[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 ([email protected]).
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/fs.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 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, struct nameidata *nd)
{
        int error = 0;
 
	if (!mask)
		return 0; 

	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 */
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;
}

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