patch-2.1.78 linux/fs/hfs/dir_dbl.c

• Lines: 464
• Date: Sun Jan 4 10:40:17 1998
• Orig file: v2.1.77/linux/fs/hfs/dir_dbl.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.77/linux/fs/hfs/dir_dbl.c linux/fs/hfs/dir_dbl.c
@@ -0,0 +1,463 @@
+/*
+ * linux/fs/hfs/dir_dbl.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * This file may be distributed under the terms of the GNU Public License.
+ *
+ * This file contains the inode_operations and file_operations
+ * structures for HFS directories.
+ *
+ * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
+ *
+ * "XXX" in a comment is a note to myself to consider changing something.
+ *
+ * In function preconditions the term "valid" applied to a pointer to
+ * a structure means that the pointer is non-NULL and the structure it
+ * points to has all fields initialized to consistent values.
+ */
+
+#include "hfs.h"
+#include <linux/hfs_fs_sb.h>
+#include <linux/hfs_fs_i.h>
+#include <linux/hfs_fs.h>
+
+/*================ Forward declarations ================*/
+
+static int dbl_lookup(struct inode *, struct dentry *);
+static int dbl_readdir(struct file *, void *, filldir_t);
+static int dbl_create(struct inode *, struct dentry *, int);
+static int dbl_mkdir(struct inode *, struct dentry *, int);
+static int dbl_mknod(struct inode *, struct dentry *, int, int);
+static int dbl_unlink(struct inode *, struct dentry *);
+static int dbl_rmdir(struct inode *, struct dentry *);
+static int dbl_rename(struct inode *, struct dentry *,
+		      struct inode *, struct dentry *);
+
+/*================ Global variables ================*/
+
+#define DOT_LEN			1
+#define DOT_DOT_LEN		2
+#define ROOTINFO_LEN		8
+#define PCNT_ROOTINFO_LEN	9
+
+const struct hfs_name hfs_dbl_reserved1[] = {
+	{DOT_LEN,		"."},
+	{DOT_DOT_LEN,		".."},
+	{0,			""},
+};
+
+const struct hfs_name hfs_dbl_reserved2[] = {
+	{ROOTINFO_LEN,		"RootInfo"},
+	{PCNT_ROOTINFO_LEN,	"%RootInfo"},
+	{0,			""},
+};
+
+#define DOT		(&hfs_dbl_reserved1[0])
+#define DOT_DOT		(&hfs_dbl_reserved1[1])
+#define ROOTINFO	(&hfs_dbl_reserved2[0])
+#define PCNT_ROOTINFO	(&hfs_dbl_reserved2[1])
+
+static struct file_operations hfs_dbl_dir_operations = {
+	NULL,			/* lseek - default */
+	hfs_dir_read,		/* read - invalid */
+	NULL,			/* write - bad */
+	dbl_readdir,		/* readdir */
+	NULL,			/* select - default */
+	NULL,			/* ioctl - default */
+	NULL,			/* mmap - none */
+	NULL,			/* no special open code */
+	NULL,			/* no special release code */
+	file_fsync,		/* fsync - default */
+        NULL,			/* fasync - default */
+        NULL,			/* check_media_change - none */
+        NULL			/* revalidate - none */
+};
+
+struct inode_operations hfs_dbl_dir_inode_operations = {
+	&hfs_dbl_dir_operations,/* default directory file-ops */
+	dbl_create,		/* create */
+	dbl_lookup,		/* lookup */
+	NULL,			/* link */
+	dbl_unlink,		/* unlink */
+	NULL,			/* symlink */
+	dbl_mkdir,		/* mkdir */
+	dbl_rmdir,		/* rmdir */
+	dbl_mknod,		/* mknod */
+	dbl_rename,		/* rename */
+	NULL,			/* readlink */
+	NULL,			/* follow_link */
+	NULL,			/* readpage */
+	NULL,			/* writepage */
+	NULL,			/* bmap */
+	NULL,			/* truncate */
+	NULL,			/* permission */
+	NULL			/* smap */
+};
+
+
+/*================ File-local functions ================*/
+
+/*
+ * is_hdr()
+ */
+static int is_hdr(struct inode *dir, const char *name, int len)
+{
+	int retval = 0;
+
+	if (name[0] == '%') {
+		struct hfs_cat_entry *entry = HFS_I(dir)->entry;
+		struct hfs_cat_entry *victim;
+		struct hfs_name cname;
+		struct hfs_cat_key key;
+
+		hfs_nameout(dir, &cname, name+1, len-1);
+		hfs_cat_build_key(entry->cnid, &cname, &key);
+		if ((victim = hfs_cat_get(entry->mdb, &key))) {
+			hfs_cat_put(victim);
+			retval = 1;
+		}
+	}
+	return retval;
+}
+
+/*
+ * dbl_lookup()
+ *
+ * This is the lookup() entry in the inode_operations structure for
+ * HFS directories in the AppleDouble scheme.  The purpose is to
+ * generate the inode corresponding to an entry in a directory, given
+ * the inode for the directory and the name (and its length) of the
+ * entry.
+ */
+static int dbl_lookup(struct inode * dir, struct dentry *dentry)
+{
+	struct hfs_name cname;
+	struct hfs_cat_entry *entry;
+	struct hfs_cat_key key;
+	struct inode *inode = NULL;
+	
+	if (!dir || !S_ISDIR(dir->i_mode)) {
+		goto done;
+	}
+
+	entry = HFS_I(dir)->entry;
+	
+	/* Perform name-mangling */
+	hfs_nameout(dir, &cname, dentry->d_name.name, dentry->d_name.len);
+ 
+	/* Check for "." */
+	if (hfs_streq(&cname, DOT)) {
+		/* this little trick skips the iget and iput */
+		d_add(dentry, dir);
+		return 0;
+	}
+
+	/* Check for "..". */
+	if (hfs_streq(&cname, DOT_DOT)) {
+		inode = hfs_iget(hfs_cat_parent(entry), HFS_DBL_DIR, dentry);
+		goto done;
+	}
+
+	/* Check for "%RootInfo" if in the root directory. */
+	if ((entry->cnid == htonl(HFS_ROOT_CNID)) &&
+	    hfs_streq(&cname, PCNT_ROOTINFO)) {
+		++entry->count; /* __hfs_iget() eats one */
+		inode = hfs_iget(entry, HFS_DBL_HDR, dentry);
+		goto done;
+	}
+
+	/* Do an hfs_iget() on the mangled name. */
+	hfs_cat_build_key(entry->cnid, &cname, &key);
+	inode = hfs_iget(hfs_cat_get(entry->mdb, &key), HFS_DBL_NORM, dentry);
+
+	/* Try as a header if not found and first character is '%' */
+	if (!inode && (dentry->d_name.name[0] == '%')) {
+		hfs_nameout(dir, &cname, dentry->d_name.name+1,
+			    dentry->d_name.len-1);
+		hfs_cat_build_key(entry->cnid, &cname, &key);
+		inode = hfs_iget(hfs_cat_get(entry->mdb, &key), 
+				 HFS_DBL_HDR, dentry);
+	}
+	
+done:
+	d_add(dentry, inode);
+	return 0;
+}
+
+/*
+ * dbl_readdir()
+ *
+ * This is the readdir() entry in the file_operations structure for
+ * HFS directories in the AppleDouble scheme.  The purpose is to
+ * enumerate the entries in a directory, given the inode of the
+ * directory and a (struct file *), the 'f_pos' field of which
+ * indicates the location in the directory.  The (struct file *) is
+ * updated so that the next call with the same 'dir' and 'filp'
+ * arguments will produce the next directory entry.  The entries are
+ * returned in 'dirent', which is "filled-in" by calling filldir().
+ * This allows the same readdir() function be used for different
+ * formats.  We try to read in as many entries as we can before
+ * filldir() refuses to take any more.
+ *
+ * XXX: In the future it may be a good idea to consider not generating
+ * metadata files for covered directories since the data doesn't
+ * correspond to the mounted directory.	 However this requires an
+ * iget() for every directory which could be considered an excessive
+ * amount of overhead.	Since the inode for a mount point is always
+ * in-core this is another argument for a call to get an inode if it
+ * is in-core or NULL if it is not.
+ */
+static int dbl_readdir(struct file * filp,
+		       void * dirent, filldir_t filldir)
+{
+	struct hfs_brec brec;
+        struct hfs_cat_entry *entry;
+	struct inode *dir = filp->f_dentry->d_inode;
+
+	if (!dir || !dir->i_sb || !S_ISDIR(dir->i_mode)) {
+		return -EBADF;
+	}
+
+        entry = HFS_I(dir)->entry;
+
+	if (filp->f_pos == 0) {
+		/* Entry 0 is for "." */
+		if (filldir(dirent, DOT->Name, DOT_LEN, 0, dir->i_ino)) {
+			return 0;
+		}
+		filp->f_pos = 1;
+	}
+
+	if (filp->f_pos == 1) {
+		/* Entry 1 is for ".." */
+		if (filldir(dirent, DOT_DOT->Name, DOT_DOT_LEN, 1,
+			    hfs_get_hl(entry->key.ParID))) {
+			return 0;
+		}
+		filp->f_pos = 2;
+	}
+
+	if (filp->f_pos < (dir->i_size - 1)) {
+                hfs_u32 cnid;
+                hfs_u8 type;
+
+		if (hfs_cat_open(entry, &brec) ||
+		    hfs_cat_next(entry, &brec, (filp->f_pos - 1) >> 1,
+				 &cnid, &type)) {
+			return 0;
+		}
+
+		while (filp->f_pos < (dir->i_size - 1)) {
+			unsigned char tmp_name[HFS_NAMEMAX + 1];
+			ino_t ino;
+			int is_hdr = (filp->f_pos & 1);
+			unsigned int len;
+
+			if (is_hdr) {
+				ino = ntohl(cnid) | HFS_DBL_HDR;
+				tmp_name[0] = '%';
+				len = 1 + hfs_namein(dir, tmp_name + 1,
+				    &((struct hfs_cat_key *)brec.key)->CName);
+			} else {
+				if (hfs_cat_next(entry, &brec, 1,
+							&cnid, &type)) {
+					return 0;
+				}
+				ino = ntohl(cnid);
+				len = hfs_namein(dir, tmp_name,
+				    &((struct hfs_cat_key *)brec.key)->CName);
+			}
+
+			if (filldir(dirent, tmp_name, len, filp->f_pos, ino)) {
+				hfs_cat_close(entry, &brec);
+				return 0;
+			}
+			++filp->f_pos;
+		}
+		hfs_cat_close(entry, &brec);
+	}
+
+	if (filp->f_pos == (dir->i_size - 1)) {
+		if (entry->cnid == htonl(HFS_ROOT_CNID)) {
+			/* In root dir last entry is for "%RootInfo" */
+			if (filldir(dirent, PCNT_ROOTINFO->Name,
+				    PCNT_ROOTINFO_LEN, filp->f_pos,
+				    ntohl(entry->cnid) | HFS_DBL_HDR)) {
+				return 0;
+			}
+		}
+		++filp->f_pos;
+	}
+
+	return 0;
+}
+
+/*
+ * dbl_create()
+ *
+ * This is the create() entry in the inode_operations structure for
+ * AppleDouble directories.  The purpose is to create a new file in
+ * a directory and return a corresponding inode, given the inode for
+ * the directory and the name (and its length) of the new file.
+ */
+static int dbl_create(struct inode * dir, struct dentry *dentry,
+		      int mode)
+{
+	int error;
+
+	if (is_hdr(dir, dentry->d_name.name, dentry->d_name.len)) {
+		error = -EEXIST;
+	} else {
+		error = hfs_create(dir, dentry, mode);
+	}
+	return error;
+}
+
+/*
+ * dbl_mkdir()
+ *
+ * This is the mkdir() entry in the inode_operations structure for
+ * AppleDouble directories.  The purpose is to create a new directory
+ * in a directory, given the inode for the parent directory and the
+ * name (and its length) of the new directory.
+ */
+static int dbl_mkdir(struct inode * parent, struct dentry *dentry,
+		     int mode)
+{
+	int error;
+
+	if (is_hdr(parent, dentry->d_name.name, dentry->d_name.len)) {
+		error = -EEXIST;
+	} else {
+		error = hfs_mkdir(parent, dentry, mode);
+	}
+	return error;
+}
+
+/*
+ * dbl_mknod()
+ *
+ * This is the mknod() entry in the inode_operations structure for
+ * regular HFS directories.  The purpose is to create a new entry
+ * in a directory, given the inode for the parent directory and the
+ * name (and its length) and the mode of the new entry (and the device
+ * number if the entry is to be a device special file).
+ */
+static int dbl_mknod(struct inode *dir, struct dentry *dentry,
+		     int mode, int rdev)
+{
+	int error;
+
+	if (is_hdr(dir, dentry->d_name.name, dentry->d_name.len)) {
+		error = -EEXIST;
+	} else {
+		error = hfs_mknod(dir, dentry, mode, rdev);
+	}
+	return error;
+}
+
+/*
+ * dbl_unlink()
+ *
+ * This is the unlink() entry in the inode_operations structure for
+ * AppleDouble directories.  The purpose is to delete an existing
+ * file, given the inode for the parent directory and the name
+ * (and its length) of the existing file.
+ */
+static int dbl_unlink(struct inode * dir, struct dentry *dentry)
+{
+	int error;
+
+	error = hfs_unlink(dir, dentry);
+	if ((error == -ENOENT) && is_hdr(dir, dentry->d_name.name,
+					 dentry->d_name.len)) {
+		error = -EPERM;
+	}
+	return error;
+}
+
+/*
+ * dbl_rmdir()
+ *
+ * This is the rmdir() entry in the inode_operations structure for
+ * AppleDouble directories.  The purpose is to delete an existing
+ * directory, given the inode for the parent directory and the name
+ * (and its length) of the existing directory.
+ */
+static int dbl_rmdir(struct inode * parent, struct dentry *dentry)
+{
+	int error;
+
+	error = hfs_rmdir(parent, dentry);
+	if ((error == -ENOENT) && is_hdr(parent, dentry->d_name.name,
+					 dentry->d_name.len)) {
+		error = -ENOTDIR;
+	}
+	return error;
+}
+
+/*
+ * dbl_rename()
+ *
+ * This is the rename() entry in the inode_operations structure for
+ * AppleDouble directories.  The purpose is to rename an existing
+ * file or directory, given the inode for the current directory and
+ * the name (and its length) of the existing file/directory and the
+ * inode for the new directory and the name (and its length) of the
+ * new file/directory.
+ * 
+ * XXX: how do we handle must_be_dir?
+ */
+static int dbl_rename(struct inode *old_dir, struct dentry *old_dentry,
+		      struct inode *new_dir, struct dentry *new_dentry)
+{
+	int error;
+
+	if (is_hdr(new_dir, new_dentry->d_name.name, 
+		   new_dentry->d_name.len)) {
+		error = -EPERM;
+	} else {
+		error = hfs_rename(old_dir, old_dentry,
+				   new_dir, new_dentry);
+		if ((error == -ENOENT) /*&& !must_be_dir*/ &&
+		    is_hdr(old_dir, old_dentry->d_name.name, 
+			   old_dentry->d_name.len)) {
+			error = -EPERM;
+		}
+	}
+	return error;
+}
+
+
+/* due to the dcache caching negative dentries for non-existent files,
+ * we need to drop those entries when a file silently gets created.
+ * as far as i can tell, the calls that need to do this are the file
+ * related calls (create, rename, and mknod). the directory calls
+ * should be immune. the relevant calls in dir.c call drop_dentry 
+ * upon successful completion. this allocates an array for %name
+ * on the first attempt to access it. */
+void hfs_dbl_drop_dentry(const ino_t type, struct dentry *dentry)
+{
+  unsigned char tmp_name[HFS_NAMEMAX + 1];
+  struct dentry *de = NULL;
+
+  switch (type) {
+  case HFS_DBL_HDR:
+   /* given %name, look for name. i don't think this happens. */
+   de = hfs_lookup_dentry(dentry->d_name.name + 1, dentry->d_name.len - 1,
+			   dentry->d_parent);
+    break;
+  case HFS_DBL_DATA:
+    /* given name, look for %name */
+    tmp_name[0] = '%';
+    strncpy(tmp_name + 1, dentry->d_name.name, HFS_NAMELEN - 1);
+    de = hfs_lookup_dentry(tmp_name, dentry->d_name.len + 1,
+			     dentry->d_parent);
+  }
+
+  if (de) {
+    if (!de->d_inode)
+      d_drop(de);
+    dput(de);
+  }
+}