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

• Lines: 403
• Date: Sun Jan 4 10:40:17 1998
• Orig file: v2.1.77/linux/fs/hfs/dir_cap.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.77/linux/fs/hfs/dir_cap.c linux/fs/hfs/dir_cap.c
@@ -0,0 +1,402 @@
+/*
+ * linux/fs/hfs/dir_cap.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 under the CAP scheme.
+ *
+ * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
+ *
+ * The source code distribution of the Columbia AppleTalk Package for
+ * UNIX, version 6.0, (CAP) was used as a specification of the
+ * location and format of files used by CAP's Aufs.  No code from CAP
+ * appears in hfs_fs.  hfs_fs is not a work ``derived'' from CAP in
+ * the sense of intellectual property law.
+ *
+ * "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 cap_lookup(struct inode *, struct dentry *);
+static int cap_readdir(struct file *, void *, filldir_t);
+
+/*================ Global variables ================*/
+
+#define DOT_LEN			1
+#define DOT_DOT_LEN		2
+#define DOT_RESOURCE_LEN	9
+#define DOT_FINDERINFO_LEN	11
+#define DOT_ROOTINFO_LEN	9
+
+const struct hfs_name hfs_cap_reserved1[] = {
+	{DOT_LEN,		"."},
+	{DOT_DOT_LEN,		".."},
+	{DOT_RESOURCE_LEN,	".resource"},
+	{DOT_FINDERINFO_LEN,	".finderinfo"},
+	{0,			""},
+};
+
+const struct hfs_name hfs_cap_reserved2[] = {
+	{DOT_ROOTINFO_LEN,	".rootinfo"},
+	{0,			""},
+};
+
+#define DOT		(&hfs_cap_reserved1[0])
+#define DOT_DOT		(&hfs_cap_reserved1[1])
+#define DOT_RESOURCE	(&hfs_cap_reserved1[2])
+#define DOT_FINDERINFO	(&hfs_cap_reserved1[3])
+#define DOT_ROOTINFO	(&hfs_cap_reserved2[0])
+
+static struct file_operations hfs_cap_dir_operations = {
+	NULL,			/* lseek - default */
+	hfs_dir_read,		/* read - invalid */
+	NULL,			/* write - bad */
+	cap_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_cap_ndir_inode_operations = {
+	&hfs_cap_dir_operations,/* default directory file-ops */
+	hfs_create,		/* create */
+	cap_lookup,		/* lookup */
+	NULL,			/* link */
+	hfs_unlink,		/* unlink */
+	NULL,			/* symlink */
+	hfs_mkdir,		/* mkdir */
+	hfs_rmdir,		/* rmdir */
+	hfs_mknod,		/* mknod */
+	hfs_rename,		/* rename */
+	NULL,			/* readlink */
+	NULL,			/* follow_link */
+	NULL,			/* readpage */
+	NULL,			/* writepage */
+	NULL,			/* bmap */
+	NULL,			/* truncate */
+	NULL,			/* permission */
+	NULL			/* smap */
+};
+
+struct inode_operations hfs_cap_fdir_inode_operations = {
+	&hfs_cap_dir_operations,/* default directory file-ops */
+	NULL,			/* create */
+	cap_lookup,		/* lookup */
+	NULL,			/* link */
+	NULL,			/* unlink */
+	NULL,			/* symlink */
+	NULL,			/* mkdir */
+	NULL,			/* rmdir */
+	NULL,			/* mknod */
+	NULL,			/* rename */
+	NULL,			/* readlink */
+	NULL,			/* follow_link */
+	NULL,			/* readpage */
+	NULL,			/* writepage */
+	NULL,			/* bmap */
+	NULL,			/* truncate */
+	NULL,			/* permission */
+	NULL			/* smap */
+};
+
+struct inode_operations hfs_cap_rdir_inode_operations = {
+	&hfs_cap_dir_operations,/* default directory file-ops */
+	hfs_create,		/* create */
+	cap_lookup,		/* lookup */
+	NULL,			/* link */
+	NULL,			/* unlink */
+	NULL,			/* symlink */
+	NULL,			/* mkdir */
+	NULL,			/* rmdir */
+	NULL,			/* mknod */
+	NULL,			/* rename */
+	NULL,			/* readlink */
+	NULL,			/* follow_link */
+	NULL,			/* readpage */
+	NULL,			/* writepage */
+	NULL,			/* bmap */
+	NULL,			/* truncate */
+	NULL,			/* permission */
+	NULL			/* smap */
+};
+
+/*================ File-local functions ================*/
+
+/*
+ * cap_lookup()
+ *
+ * This is the lookup() entry in the inode_operations structure for
+ * HFS directories in the CAP 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 cap_lookup(struct inode * dir, struct dentry *dentry)
+{
+	ino_t dtype;
+	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;
+	dtype = HFS_ITYPE(dir->i_ino);
+
+	/* 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)) {
+		struct hfs_cat_entry *parent;
+
+		if (dtype != HFS_CAP_NDIR) {
+			/* Case for ".." in ".finderinfo" or ".resource" */
+			parent = entry;
+			++entry->count; /* __hfs_iget() eats one */
+		} else {
+			/* Case for ".." in a normal directory */
+			parent = hfs_cat_parent(entry);
+		}
+		inode = hfs_iget(parent, HFS_CAP_NDIR, dentry);
+		goto done;
+	}
+
+	/* Check for special directories if in a normal directory.
+	   Note that cap_dupdir() does an iput(dir). */
+	if (dtype==HFS_CAP_NDIR) {
+		/* Check for ".resource", ".finderinfo" and ".rootinfo" */
+		if (hfs_streq(&cname, DOT_RESOURCE)) {
+			++entry->count; /* __hfs_iget() eats one */
+			inode = hfs_iget(entry, HFS_CAP_RDIR, dentry);
+			goto done;
+		} else if (hfs_streq(&cname, DOT_FINDERINFO)) {
+			++entry->count; /* __hfs_iget() eats one */
+			inode = hfs_iget(entry, HFS_CAP_FDIR, dentry);
+			goto done;
+		} else if ((entry->cnid == htonl(HFS_ROOT_CNID)) &&
+			   hfs_streq(&cname, DOT_ROOTINFO)) {
+			++entry->count; /* __hfs_iget() eats one */
+			inode = hfs_iget(entry, HFS_CAP_FNDR, 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_I(dir)->file_type, dentry);
+
+	/* Don't return a resource fork for a directory */
+	if (inode && (dtype == HFS_CAP_RDIR) &&
+	    (HFS_I(inode)->entry->type == HFS_CDR_DIR)) {
+		inode = NULL;
+	}
+
+done:
+	d_add(dentry, inode);
+	return 0;
+}
+
+/*
+ * cap_readdir()
+ *
+ * This is the readdir() entry in the file_operations structure for
+ * HFS directories in the CAP 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 dirent 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 cap_readdir(struct file * filp,
+		       void * dirent, filldir_t filldir)
+{
+	ino_t type;
+	int skip_dirs;
+	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;
+	type = HFS_ITYPE(dir->i_ino);
+	skip_dirs = (type == HFS_CAP_RDIR);
+
+	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 ".." */
+		hfs_u32 cnid;
+
+		if (type == HFS_CAP_NDIR) {
+			cnid = hfs_get_nl(entry->key.ParID);
+		} else {
+			cnid = entry->cnid;
+		}
+
+		if (filldir(dirent, DOT_DOT->Name,
+			    DOT_DOT_LEN, 1, ntohl(cnid))) {
+			return 0;
+		}
+		filp->f_pos = 2;
+	}
+
+	if (filp->f_pos < (dir->i_size - 3)) {
+		hfs_u32 cnid;
+		hfs_u8 type;
+
+	    	if (hfs_cat_open(entry, &brec) ||
+	    	    hfs_cat_next(entry, &brec, filp->f_pos - 2, &cnid, &type)) {
+			return 0;
+		}
+		while (filp->f_pos < (dir->i_size - 3)) {
+			if (hfs_cat_next(entry, &brec, 1, &cnid, &type)) {
+				return 0;
+			}
+			if (!skip_dirs || (type != HFS_CDR_DIR)) {
+				ino_t ino;
+				unsigned int len;
+				unsigned char tmp_name[HFS_NAMEMAX];
+
+				ino = ntohl(cnid) | HFS_I(dir)->file_type;
+				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 - 3)) {
+		if ((entry->cnid == htonl(HFS_ROOT_CNID)) &&
+		    (type == HFS_CAP_NDIR)) {
+			/* In root dir last-2 entry is for ".rootinfo" */
+			if (filldir(dirent, DOT_ROOTINFO->Name,
+				    DOT_ROOTINFO_LEN, filp->f_pos,
+				    ntohl(entry->cnid) | HFS_CAP_FNDR)) {
+				return 0;
+			}
+		}
+		++filp->f_pos;
+	}
+
+	if (filp->f_pos == (dir->i_size - 2)) {
+		if (type == HFS_CAP_NDIR) {
+			/* In normal dirs last-1 entry is for ".finderinfo" */
+			if (filldir(dirent, DOT_FINDERINFO->Name,
+				    DOT_FINDERINFO_LEN, filp->f_pos,
+				    ntohl(entry->cnid) | HFS_CAP_FDIR)) {
+				return 0;
+			}
+		}
+		++filp->f_pos;
+	}
+
+	if (filp->f_pos == (dir->i_size - 1)) {
+		if (type == HFS_CAP_NDIR) {
+			/* In normal dirs last entry is for ".resource" */
+			if (filldir(dirent, DOT_RESOURCE->Name,
+				    DOT_RESOURCE_LEN, filp->f_pos,
+				    ntohl(entry->cnid) | HFS_CAP_RDIR)) {
+				return 0;
+			}
+		}
+		++filp->f_pos;
+	}
+
+	return 0;
+}
+
+
+/* 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. */
+void hfs_cap_drop_dentry(const ino_t type, struct dentry *dentry)
+{
+  if (type == HFS_CAP_DATA) { /* given name */
+    hfs_drop_special(DOT_FINDERINFO, dentry->d_parent, dentry);
+    hfs_drop_special(DOT_RESOURCE, dentry->d_parent, dentry);
+  } else {
+    struct dentry *de;
+
+    /* look for name */
+    if ((de = hfs_lookup_dentry(dentry->d_name.name,
+			       dentry->d_name.len,
+			       dentry->d_parent->d_parent))) {
+      if (!de->d_inode)
+	d_drop(de);
+      dput(de);
+    }
+    
+    switch (type) {
+    case HFS_CAP_RSRC: /* given .resource/name */
+       /* look for .finderinfo/name */
+      hfs_drop_special(DOT_FINDERINFO, dentry->d_parent->d_parent,
+		       dentry);
+      break;
+    case HFS_CAP_FNDR: /* given .finderinfo/name. i don't this 
+			* happens. */
+      /* look for .resource/name */
+      hfs_drop_special(DOT_RESOURCE, dentry->d_parent->d_parent,
+		       dentry);
+      break;
+    }
+  }
+}