)
d728900c	312	coda_dir_update_mtime(dir_inode);
1da177e4	313
d728900c	314	return error;
1da177e4 LT	315	}
	316
	317	/* destruction routines: unlink, rmdir */
9fe76c76	318	static int coda_unlink(struct inode dir, struct dentry de)
1da177e4 LT	319	{
	320	int error;
	321	const char *name = de->d_name.name;
	322	int len = de->d_name.len;
	323
d728900c	324	error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
f7cc02b8	325	if (error)
d728900c	326	return error;
1da177e4	327
d728900c	328	coda_dir_update_mtime(dir);
9a53c3a7	329	drop_nlink(de->d_inode);
d728900c	330	return 0;
1da177e4 LT	331	}
1da177e4 LT	332
9fe76c76	333	static int coda_rmdir(struct inode dir, struct dentry de)
1da177e4 LT	334	{
	335	const char *name = de->d_name.name;
	336	int len = de->d_name.len;
8c6d2152	337	int error;
1da177e4	338
79bf7c73 SW	339	dentry_unhash(de);
79bf7c73 SW	340
1da177e4	341	error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
8c6d2152 JH	342	if (!error) {
	343	/* VFS may delete the child */
	344	if (de->d_inode)
	345	de->d_inode->i_nlink = 0;
1da177e4	346
8c6d2152 JH	347	/* fix the link count of the parent */
	348	coda_dir_drop_nlink(dir);
	349	coda_dir_update_mtime(dir);
d728900c	350	}
8c6d2152	351	return error;
1da177e4 LT	352	}
	353
	354	/* rename */
d728900c	355	static int coda_rename(struct inode old_dir, struct dentry old_dentry,
1da177e4 LT	356	struct inode new_dir, struct dentry new_dentry)
1da177e4 LT	357	{
d728900c JH	358	const char *old_name = old_dentry->d_name.name;
d728900c JH	359	const char *new_name = new_dentry->d_name.name;
1da177e4 LT	360	int old_length = old_dentry->d_name.len;
1da177e4 LT	361	int new_length = new_dentry->d_name.len;
d728900c	362	int error;
1da177e4	363
d728900c JH	364	error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
d728900c JH	365	coda_i2f(new_dir), old_length, new_length,
1da177e4	366	(const char ) old_name, (const char )new_name);
f7cc02b8 YA	367	if (!error) {
	368	if (new_dentry->d_inode) {
	369	if (S_ISDIR(new_dentry->d_inode->i_mode)) {
d728900c JH	370	coda_dir_drop_nlink(old_dir);
	371	coda_dir_inc_nlink(new_dir);
	372	}
	373	coda_dir_update_mtime(old_dir);
	374	coda_dir_update_mtime(new_dir);
1da177e4 LT	375	coda_flag_inode(new_dentry->d_inode, C_VATTR);
	376	} else {
	377	coda_flag_inode(old_dir, C_VATTR);
	378	coda_flag_inode(new_dir, C_VATTR);
d728900c	379	}
1da177e4	380	}
1da177e4 LT	381	return error;
	382	}
	383
	384
	385	/* file operations for directories */
9fe76c76	386	static int coda_readdir(struct file coda_file, void buf, filldir_t filldir)
1da177e4	387	{
1da177e4 LT	388	struct coda_file_info *cfi;
1da177e4 LT	389	struct file *host_file;
1da177e4 LT	390	int ret;
	391
	392	cfi = CODA_FTOC(coda_file);
	393	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	394	host_file = cfi->cfi_container;
	395
97875253 JH	396	if (!host_file->f_op)
	397	return -ENOTDIR;
	398
	399	if (host_file->f_op->readdir)
	400	{
	401	/* potemkin case: we were handed a directory inode.
	402	* We can't use vfs_readdir because we have to keep the file
	403	* position in sync between the coda_file and the host_file.
	404	* and as such we need grab the inode mutex. */
	405	struct inode *host_inode = host_file->f_path.dentry->d_inode;
	406
	407	mutex_lock(&host_inode->i_mutex);
	408	host_file->f_pos = coda_file->f_pos;
1da177e4 LT	409
	410	ret = -ENOENT;
	411	if (!IS_DEADDIR(host_inode)) {
97875253	412	ret = host_file->f_op->readdir(host_file, buf, filldir);
1da177e4 LT	413	file_accessed(host_file);
1da177e4 LT	414	}
97875253 JH	415
	416	coda_file->f_pos = host_file->f_pos;
	417	mutex_unlock(&host_inode->i_mutex);
1da177e4	418	}
97875253 JH	419	else /* Venus: we must read Venus dirents from a file */
97875253 JH	420	ret = coda_venus_readdir(coda_file, buf, filldir);
1da177e4 LT	421
	422	return ret;
	423	}
	424
	425	static inline unsigned int CDT2DT(unsigned char cdt)
	426	{
	427	unsigned int dt;
	428
	429	switch(cdt) {
	430	case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
	431	case CDT_FIFO: dt = DT_FIFO; break;
	432	case CDT_CHR: dt = DT_CHR; break;
	433	case CDT_DIR: dt = DT_DIR; break;
	434	case CDT_BLK: dt = DT_BLK; break;
	435	case CDT_REG: dt = DT_REG; break;
	436	case CDT_LNK: dt = DT_LNK; break;
	437	case CDT_SOCK: dt = DT_SOCK; break;
	438	case CDT_WHT: dt = DT_WHT; break;
	439	default: dt = DT_UNKNOWN; break;
	440	}
	441	return dt;
	442	}
	443
	444	/* support routines */
97875253 JH	445	static int coda_venus_readdir(struct file coda_file, void buf,
97875253 JH	446	filldir_t filldir)
1da177e4 LT	447	{
1da177e4 LT	448	int result = 0; /* # of entries returned */
97875253 JH	449	struct coda_file_info *cfi;
	450	struct coda_inode_info *cii;
	451	struct file *host_file;
	452	struct dentry *de;
1da177e4 LT	453	struct venus_dirent *vdir;
	454	unsigned long vdir_size =
	455	(unsigned long)(&((struct venus_dirent *)0)->d_name);
	456	unsigned int type;
	457	struct qstr name;
	458	ino_t ino;
97875253 JH	459	int ret;
	460
	461	cfi = CODA_FTOC(coda_file);
	462	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	463	host_file = cfi->cfi_container;
	464
	465	de = coda_file->f_path.dentry;
	466	cii = ITOC(de->d_inode);
1da177e4	467
f52720ca	468	vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
1da177e4 LT	469	if (!vdir) return -ENOMEM;
1da177e4 LT	470
5f47c7ea	471	if (coda_file->f_pos == 0) {
97875253	472	ret = filldir(buf, ".", 1, 0, de->d_inode->i_ino, DT_DIR);
5f47c7ea AV	473	if (ret < 0)
5f47c7ea AV	474	goto out;
1da177e4	475	result++;
97875253	476	coda_file->f_pos++;
5f47c7ea AV	477	}
5f47c7ea AV	478	if (coda_file->f_pos == 1) {
97875253	479	ret = filldir(buf, "..", 2, 1, de->d_parent->d_inode->i_ino, DT_DIR);
5f47c7ea AV	480	if (ret < 0)
5f47c7ea AV	481	goto out;
1da177e4	482	result++;
97875253	483	coda_file->f_pos++;
5f47c7ea	484	}
1da177e4 LT	485	while (1) {
1da177e4 LT	486	/* read entries from the directory file */
97875253	487	ret = kernel_read(host_file, coda_file->f_pos - 2, (char *)vdir,
1da177e4 LT	488	sizeof(*vdir));
1da177e4 LT	489	if (ret < 0) {
97875253 JH	490	printk(KERN_ERR "coda readdir: read dir %s failed %d\n",
97875253 JH	491	coda_f2s(&cii->c_fid), ret);
1da177e4 LT	492	break;
	493	}
	494	if (ret == 0) break; /* end of directory file reached */
	495
	496	/* catch truncated reads */
	497	if (ret < vdir_size \|\| ret < vdir_size + vdir->d_namlen) {
97875253 JH	498	printk(KERN_ERR "coda readdir: short read on %s\n",
97875253 JH	499	coda_f2s(&cii->c_fid));
1da177e4 LT	500	ret = -EBADF;
	501	break;
	502	}
	503	/* validate whether the directory file actually makes sense */
	504	if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
97875253 JH	505	printk(KERN_ERR "coda readdir: invalid dir %s\n",
97875253 JH	506	coda_f2s(&cii->c_fid));
1da177e4 LT	507	ret = -EBADF;
	508	break;
	509	}
	510
	511	name.len = vdir->d_namlen;
	512	name.name = vdir->d_name;
	513
	514	/* Make sure we skip '.' and '..', we already got those */
	515	if (name.name[0] == '.' && (name.len == 1 \|\|
	516	(vdir->d_name[1] == '.' && name.len == 2)))
	517	vdir->d_fileno = name.len = 0;
	518
	519	/* skip null entries */
	520	if (vdir->d_fileno && name.len) {
	521	/* try to look up this entry in the dcache, that way
	522	* userspace doesn't have to worry about breaking
	523	* getcwd by having mismatched inode numbers for
	524	* internal volume mountpoints. */
97875253	525	ino = find_inode_number(de, &name);
1da177e4 LT	526	if (!ino) ino = vdir->d_fileno;
	527
	528	type = CDT2DT(vdir->d_type);
97875253 JH	529	ret = filldir(buf, name.name, name.len,
97875253 JH	530	coda_file->f_pos, ino, type);
1da177e4 LT	531	/* failure means no space for filling in this round */
	532	if (ret < 0) break;
	533	result++;
	534	}
	535	/* we'll always have progress because d_reclen is unsigned and
	536	* we've already established it is non-zero. */
97875253 JH	537	coda_file->f_pos += vdir->d_reclen;
97875253 JH	538	}
5f47c7ea	539	out:
1da177e4 LT	540	kfree(vdir);
	541	return result ? result : ret;
	542	}
	543
	544	/* called when a cache lookup succeeds */
	545	static int coda_dentry_revalidate(struct dentry de, struct nameidata nd)
	546	{
34286d66	547	struct inode *inode;
1da177e4 LT	548	struct coda_inode_info *cii;
1da177e4 LT	549
34286d66 NP	550	if (nd->flags & LOOKUP_RCU)
	551	return -ECHILD;
	552
	553	inode = de->d_inode;
f7cc02b8	554	if (!inode \|\| coda_isroot(inode))
1da177e4 LT	555	goto out;
	556	if (is_bad_inode(inode))
	557	goto bad;
	558
	559	cii = ITOC(de->d_inode);
	560	if (!(cii->c_flags & (C_PURGE \| C_FLUSH)))
	561	goto out;
	562
	563	shrink_dcache_parent(de);
	564
	565	/* propagate for a flush */
	566	if (cii->c_flags & C_FLUSH)
	567	coda_flag_inode_children(inode, C_FLUSH);
	568
b7ab39f6	569	if (de->d_count > 1)
1da177e4 LT	570	/* pretend it's valid, but don't change the flags */
	571	goto out;
	572
	573	/* clear the flags. */
b5ce1d83	574	spin_lock(&cii->c_lock);
1da177e4	575	cii->c_flags &= ~(C_VATTR \| C_PURGE \| C_FLUSH);
b5ce1d83	576	spin_unlock(&cii->c_lock);
1da177e4	577	bad:
1da177e4 LT	578	return 0;
1da177e4 LT	579	out:
1da177e4 LT	580	return 1;
	581	}
	582
	583	/*
	584	* This is the callback from dput() when d_count is going to 0.
	585	* We use this to unhash dentries with bad inodes.
	586	*/
fe15ce44	587	static int coda_dentry_delete(const struct dentry * dentry)
1da177e4 LT	588	{
	589	int flags;
	590
	591	if (!dentry->d_inode)
	592	return 0;
	593
	594	flags = (ITOC(dentry->d_inode)->c_flags) & C_PURGE;
	595	if (is_bad_inode(dentry->d_inode) \|\| flags) {
	596	return 1;
	597	}
	598	return 0;
	599	}
	600
	601
	602
	603	/*
	604	* This is called when we want to check if the inode has
	605	* changed on the server. Coda makes this easy since the
	606	* cache manager Venus issues a downcall to the kernel when this
	607	* happens
	608	*/
	609	int coda_revalidate_inode(struct dentry *dentry)
	610	{
	611	struct coda_vattr attr;
f7cc02b8	612	int error;
1da177e4 LT	613	int old_mode;
	614	ino_t old_ino;
	615	struct inode *inode = dentry->d_inode;
	616	struct coda_inode_info *cii = ITOC(inode);
	617
f7cc02b8 YA	618	if (!cii->c_flags)
f7cc02b8 YA	619	return 0;
1da177e4 LT	620
	621	if (cii->c_flags & (C_VATTR \| C_PURGE \| C_FLUSH)) {
	622	error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
f7cc02b8 YA	623	if (error)
f7cc02b8 YA	624	return -EIO;
1da177e4 LT	625
	626	/* this inode may be lost if:
	627	- it's ino changed
	628	- type changes must be permitted for repair and
	629	missing mount points.
	630	*/
	631	old_mode = inode->i_mode;
	632	old_ino = inode->i_ino;
	633	coda_vattr_to_iattr(inode, &attr);
	634
	635	if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
	636	printk("Coda: inode %ld, fid %s changed type!\n",
	637	inode->i_ino, coda_f2s(&(cii->c_fid)));
	638	}
	639
	640	/* the following can happen when a local fid is replaced
	641	with a global one, here we lose and declare the inode bad */
	642	if (inode->i_ino != old_ino)
f7cc02b8	643	return -EIO;
1da177e4 LT	644
1da177e4 LT	645	coda_flag_inode_children(inode, C_FLUSH);
b5ce1d83 YA	646
b5ce1d83 YA	647	spin_lock(&cii->c_lock);
1da177e4	648	cii->c_flags &= ~(C_VATTR \| C_PURGE \| C_FLUSH);
b5ce1d83	649	spin_unlock(&cii->c_lock);
1da177e4	650	}
1da177e4	651	return 0;
1da177e4	652	}