dirty fix to merging

1 files changed, 646 insertions, 0 deletions

diff --git a/fs/coda/dir.c b/fs/coda/dir.c
new file mode 100644
index 00000000..17751582
--- /dev/null
+++ b/fs/coda/dir.c
@@ -0,0 +1,646 @@
+
+/*
+ * 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, umode_t 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, umode_t 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 super_block *sb = dir->i_sb;
+	const char *name = entry->d_name.name;
+	size_t length = entry->d_name.len;
+	struct inode *inode;
+	int type = 0;
+
+	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)) {
+		inode = coda_cnode_makectl(sb);
+		type = CODA_NOCACHE;
+	} else {
+		struct CodaFid fid = { { 0, } };
+		int error = venus_lookup(sb, coda_i2f(dir), name, length,
+				     &type, &fid);
+		inode = !error ? coda_cnode_make(&fid, sb) : ERR_PTR(error);
+	}
+
+	if (!IS_ERR(inode) && (type & CODA_NOCACHE))
+		coda_flag_inode(inode, C_VATTR | C_PURGE);
+
+	if (inode == ERR_PTR(-ENOENT))
+		inode = NULL;
+
+	return d_splice_alias(inode, entry);
+}
+
+
+int coda_permission(struct inode *inode, int mask)
+{
+	int error;
+
+	if (mask & MAY_NOT_BLOCK)
+		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, umode_t 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, umode_t 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;
+
+	error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
+	if (!error) {
+		/* VFS may delete the child */
+		if (de->d_inode)
+			clear_nlink(de->d_inode);
+
+		/* 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 = offsetof(struct venus_dirent, 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, parent_ino(de), 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;
+}