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

• Lines: 424
• Date: Sun Jan 4 10:40:17 1998
• Orig file: v2.1.77/linux/fs/hfs/inode.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.77/linux/fs/hfs/inode.c linux/fs/hfs/inode.c
@@ -0,0 +1,423 @@
+/*
+ * linux/fs/hfs/inode.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * This file may be distributed under the terms of the GNU Public License.
+ *
+ * This file contains inode-related functions which do not depend on
+ * which scheme is being used to represent forks.
+ *
+ * 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>
+
+/*================ Variable-like macros ================*/
+
+#define HFS_VALID_MODE_BITS  (S_IFREG | S_IFDIR | S_IRWXUGO)
+
+/*================ File-local functions ================*/
+
+/*
+ * init_file_inode()
+ *
+ * Given an HFS catalog entry initialize an inode for a file.
+ */
+static void init_file_inode(struct inode *inode, hfs_u8 fork)
+{
+	struct hfs_fork *fk;
+	struct hfs_cat_entry *entry = HFS_I(inode)->entry;
+
+	if (!IS_NOEXEC(inode) && (fork == HFS_FK_DATA)) {
+		inode->i_mode = S_IRWXUGO | S_IFREG;
+	} else {
+		inode->i_mode = S_IRUGO | S_IWUGO | S_IFREG;
+	}
+
+	if (fork == HFS_FK_DATA) {
+		hfs_u32 type = hfs_get_nl(entry->info.file.finfo.fdType);
+
+		fk = &entry->u.file.data_fork;
+		HFS_I(inode)->convert =
+			((HFS_SB(inode->i_sb)->s_conv == 't') ||
+			 ((HFS_SB(inode->i_sb)->s_conv == 'a') &&
+			  ((type == htonl(0x54455854)) ||   /* "TEXT" */
+			   (type == htonl(0x7474726f)))));  /* "ttro" */
+	} else {
+		fk = &entry->u.file.rsrc_fork;
+		HFS_I(inode)->convert = 0;
+	}
+	HFS_I(inode)->fork = fk;
+	inode->i_size = fk->lsize;
+	inode->i_blocks = fk->psize;
+	inode->i_nlink = 1;
+}
+
+/*================ Global functions ================*/
+
+/*
+ * hfs_put_inode()
+ *
+ * This is the put_inode() entry in the super_operations for HFS
+ * filesystems.  The purpose is to perform any filesystem-dependent 
+ * cleanup necessary when the use-count of an inode falls to zero.
+ */
+void hfs_put_inode(struct inode * inode)
+{
+	struct hfs_cat_entry *entry = HFS_I(inode)->entry;
+
+	entry->sys_entry[HFS_ITYPE_TO_INT(HFS_ITYPE(inode->i_ino))] = NULL;
+	hfs_cat_put(entry);
+
+	if (inode->i_count == 1) {
+		struct hfs_hdr_layout *tmp = HFS_I(inode)->layout;
+		if (tmp) {
+			HFS_I(inode)->layout = NULL;
+			HFS_DELETE(tmp);
+		}
+	}
+}
+
+/*
+ * hfs_notify_change()
+ *
+ * Based very closely on fs/msdos/inode.c by Werner Almesberger
+ *
+ * This is the notify_change() field in the super_operations structure
+ * for HFS file systems.  The purpose is to take that changes made to
+ * an inode and apply then in a filesystem-dependent manner.  In this
+ * case the process has a few of tasks to do:
+ *  1) prevent changes to the i_uid and i_gid fields.
+ *  2) map file permissions to the closest allowable permissions
+ *  3) Since multiple Linux files can share the same on-disk inode under
+ *     HFS (for instance the data and resource forks of a file) a change
+ *     to permissions must be applied to all other in-core inodes which 
+ *     correspond to the same HFS file.
+ */
+int hfs_notify_change(struct inode * inode, struct iattr * attr)
+{
+	struct hfs_cat_entry *entry = HFS_I(inode)->entry;
+	struct dentry **de = entry->sys_entry;
+	struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
+	int error, i;
+
+	error = inode_change_ok(inode, attr); /* basic permission checks */
+	if (error) {
+		/* Let netatalk's afpd think chmod() always succeeds */
+		if (hsb->s_afpd &&
+		    (attr->ia_valid == (ATTR_MODE | ATTR_CTIME))) {
+			return 0;
+		} else {
+			return error;
+		}
+	}
+
+	/* no uig/gid changes and limit which mode bits can be set */
+	if (((attr->ia_valid & ATTR_UID) && 
+	     (attr->ia_uid != hsb->s_uid)) ||
+	    ((attr->ia_valid & ATTR_GID) && 
+	     (attr->ia_gid != hsb->s_gid)) ||
+	    ((attr->ia_valid & ATTR_MODE) &&
+	     (((entry->type == HFS_CDR_DIR) &&
+	       (attr->ia_mode != inode->i_mode))||
+	      (attr->ia_mode & ~HFS_VALID_MODE_BITS)))) {
+		return hsb->s_quiet ? 0 : error;
+	}
+	
+	if (entry->type == HFS_CDR_DIR) {
+		attr->ia_valid &= ~ATTR_MODE;
+	} else if (attr->ia_valid & ATTR_MODE) {
+		/* Only the 'w' bits can ever change and only all together. */
+		if (attr->ia_mode & S_IWUSR) {
+			attr->ia_mode = inode->i_mode | S_IWUGO;
+		} else {
+			attr->ia_mode = inode->i_mode & ~S_IWUGO;
+		}
+		attr->ia_mode &= ~hsb->s_umask;
+	}
+	inode_setattr(inode, attr);
+
+	/* We wouldn't want to mess with the sizes of the other fork */
+	attr->ia_valid &= ~ATTR_SIZE;
+
+	/* We must change all in-core inodes corresponding to this file. */
+	for (i = 0; i < 4; ++i) {
+	  if (de[i] && (de[i]->d_inode != inode)) {
+			inode_setattr(de[i]->d_inode, attr);
+	  }
+	}
+
+	/* Change the catalog entry if needed */
+	if (attr->ia_valid & ATTR_MTIME) {
+		entry->modify_date = hfs_u_to_mtime(inode->i_mtime);
+		entry->dirt = 1;
+	}
+	if (attr->ia_valid & ATTR_MODE) {
+		hfs_u8 new_flags;
+
+		if (inode->i_mode & S_IWUSR) {
+			new_flags = entry->u.file.flags & ~HFS_FIL_LOCK;
+		} else {
+			new_flags = entry->u.file.flags | HFS_FIL_LOCK;
+		}
+
+		if (new_flags != entry->u.file.flags) {
+			entry->u.file.flags = new_flags;
+			entry->dirt = 1;
+		}
+	}
+	/* size changes handled in hfs_extent_adj() */
+
+	return 0;
+}
+
+/*
+ * __hfs_iget()
+ *
+ * Given the MDB for a HFS filesystem, a 'key' and an 'entry' in
+ * the catalog B-tree and the 'type' of the desired file return the
+ * inode for that file/directory or NULL.  Note that 'type' indicates
+ * whether we want the actual file or directory, or the corresponding
+ * metadata (AppleDouble header file or CAP metadata file).
+ *
+ * In an ideal world we could call iget() and would not need this
+ * function.  However, since there is no way to even know the inode
+ * number until we've found the file/directory in the catalog B-tree
+ * that simply won't happen.
+ *
+ * The main idea here is to look in the catalog B-tree to get the
+ * vital info about the file or directory (including the file id which
+ * becomes the inode number) and then to call iget() and return the
+ * inode if it is complete.  If it is not then we use the catalog
+ * entry to fill in the missing info, by calling the appropriate
+ * 'fillin' function.  Note that these fillin functions are
+ * essentially hfs_*_read_inode() functions, but since there is no way
+ * to pass the catalog entry through iget() to such a read_inode()
+ * function, we have to call them after iget() returns an incomplete
+ * inode to us.	 This is pretty much the same problem faced in the NFS
+ * code, and pretty much the same solution. The SMB filesystem deals
+ * with this in a different way: by using the address of the
+ * kmalloc()'d space which holds the data as the inode number.
+ *
+ * XXX: Both this function and NFS's corresponding nfs_fhget() would
+ * benefit from a way to pass an additional (void *) through iget() to
+ * the VFS read_inode() function.
+ */
+struct inode *hfs_iget(struct hfs_cat_entry *entry, ino_t type,
+		       struct dentry *dentry)
+{
+	struct dentry **sys_entry;
+	struct super_block *sb;
+	struct inode *inode;
+
+	if (!entry) {
+		return NULL;
+	}
+
+	/* If there are several processes all calling __iget() for
+	   the same inode then they will all get the same one back.
+	   The first one to return from __iget() will notice that the
+	   i_mode field of the inode is blank and KNOW that it is
+	   the first to return.  Therefore, it will set the appropriate
+	   'sys_entry' field in the entry and initialize the inode.
+	   All the initialization must be done without sleeping,
+	   or else other processes could end up using a partially
+	   initialized inode.				*/
+
+	sb = entry->mdb->sys_mdb;
+	sys_entry = &entry->sys_entry[HFS_ITYPE_TO_INT(type)];
+
+	if (*sys_entry && (inode = (*sys_entry)->d_inode)) {
+		/* There is an existing inode for this file/dir.  Use it. */
+		++inode->i_count;
+		hfs_cat_put(entry);
+	} else if (!(inode = iget(sb, ntohl(entry->cnid) | type)) ||
+		   (inode->i_dev != sb->s_dev)) {
+		/* Something went wrong */
+		hfs_cat_put(entry);
+	} else if (inode->i_mode) {
+		/* The inode has been initialized by another process.
+		   Note that if hfs_put_inode() is sleeping in hfs_cat_put()
+		   then we still need to attach it to the entry. */
+		if (*sys_entry) {
+			hfs_cat_put(entry);
+		} else {
+			*sys_entry = dentry; /* cache dentry */
+		}
+	} else {
+		/* Initialize the inode */
+		struct hfs_sb_info *hsb = HFS_SB(sb);
+
+		inode->i_rdev = 0;
+		inode->i_ctime = inode->i_atime = inode->i_mtime =
+					hfs_m_to_utime(entry->modify_date);
+		inode->i_blksize = HFS_SECTOR_SIZE;
+		inode->i_uid = hsb->s_uid;
+		inode->i_gid = hsb->s_gid;
+
+		memset(HFS_I(inode), 0, sizeof(struct hfs_inode_info));
+		HFS_I(inode)->magic = HFS_INO_MAGIC;
+		HFS_I(inode)->entry = entry;
+
+		hsb->s_ifill(inode, type);
+		if (!hsb->s_afpd && (entry->type == HFS_CDR_FIL) &&
+		    (entry->u.file.flags & HFS_FIL_LOCK)) {
+			inode->i_mode &= ~S_IWUGO;
+		}
+		inode->i_mode &= ~hsb->s_umask;
+
+		if (!inode->i_mode) {
+			clear_inode(inode);
+			inode = NULL;
+		} 
+
+		*sys_entry = dentry; /* cache dentry */
+	}
+
+	return inode;
+}
+
+/*================ Scheme-specific functions ================*/
+
+/* 
+ * hfs_cap_ifill()
+ *
+ * This function serves the same purpose as a read_inode() function does
+ * in other filesystems.  It is called by __hfs_iget() to fill in
+ * the missing fields of an uninitialized inode under the CAP scheme.
+ */
+void hfs_cap_ifill(struct inode * inode, ino_t type)
+{
+	struct hfs_cat_entry *entry = HFS_I(inode)->entry;
+
+	HFS_I(inode)->d_drop_op = hfs_cap_drop_dentry;
+	if (type == HFS_CAP_FNDR) {
+		inode->i_size = sizeof(struct hfs_cap_info);
+		inode->i_blocks = 0;
+		inode->i_nlink = 1;
+		inode->i_mode = S_IRUGO | S_IWUGO | S_IFREG;
+		inode->i_op = &hfs_cap_info_inode_operations;
+	} else if (entry->type == HFS_CDR_FIL) {
+		init_file_inode(inode, (type == HFS_CAP_DATA) ?
+						HFS_FK_DATA : HFS_FK_RSRC);
+		inode->i_op = &hfs_file_inode_operations;
+	} else { /* Directory */
+		struct hfs_dir *hdir = &entry->u.dir;
+
+		inode->i_blocks = 0;
+		inode->i_size = hdir->files + hdir->dirs + 5;
+		HFS_I(inode)->dir_size = 1;
+		if (type == HFS_CAP_NDIR) {
+			inode->i_mode = S_IRWXUGO | S_IFDIR;
+			inode->i_nlink = hdir->dirs + 4;
+			inode->i_op = &hfs_cap_ndir_inode_operations;
+			HFS_I(inode)->file_type = HFS_CAP_NORM;
+		} else if (type == HFS_CAP_FDIR) {
+			inode->i_mode = S_IRUGO | S_IXUGO | S_IFDIR;
+			inode->i_nlink = 2;
+			inode->i_op = &hfs_cap_fdir_inode_operations;
+			HFS_I(inode)->file_type = HFS_CAP_FNDR;
+		} else if (type == HFS_CAP_RDIR) {
+			inode->i_mode = S_IRUGO | S_IXUGO | S_IFDIR;
+			inode->i_nlink = 2;
+			inode->i_op = &hfs_cap_rdir_inode_operations;
+			HFS_I(inode)->file_type = HFS_CAP_RSRC;
+		}
+	}
+}
+
+/* 
+ * hfs_dbl_ifill()
+ *
+ * This function serves the same purpose as a read_inode() function does
+ * in other filesystems.  It is called by __hfs_iget() to fill in
+ * the missing fields of an uninitialized inode under the AppleDouble
+ * scheme.
+ */
+void hfs_dbl_ifill(struct inode * inode, ino_t type)
+{
+	struct hfs_cat_entry *entry = HFS_I(inode)->entry;
+
+	HFS_I(inode)->d_drop_op = hfs_dbl_drop_dentry;
+	if (type == HFS_DBL_HDR) {
+		if (entry->type == HFS_CDR_FIL) {
+			init_file_inode(inode, HFS_FK_RSRC);
+			inode->i_size += HFS_DBL_HDR_LEN;
+			HFS_I(inode)->default_layout = &hfs_dbl_fil_hdr_layout;
+		} else {
+			inode->i_size = HFS_DBL_HDR_LEN;
+			inode->i_mode = S_IRUGO | S_IWUGO | S_IFREG;
+			inode->i_nlink = 1;
+			HFS_I(inode)->default_layout = &hfs_dbl_dir_hdr_layout;
+		}
+		inode->i_op = &hfs_hdr_inode_operations;
+	} else if (entry->type == HFS_CDR_FIL) {
+		init_file_inode(inode, HFS_FK_DATA);
+		inode->i_op = &hfs_file_inode_operations;
+	} else { /* Directory */
+		struct hfs_dir *hdir = &entry->u.dir;
+
+		inode->i_blocks = 0;
+		inode->i_nlink = hdir->dirs + 2;
+		inode->i_size = 3 + 2 * (hdir->dirs + hdir->files);
+		inode->i_mode = S_IRWXUGO | S_IFDIR;
+		inode->i_op = &hfs_dbl_dir_inode_operations;
+		HFS_I(inode)->file_type = HFS_DBL_NORM;
+		HFS_I(inode)->dir_size = 2;
+	}
+}
+
+/* 
+ * hfs_nat_ifill()
+ *
+ * This function serves the same purpose as a read_inode() function does
+ * in other filesystems.  It is called by __hfs_iget() to fill in
+ * the missing fields of an uninitialized inode under the Netatalk
+ * scheme.
+ */
+void hfs_nat_ifill(struct inode * inode, ino_t type)
+{
+	struct hfs_cat_entry *entry = HFS_I(inode)->entry;
+
+	HFS_I(inode)->d_drop_op = hfs_nat_drop_dentry;
+	if (type == HFS_NAT_HDR) {
+		if (entry->type == HFS_CDR_FIL) {
+			init_file_inode(inode, HFS_FK_RSRC);
+			inode->i_size += HFS_NAT_HDR_LEN;
+		} else {
+			inode->i_size = HFS_NAT_HDR_LEN;
+			inode->i_mode = S_IRUGO | S_IWUGO | S_IFREG;
+			inode->i_nlink = 1;
+		}
+		inode->i_op = &hfs_hdr_inode_operations;
+		HFS_I(inode)->default_layout = &hfs_nat_hdr_layout;
+	} else if (entry->type == HFS_CDR_FIL) {
+		init_file_inode(inode, HFS_FK_DATA);
+		inode->i_op = &hfs_file_inode_operations;
+	} else { /* Directory */
+		struct hfs_dir *hdir = &entry->u.dir;
+
+		inode->i_blocks = 0;
+		inode->i_size = hdir->files + hdir->dirs + 3;
+		inode->i_mode = S_IRWXUGO | S_IFDIR;
+		HFS_I(inode)->dir_size = 1;
+		if (type == HFS_NAT_NDIR) {
+			inode->i_nlink = hdir->dirs + 3;
+			inode->i_op = &hfs_nat_ndir_inode_operations;
+			HFS_I(inode)->file_type = HFS_NAT_NORM;
+		} else if (type == HFS_NAT_HDIR) {
+			inode->i_nlink = 2;
+			inode->i_op = &hfs_nat_hdir_inode_operations;
+			HFS_I(inode)->file_type = HFS_NAT_HDR;
+		}
+	}
+}