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-rw-r--r--fs/adfs/inode.c395
1 files changed, 395 insertions, 0 deletions
diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c
new file mode 100644
index 00000000000..a02802a3079
--- /dev/null
+++ b/fs/adfs/inode.c
@@ -0,0 +1,395 @@
+/*
+ * linux/fs/adfs/inode.c
+ *
+ * Copyright (C) 1997-1999 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/adfs_fs.h>
+#include <linux/time.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/smp_lock.h>
+#include <linux/module.h>
+#include <linux/buffer_head.h>
+
+#include "adfs.h"
+
+/*
+ * Lookup/Create a block at offset 'block' into 'inode'. We currently do
+ * not support creation of new blocks, so we return -EIO for this case.
+ */
+static int
+adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh,
+ int create)
+{
+ if (block < 0)
+ goto abort_negative;
+
+ if (!create) {
+ if (block >= inode->i_blocks)
+ goto abort_toobig;
+
+ block = __adfs_block_map(inode->i_sb, inode->i_ino, block);
+ if (block)
+ map_bh(bh, inode->i_sb, block);
+ return 0;
+ }
+ /* don't support allocation of blocks yet */
+ return -EIO;
+
+abort_negative:
+ adfs_error(inode->i_sb, "block %d < 0", block);
+ return -EIO;
+
+abort_toobig:
+ return 0;
+}
+
+static int adfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ return block_write_full_page(page, adfs_get_block, wbc);
+}
+
+static int adfs_readpage(struct file *file, struct page *page)
+{
+ return block_read_full_page(page, adfs_get_block);
+}
+
+static int adfs_prepare_write(struct file *file, struct page *page, unsigned int from, unsigned int to)
+{
+ return cont_prepare_write(page, from, to, adfs_get_block,
+ &ADFS_I(page->mapping->host)->mmu_private);
+}
+
+static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
+{
+ return generic_block_bmap(mapping, block, adfs_get_block);
+}
+
+static struct address_space_operations adfs_aops = {
+ .readpage = adfs_readpage,
+ .writepage = adfs_writepage,
+ .sync_page = block_sync_page,
+ .prepare_write = adfs_prepare_write,
+ .commit_write = generic_commit_write,
+ .bmap = _adfs_bmap
+};
+
+static inline unsigned int
+adfs_filetype(struct inode *inode)
+{
+ unsigned int type;
+
+ if (ADFS_I(inode)->stamped)
+ type = (ADFS_I(inode)->loadaddr >> 8) & 0xfff;
+ else
+ type = (unsigned int) -1;
+
+ return type;
+}
+
+/*
+ * Convert ADFS attributes and filetype to Linux permission.
+ */
+static umode_t
+adfs_atts2mode(struct super_block *sb, struct inode *inode)
+{
+ unsigned int filetype, attr = ADFS_I(inode)->attr;
+ umode_t mode, rmask;
+ struct adfs_sb_info *asb = ADFS_SB(sb);
+
+ if (attr & ADFS_NDA_DIRECTORY) {
+ mode = S_IRUGO & asb->s_owner_mask;
+ return S_IFDIR | S_IXUGO | mode;
+ }
+
+ filetype = adfs_filetype(inode);
+
+ switch (filetype) {
+ case 0xfc0: /* LinkFS */
+ return S_IFLNK|S_IRWXUGO;
+
+ case 0xfe6: /* UnixExec */
+ rmask = S_IRUGO | S_IXUGO;
+ break;
+
+ default:
+ rmask = S_IRUGO;
+ }
+
+ mode = S_IFREG;
+
+ if (attr & ADFS_NDA_OWNER_READ)
+ mode |= rmask & asb->s_owner_mask;
+
+ if (attr & ADFS_NDA_OWNER_WRITE)
+ mode |= S_IWUGO & asb->s_owner_mask;
+
+ if (attr & ADFS_NDA_PUBLIC_READ)
+ mode |= rmask & asb->s_other_mask;
+
+ if (attr & ADFS_NDA_PUBLIC_WRITE)
+ mode |= S_IWUGO & asb->s_other_mask;
+ return mode;
+}
+
+/*
+ * Convert Linux permission to ADFS attribute. We try to do the reverse
+ * of atts2mode, but there is not a 1:1 translation.
+ */
+static int
+adfs_mode2atts(struct super_block *sb, struct inode *inode)
+{
+ umode_t mode;
+ int attr;
+ struct adfs_sb_info *asb = ADFS_SB(sb);
+
+ /* FIXME: should we be able to alter a link? */
+ if (S_ISLNK(inode->i_mode))
+ return ADFS_I(inode)->attr;
+
+ if (S_ISDIR(inode->i_mode))
+ attr = ADFS_NDA_DIRECTORY;
+ else
+ attr = 0;
+
+ mode = inode->i_mode & asb->s_owner_mask;
+ if (mode & S_IRUGO)
+ attr |= ADFS_NDA_OWNER_READ;
+ if (mode & S_IWUGO)
+ attr |= ADFS_NDA_OWNER_WRITE;
+
+ mode = inode->i_mode & asb->s_other_mask;
+ mode &= ~asb->s_owner_mask;
+ if (mode & S_IRUGO)
+ attr |= ADFS_NDA_PUBLIC_READ;
+ if (mode & S_IWUGO)
+ attr |= ADFS_NDA_PUBLIC_WRITE;
+
+ return attr;
+}
+
+/*
+ * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time
+ * referenced to 1 Jan 1900 (til 2248)
+ */
+static void
+adfs_adfs2unix_time(struct timespec *tv, struct inode *inode)
+{
+ unsigned int high, low;
+
+ if (ADFS_I(inode)->stamped == 0)
+ goto cur_time;
+
+ high = ADFS_I(inode)->loadaddr << 24;
+ low = ADFS_I(inode)->execaddr;
+
+ high |= low >> 8;
+ low &= 255;
+
+ /* Files dated pre 01 Jan 1970 00:00:00. */
+ if (high < 0x336e996a)
+ goto too_early;
+
+ /* Files dated post 18 Jan 2038 03:14:05. */
+ if (high >= 0x656e9969)
+ goto too_late;
+
+ /* discard 2208988800 (0x336e996a00) seconds of time */
+ high -= 0x336e996a;
+
+ /* convert 40-bit centi-seconds to 32-bit seconds */
+ tv->tv_sec = (((high % 100) << 8) + low) / 100 + (high / 100 << 8);
+ tv->tv_nsec = 0;
+ return;
+
+ cur_time:
+ *tv = CURRENT_TIME_SEC;
+ return;
+
+ too_early:
+ tv->tv_sec = tv->tv_nsec = 0;
+ return;
+
+ too_late:
+ tv->tv_sec = 0x7ffffffd;
+ tv->tv_nsec = 0;
+ return;
+}
+
+/*
+ * Convert an Unix time to ADFS time. We only do this if the entry has a
+ * time/date stamp already.
+ */
+static void
+adfs_unix2adfs_time(struct inode *inode, unsigned int secs)
+{
+ unsigned int high, low;
+
+ if (ADFS_I(inode)->stamped) {
+ /* convert 32-bit seconds to 40-bit centi-seconds */
+ low = (secs & 255) * 100;
+ high = (secs / 256) * 100 + (low >> 8) + 0x336e996a;
+
+ ADFS_I(inode)->loadaddr = (high >> 24) |
+ (ADFS_I(inode)->loadaddr & ~0xff);
+ ADFS_I(inode)->execaddr = (low & 255) | (high << 8);
+ }
+}
+
+/*
+ * Fill in the inode information from the object information.
+ *
+ * Note that this is an inode-less filesystem, so we can't use the inode
+ * number to reference the metadata on the media. Instead, we use the
+ * inode number to hold the object ID, which in turn will tell us where
+ * the data is held. We also save the parent object ID, and with these
+ * two, we can locate the metadata.
+ *
+ * This does mean that we rely on an objects parent remaining the same at
+ * all times - we cannot cope with a cross-directory rename (yet).
+ */
+struct inode *
+adfs_iget(struct super_block *sb, struct object_info *obj)
+{
+ struct inode *inode;
+
+ inode = new_inode(sb);
+ if (!inode)
+ goto out;
+
+ inode->i_uid = ADFS_SB(sb)->s_uid;
+ inode->i_gid = ADFS_SB(sb)->s_gid;
+ inode->i_ino = obj->file_id;
+ inode->i_size = obj->size;
+ inode->i_nlink = 2;
+ inode->i_blksize = PAGE_SIZE;
+ inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >>
+ sb->s_blocksize_bits;
+
+ /*
+ * we need to save the parent directory ID so that
+ * write_inode can update the directory information
+ * for this file. This will need special handling
+ * for cross-directory renames.
+ */
+ ADFS_I(inode)->parent_id = obj->parent_id;
+ ADFS_I(inode)->loadaddr = obj->loadaddr;
+ ADFS_I(inode)->execaddr = obj->execaddr;
+ ADFS_I(inode)->attr = obj->attr;
+ ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000);
+
+ inode->i_mode = adfs_atts2mode(sb, inode);
+ adfs_adfs2unix_time(&inode->i_mtime, inode);
+ inode->i_atime = inode->i_mtime;
+ inode->i_ctime = inode->i_mtime;
+
+ if (S_ISDIR(inode->i_mode)) {
+ inode->i_op = &adfs_dir_inode_operations;
+ inode->i_fop = &adfs_dir_operations;
+ } else if (S_ISREG(inode->i_mode)) {
+ inode->i_op = &adfs_file_inode_operations;
+ inode->i_fop = &adfs_file_operations;
+ inode->i_mapping->a_ops = &adfs_aops;
+ ADFS_I(inode)->mmu_private = inode->i_size;
+ }
+
+ insert_inode_hash(inode);
+
+out:
+ return inode;
+}
+
+/*
+ * Validate and convert a changed access mode/time to their ADFS equivalents.
+ * adfs_write_inode will actually write the information back to the directory
+ * later.
+ */
+int
+adfs_notify_change(struct dentry *dentry, struct iattr *attr)
+{
+ struct inode *inode = dentry->d_inode;
+ struct super_block *sb = inode->i_sb;
+ unsigned int ia_valid = attr->ia_valid;
+ int error;
+
+ lock_kernel();
+
+ error = inode_change_ok(inode, attr);
+
+ /*
+ * we can't change the UID or GID of any file -
+ * we have a global UID/GID in the superblock
+ */
+ if ((ia_valid & ATTR_UID && attr->ia_uid != ADFS_SB(sb)->s_uid) ||
+ (ia_valid & ATTR_GID && attr->ia_gid != ADFS_SB(sb)->s_gid))
+ error = -EPERM;
+
+ if (error)
+ goto out;
+
+ if (ia_valid & ATTR_SIZE)
+ error = vmtruncate(inode, attr->ia_size);
+
+ if (error)
+ goto out;
+
+ if (ia_valid & ATTR_MTIME) {
+ inode->i_mtime = attr->ia_mtime;
+ adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec);
+ }
+ /*
+ * FIXME: should we make these == to i_mtime since we don't
+ * have the ability to represent them in our filesystem?
+ */
+ if (ia_valid & ATTR_ATIME)
+ inode->i_atime = attr->ia_atime;
+ if (ia_valid & ATTR_CTIME)
+ inode->i_ctime = attr->ia_ctime;
+ if (ia_valid & ATTR_MODE) {
+ ADFS_I(inode)->attr = adfs_mode2atts(sb, inode);
+ inode->i_mode = adfs_atts2mode(sb, inode);
+ }
+
+ /*
+ * FIXME: should we be marking this inode dirty even if
+ * we don't have any metadata to write back?
+ */
+ if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE))
+ mark_inode_dirty(inode);
+out:
+ unlock_kernel();
+ return error;
+}
+
+/*
+ * write an existing inode back to the directory, and therefore the disk.
+ * The adfs-specific inode data has already been updated by
+ * adfs_notify_change()
+ */
+int adfs_write_inode(struct inode *inode, int unused)
+{
+ struct super_block *sb = inode->i_sb;
+ struct object_info obj;
+ int ret;
+
+ lock_kernel();
+ obj.file_id = inode->i_ino;
+ obj.name_len = 0;
+ obj.parent_id = ADFS_I(inode)->parent_id;
+ obj.loadaddr = ADFS_I(inode)->loadaddr;
+ obj.execaddr = ADFS_I(inode)->execaddr;
+ obj.attr = ADFS_I(inode)->attr;
+ obj.size = inode->i_size;
+
+ ret = adfs_dir_update(sb, &obj);
+ unlock_kernel();
+ return ret;
+}
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-26 08:12:22 +0000