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-rw-r--r--fs/omfs/Kconfig14
-rw-r--r--fs/omfs/Makefile5
-rw-r--r--fs/omfs/bitmap.c194
-rw-r--r--fs/omfs/dir.c460
-rw-r--r--fs/omfs/file.c382
-rw-r--r--fs/omfs/inode.c626
-rw-r--r--fs/omfs/omfs.h69
-rw-r--r--fs/omfs/omfs_fs.h83
8 files changed, 1833 insertions, 0 deletions
diff --git a/fs/omfs/Kconfig b/fs/omfs/Kconfig
new file mode 100644
index 000000000..42b2ec35a
--- /dev/null
+++ b/fs/omfs/Kconfig
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config OMFS_FS
+ tristate "SonicBlue Optimized MPEG File System support"
+ depends on BLOCK
+ select CRC_ITU_T
+ help
+ This is the proprietary file system used by the Rio Karma music
+ player and ReplayTV DVR. Despite the name, this filesystem is not
+ more efficient than a standard FS for MPEG files, in fact likely
+ the opposite is true. Say Y if you have either of these devices
+ and wish to mount its disk.
+
+ To compile this file system support as a module, choose M here: the
+ module will be called omfs. If unsure, say N.
diff --git a/fs/omfs/Makefile b/fs/omfs/Makefile
new file mode 100644
index 000000000..ae16fc3d3
--- /dev/null
+++ b/fs/omfs/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_OMFS_FS) += omfs.o
+
+omfs-y := bitmap.o dir.o file.o inode.o
diff --git a/fs/omfs/bitmap.c b/fs/omfs/bitmap.c
new file mode 100644
index 000000000..7147ba6a6
--- /dev/null
+++ b/fs/omfs/bitmap.c
@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/buffer_head.h>
+#include <asm/div64.h>
+#include "omfs.h"
+
+unsigned long omfs_count_free(struct super_block *sb)
+{
+ unsigned int i;
+ unsigned long sum = 0;
+ struct omfs_sb_info *sbi = OMFS_SB(sb);
+ int nbits = sb->s_blocksize * 8;
+
+ for (i = 0; i < sbi->s_imap_size; i++)
+ sum += nbits - bitmap_weight(sbi->s_imap[i], nbits);
+
+ return sum;
+}
+
+/*
+ * Counts the run of zero bits starting at bit up to max.
+ * It handles the case where a run might spill over a buffer.
+ * Called with bitmap lock.
+ */
+static int count_run(unsigned long **addr, int nbits,
+ int addrlen, int bit, int max)
+{
+ int count = 0;
+ int x;
+
+ for (; addrlen > 0; addrlen--, addr++) {
+ x = find_next_bit(*addr, nbits, bit);
+ count += x - bit;
+
+ if (x < nbits || count > max)
+ return min(count, max);
+
+ bit = 0;
+ }
+ return min(count, max);
+}
+
+/*
+ * Sets or clears the run of count bits starting with bit.
+ * Called with bitmap lock.
+ */
+static int set_run(struct super_block *sb, int map,
+ int nbits, int bit, int count, int set)
+{
+ int i;
+ int err;
+ struct buffer_head *bh;
+ struct omfs_sb_info *sbi = OMFS_SB(sb);
+
+ err = -ENOMEM;
+ bh = sb_bread(sb, clus_to_blk(sbi, sbi->s_bitmap_ino) + map);
+ if (!bh)
+ goto out;
+
+ for (i = 0; i < count; i++, bit++) {
+ if (bit >= nbits) {
+ bit = 0;
+ map++;
+
+ mark_buffer_dirty(bh);
+ brelse(bh);
+ bh = sb_bread(sb,
+ clus_to_blk(sbi, sbi->s_bitmap_ino) + map);
+ if (!bh)
+ goto out;
+ }
+ if (set) {
+ set_bit(bit, sbi->s_imap[map]);
+ set_bit(bit, (unsigned long *)bh->b_data);
+ } else {
+ clear_bit(bit, sbi->s_imap[map]);
+ clear_bit(bit, (unsigned long *)bh->b_data);
+ }
+ }
+ mark_buffer_dirty(bh);
+ brelse(bh);
+ err = 0;
+out:
+ return err;
+}
+
+/*
+ * Tries to allocate exactly one block. Returns true if successful.
+ */
+int omfs_allocate_block(struct super_block *sb, u64 block)
+{
+ struct buffer_head *bh;
+ struct omfs_sb_info *sbi = OMFS_SB(sb);
+ int bits_per_entry = 8 * sb->s_blocksize;
+ unsigned int map, bit;
+ int ret = 0;
+ u64 tmp;
+
+ tmp = block;
+ bit = do_div(tmp, bits_per_entry);
+ map = tmp;
+
+ mutex_lock(&sbi->s_bitmap_lock);
+ if (map >= sbi->s_imap_size || test_and_set_bit(bit, sbi->s_imap[map]))
+ goto out;
+
+ if (sbi->s_bitmap_ino > 0) {
+ bh = sb_bread(sb, clus_to_blk(sbi, sbi->s_bitmap_ino) + map);
+ if (!bh)
+ goto out;
+
+ set_bit(bit, (unsigned long *)bh->b_data);
+ mark_buffer_dirty(bh);
+ brelse(bh);
+ }
+ ret = 1;
+out:
+ mutex_unlock(&sbi->s_bitmap_lock);
+ return ret;
+}
+
+
+/*
+ * Tries to allocate a set of blocks. The request size depends on the
+ * type: for inodes, we must allocate sbi->s_mirrors blocks, and for file
+ * blocks, we try to allocate sbi->s_clustersize, but can always get away
+ * with just one block.
+ */
+int omfs_allocate_range(struct super_block *sb,
+ int min_request,
+ int max_request,
+ u64 *return_block,
+ int *return_size)
+{
+ struct omfs_sb_info *sbi = OMFS_SB(sb);
+ int bits_per_entry = 8 * sb->s_blocksize;
+ int ret = 0;
+ int i, run, bit;
+
+ mutex_lock(&sbi->s_bitmap_lock);
+ for (i = 0; i < sbi->s_imap_size; i++) {
+ bit = 0;
+ while (bit < bits_per_entry) {
+ bit = find_next_zero_bit(sbi->s_imap[i], bits_per_entry,
+ bit);
+
+ if (bit == bits_per_entry)
+ break;
+
+ run = count_run(&sbi->s_imap[i], bits_per_entry,
+ sbi->s_imap_size-i, bit, max_request);
+
+ if (run >= min_request)
+ goto found;
+ bit += run;
+ }
+ }
+ ret = -ENOSPC;
+ goto out;
+
+found:
+ *return_block = (u64) i * bits_per_entry + bit;
+ *return_size = run;
+ ret = set_run(sb, i, bits_per_entry, bit, run, 1);
+
+out:
+ mutex_unlock(&sbi->s_bitmap_lock);
+ return ret;
+}
+
+/*
+ * Clears count bits starting at a given block.
+ */
+int omfs_clear_range(struct super_block *sb, u64 block, int count)
+{
+ struct omfs_sb_info *sbi = OMFS_SB(sb);
+ int bits_per_entry = 8 * sb->s_blocksize;
+ u64 tmp;
+ unsigned int map, bit;
+ int ret;
+
+ tmp = block;
+ bit = do_div(tmp, bits_per_entry);
+ map = tmp;
+
+ if (map >= sbi->s_imap_size)
+ return 0;
+
+ mutex_lock(&sbi->s_bitmap_lock);
+ ret = set_run(sb, map, bits_per_entry, bit, count, 0);
+ mutex_unlock(&sbi->s_bitmap_lock);
+ return ret;
+}
diff --git a/fs/omfs/dir.c b/fs/omfs/dir.c
new file mode 100644
index 000000000..a0f45651f
--- /dev/null
+++ b/fs/omfs/dir.c
@@ -0,0 +1,460 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * OMFS (as used by RIO Karma) directory operations.
+ * Copyright (C) 2005 Bob Copeland <me@bobcopeland.com>
+ */
+
+#include <linux/fs.h>
+#include <linux/ctype.h>
+#include <linux/buffer_head.h>
+#include "omfs.h"
+
+static int omfs_hash(const char *name, int namelen, int mod)
+{
+ int i, hash = 0;
+ for (i = 0; i < namelen; i++)
+ hash ^= tolower(name[i]) << (i % 24);
+ return hash % mod;
+}
+
+/*
+ * Finds the bucket for a given name and reads the containing block;
+ * *ofs is set to the offset of the first list entry.
+ */
+static struct buffer_head *omfs_get_bucket(struct inode *dir,
+ const char *name, int namelen, int *ofs)
+{
+ int nbuckets = (dir->i_size - OMFS_DIR_START)/8;
+ int bucket = omfs_hash(name, namelen, nbuckets);
+
+ *ofs = OMFS_DIR_START + bucket * 8;
+ return omfs_bread(dir->i_sb, dir->i_ino);
+}
+
+static struct buffer_head *omfs_scan_list(struct inode *dir, u64 block,
+ const char *name, int namelen,
+ u64 *prev_block)
+{
+ struct buffer_head *bh;
+ struct omfs_inode *oi;
+ int err = -ENOENT;
+ *prev_block = ~0;
+
+ while (block != ~0) {
+ bh = omfs_bread(dir->i_sb, block);
+ if (!bh) {
+ err = -EIO;
+ goto err;
+ }
+
+ oi = (struct omfs_inode *) bh->b_data;
+ if (omfs_is_bad(OMFS_SB(dir->i_sb), &oi->i_head, block)) {
+ brelse(bh);
+ goto err;
+ }
+
+ if (strncmp(oi->i_name, name, namelen) == 0)
+ return bh;
+
+ *prev_block = block;
+ block = be64_to_cpu(oi->i_sibling);
+ brelse(bh);
+ }
+err:
+ return ERR_PTR(err);
+}
+
+static struct buffer_head *omfs_find_entry(struct inode *dir,
+ const char *name, int namelen)
+{
+ struct buffer_head *bh;
+ int ofs;
+ u64 block, dummy;
+
+ bh = omfs_get_bucket(dir, name, namelen, &ofs);
+ if (!bh)
+ return ERR_PTR(-EIO);
+
+ block = be64_to_cpu(*((__be64 *) &bh->b_data[ofs]));
+ brelse(bh);
+
+ return omfs_scan_list(dir, block, name, namelen, &dummy);
+}
+
+int omfs_make_empty(struct inode *inode, struct super_block *sb)
+{
+ struct omfs_sb_info *sbi = OMFS_SB(sb);
+ struct buffer_head *bh;
+ struct omfs_inode *oi;
+
+ bh = omfs_bread(sb, inode->i_ino);
+ if (!bh)
+ return -ENOMEM;
+
+ memset(bh->b_data, 0, sizeof(struct omfs_inode));
+
+ if (S_ISDIR(inode->i_mode)) {
+ memset(&bh->b_data[OMFS_DIR_START], 0xff,
+ sbi->s_sys_blocksize - OMFS_DIR_START);
+ } else
+ omfs_make_empty_table(bh, OMFS_EXTENT_START);
+
+ oi = (struct omfs_inode *) bh->b_data;
+ oi->i_head.h_self = cpu_to_be64(inode->i_ino);
+ oi->i_sibling = ~cpu_to_be64(0ULL);
+
+ mark_buffer_dirty(bh);
+ brelse(bh);
+ return 0;
+}
+
+static int omfs_add_link(struct dentry *dentry, struct inode *inode)
+{
+ struct inode *dir = d_inode(dentry->d_parent);
+ const char *name = dentry->d_name.name;
+ int namelen = dentry->d_name.len;
+ struct omfs_inode *oi;
+ struct buffer_head *bh;
+ u64 block;
+ __be64 *entry;
+ int ofs;
+
+ /* just prepend to head of queue in proper bucket */
+ bh = omfs_get_bucket(dir, name, namelen, &ofs);
+ if (!bh)
+ goto out;
+
+ entry = (__be64 *) &bh->b_data[ofs];
+ block = be64_to_cpu(*entry);
+ *entry = cpu_to_be64(inode->i_ino);
+ mark_buffer_dirty(bh);
+ brelse(bh);
+
+ /* now set the sibling and parent pointers on the new inode */
+ bh = omfs_bread(dir->i_sb, inode->i_ino);
+ if (!bh)
+ goto out;
+
+ oi = (struct omfs_inode *) bh->b_data;
+ memcpy(oi->i_name, name, namelen);
+ memset(oi->i_name + namelen, 0, OMFS_NAMELEN - namelen);
+ oi->i_sibling = cpu_to_be64(block);
+ oi->i_parent = cpu_to_be64(dir->i_ino);
+ mark_buffer_dirty(bh);
+ brelse(bh);
+
+ dir->i_ctime = current_time(dir);
+
+ /* mark affected inodes dirty to rebuild checksums */
+ mark_inode_dirty(dir);
+ mark_inode_dirty(inode);
+ return 0;
+out:
+ return -ENOMEM;
+}
+
+static int omfs_delete_entry(struct dentry *dentry)
+{
+ struct inode *dir = d_inode(dentry->d_parent);
+ struct inode *dirty;
+ const char *name = dentry->d_name.name;
+ int namelen = dentry->d_name.len;
+ struct omfs_inode *oi;
+ struct buffer_head *bh, *bh2;
+ __be64 *entry, next;
+ u64 block, prev;
+ int ofs;
+ int err = -ENOMEM;
+
+ /* delete the proper node in the bucket's linked list */
+ bh = omfs_get_bucket(dir, name, namelen, &ofs);
+ if (!bh)
+ goto out;
+
+ entry = (__be64 *) &bh->b_data[ofs];
+ block = be64_to_cpu(*entry);
+
+ bh2 = omfs_scan_list(dir, block, name, namelen, &prev);
+ if (IS_ERR(bh2)) {
+ err = PTR_ERR(bh2);
+ goto out_free_bh;
+ }
+
+ oi = (struct omfs_inode *) bh2->b_data;
+ next = oi->i_sibling;
+ brelse(bh2);
+
+ if (prev != ~0) {
+ /* found in middle of list, get list ptr */
+ brelse(bh);
+ bh = omfs_bread(dir->i_sb, prev);
+ if (!bh)
+ goto out;
+
+ oi = (struct omfs_inode *) bh->b_data;
+ entry = &oi->i_sibling;
+ }
+
+ *entry = next;
+ mark_buffer_dirty(bh);
+
+ if (prev != ~0) {
+ dirty = omfs_iget(dir->i_sb, prev);
+ if (!IS_ERR(dirty)) {
+ mark_inode_dirty(dirty);
+ iput(dirty);
+ }
+ }
+
+ err = 0;
+out_free_bh:
+ brelse(bh);
+out:
+ return err;
+}
+
+static int omfs_dir_is_empty(struct inode *inode)
+{
+ int nbuckets = (inode->i_size - OMFS_DIR_START) / 8;
+ struct buffer_head *bh;
+ u64 *ptr;
+ int i;
+
+ bh = omfs_bread(inode->i_sb, inode->i_ino);
+
+ if (!bh)
+ return 0;
+
+ ptr = (u64 *) &bh->b_data[OMFS_DIR_START];
+
+ for (i = 0; i < nbuckets; i++, ptr++)
+ if (*ptr != ~0)
+ break;
+
+ brelse(bh);
+ return *ptr != ~0;
+}
+
+static int omfs_remove(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = d_inode(dentry);
+ int ret;
+
+
+ if (S_ISDIR(inode->i_mode) &&
+ !omfs_dir_is_empty(inode))
+ return -ENOTEMPTY;
+
+ ret = omfs_delete_entry(dentry);
+ if (ret)
+ return ret;
+
+ clear_nlink(inode);
+ mark_inode_dirty(inode);
+ mark_inode_dirty(dir);
+ return 0;
+}
+
+static int omfs_add_node(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+ int err;
+ struct inode *inode = omfs_new_inode(dir, mode);
+
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ err = omfs_make_empty(inode, dir->i_sb);
+ if (err)
+ goto out_free_inode;
+
+ err = omfs_add_link(dentry, inode);
+ if (err)
+ goto out_free_inode;
+
+ d_instantiate(dentry, inode);
+ return 0;
+
+out_free_inode:
+ iput(inode);
+ return err;
+}
+
+static int omfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+ return omfs_add_node(dir, dentry, mode | S_IFDIR);
+}
+
+static int omfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
+ bool excl)
+{
+ return omfs_add_node(dir, dentry, mode | S_IFREG);
+}
+
+static struct dentry *omfs_lookup(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ struct buffer_head *bh;
+ struct inode *inode = NULL;
+
+ if (dentry->d_name.len > OMFS_NAMELEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ bh = omfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len);
+ if (!IS_ERR(bh)) {
+ struct omfs_inode *oi = (struct omfs_inode *)bh->b_data;
+ ino_t ino = be64_to_cpu(oi->i_head.h_self);
+ brelse(bh);
+ inode = omfs_iget(dir->i_sb, ino);
+ } else if (bh != ERR_PTR(-ENOENT)) {
+ inode = ERR_CAST(bh);
+ }
+ return d_splice_alias(inode, dentry);
+}
+
+/* sanity check block's self pointer */
+int omfs_is_bad(struct omfs_sb_info *sbi, struct omfs_header *header,
+ u64 fsblock)
+{
+ int is_bad;
+ u64 ino = be64_to_cpu(header->h_self);
+ is_bad = ((ino != fsblock) || (ino < sbi->s_root_ino) ||
+ (ino > sbi->s_num_blocks));
+
+ if (is_bad)
+ printk(KERN_WARNING "omfs: bad hash chain detected\n");
+
+ return is_bad;
+}
+
+static bool omfs_fill_chain(struct inode *dir, struct dir_context *ctx,
+ u64 fsblock, int hindex)
+{
+ /* follow chain in this bucket */
+ while (fsblock != ~0) {
+ struct buffer_head *bh = omfs_bread(dir->i_sb, fsblock);
+ struct omfs_inode *oi;
+ u64 self;
+ unsigned char d_type;
+
+ if (!bh)
+ return true;
+
+ oi = (struct omfs_inode *) bh->b_data;
+ if (omfs_is_bad(OMFS_SB(dir->i_sb), &oi->i_head, fsblock)) {
+ brelse(bh);
+ return true;
+ }
+
+ self = fsblock;
+ fsblock = be64_to_cpu(oi->i_sibling);
+
+ /* skip visited nodes */
+ if (hindex) {
+ hindex--;
+ brelse(bh);
+ continue;
+ }
+
+ d_type = (oi->i_type == OMFS_DIR) ? DT_DIR : DT_REG;
+
+ if (!dir_emit(ctx, oi->i_name,
+ strnlen(oi->i_name, OMFS_NAMELEN),
+ self, d_type)) {
+ brelse(bh);
+ return false;
+ }
+ brelse(bh);
+ ctx->pos++;
+ }
+ return true;
+}
+
+static int omfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry,
+ unsigned int flags)
+{
+ struct inode *new_inode = d_inode(new_dentry);
+ struct inode *old_inode = d_inode(old_dentry);
+ int err;
+
+ if (flags & ~RENAME_NOREPLACE)
+ return -EINVAL;
+
+ if (new_inode) {
+ /* overwriting existing file/dir */
+ err = omfs_remove(new_dir, new_dentry);
+ if (err)
+ goto out;
+ }
+
+ /* since omfs locates files by name, we need to unlink _before_
+ * adding the new link or we won't find the old one */
+ err = omfs_delete_entry(old_dentry);
+ if (err)
+ goto out;
+
+ mark_inode_dirty(old_dir);
+ err = omfs_add_link(new_dentry, old_inode);
+ if (err)
+ goto out;
+
+ old_inode->i_ctime = current_time(old_inode);
+ mark_inode_dirty(old_inode);
+out:
+ return err;
+}
+
+static int omfs_readdir(struct file *file, struct dir_context *ctx)
+{
+ struct inode *dir = file_inode(file);
+ struct buffer_head *bh;
+ __be64 *p;
+ unsigned int hchain, hindex;
+ int nbuckets;
+
+ if (ctx->pos >> 32)
+ return -EINVAL;
+
+ if (ctx->pos < 1 << 20) {
+ if (!dir_emit_dots(file, ctx))
+ return 0;
+ ctx->pos = 1 << 20;
+ }
+
+ nbuckets = (dir->i_size - OMFS_DIR_START) / 8;
+
+ /* high 12 bits store bucket + 1 and low 20 bits store hash index */
+ hchain = (ctx->pos >> 20) - 1;
+ hindex = ctx->pos & 0xfffff;
+
+ bh = omfs_bread(dir->i_sb, dir->i_ino);
+ if (!bh)
+ return -EINVAL;
+
+ p = (__be64 *)(bh->b_data + OMFS_DIR_START) + hchain;
+
+ for (; hchain < nbuckets; hchain++) {
+ __u64 fsblock = be64_to_cpu(*p++);
+ if (!omfs_fill_chain(dir, ctx, fsblock, hindex))
+ break;
+ hindex = 0;
+ ctx->pos = (hchain+2) << 20;
+ }
+ brelse(bh);
+ return 0;
+}
+
+const struct inode_operations omfs_dir_inops = {
+ .lookup = omfs_lookup,
+ .mkdir = omfs_mkdir,
+ .rename = omfs_rename,
+ .create = omfs_create,
+ .unlink = omfs_remove,
+ .rmdir = omfs_remove,
+};
+
+const struct file_operations omfs_dir_operations = {
+ .read = generic_read_dir,
+ .iterate_shared = omfs_readdir,
+ .llseek = generic_file_llseek,
+};
diff --git a/fs/omfs/file.c b/fs/omfs/file.c
new file mode 100644
index 000000000..2c7b70ee1
--- /dev/null
+++ b/fs/omfs/file.c
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * OMFS (as used by RIO Karma) file operations.
+ * Copyright (C) 2005 Bob Copeland <me@bobcopeland.com>
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include "omfs.h"
+
+static u32 omfs_max_extents(struct omfs_sb_info *sbi, int offset)
+{
+ return (sbi->s_sys_blocksize - offset -
+ sizeof(struct omfs_extent)) /
+ sizeof(struct omfs_extent_entry) + 1;
+}
+
+void omfs_make_empty_table(struct buffer_head *bh, int offset)
+{
+ struct omfs_extent *oe = (struct omfs_extent *) &bh->b_data[offset];
+
+ oe->e_next = ~cpu_to_be64(0ULL);
+ oe->e_extent_count = cpu_to_be32(1),
+ oe->e_fill = cpu_to_be32(0x22),
+ oe->e_entry.e_cluster = ~cpu_to_be64(0ULL);
+ oe->e_entry.e_blocks = ~cpu_to_be64(0ULL);
+}
+
+int omfs_shrink_inode(struct inode *inode)
+{
+ struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
+ struct omfs_extent *oe;
+ struct omfs_extent_entry *entry;
+ struct buffer_head *bh;
+ u64 next, last;
+ u32 extent_count;
+ u32 max_extents;
+ int ret;
+
+ /* traverse extent table, freeing each entry that is greater
+ * than inode->i_size;
+ */
+ next = inode->i_ino;
+
+ /* only support truncate -> 0 for now */
+ ret = -EIO;
+ if (inode->i_size != 0)
+ goto out;
+
+ bh = omfs_bread(inode->i_sb, next);
+ if (!bh)
+ goto out;
+
+ oe = (struct omfs_extent *)(&bh->b_data[OMFS_EXTENT_START]);
+ max_extents = omfs_max_extents(sbi, OMFS_EXTENT_START);
+
+ for (;;) {
+
+ if (omfs_is_bad(sbi, (struct omfs_header *) bh->b_data, next))
+ goto out_brelse;
+
+ extent_count = be32_to_cpu(oe->e_extent_count);
+
+ if (extent_count > max_extents)
+ goto out_brelse;
+
+ last = next;
+ next = be64_to_cpu(oe->e_next);
+ entry = &oe->e_entry;
+
+ /* ignore last entry as it is the terminator */
+ for (; extent_count > 1; extent_count--) {
+ u64 start, count;
+ start = be64_to_cpu(entry->e_cluster);
+ count = be64_to_cpu(entry->e_blocks);
+
+ omfs_clear_range(inode->i_sb, start, (int) count);
+ entry++;
+ }
+ omfs_make_empty_table(bh, (char *) oe - bh->b_data);
+ mark_buffer_dirty(bh);
+ brelse(bh);
+
+ if (last != inode->i_ino)
+ omfs_clear_range(inode->i_sb, last, sbi->s_mirrors);
+
+ if (next == ~0)
+ break;
+
+ bh = omfs_bread(inode->i_sb, next);
+ if (!bh)
+ goto out;
+ oe = (struct omfs_extent *) (&bh->b_data[OMFS_EXTENT_CONT]);
+ max_extents = omfs_max_extents(sbi, OMFS_EXTENT_CONT);
+ }
+ ret = 0;
+out:
+ return ret;
+out_brelse:
+ brelse(bh);
+ return ret;
+}
+
+static void omfs_truncate(struct inode *inode)
+{
+ omfs_shrink_inode(inode);
+ mark_inode_dirty(inode);
+}
+
+/*
+ * Add new blocks to the current extent, or create new entries/continuations
+ * as necessary.
+ */
+static int omfs_grow_extent(struct inode *inode, struct omfs_extent *oe,
+ u64 *ret_block)
+{
+ struct omfs_extent_entry *terminator;
+ struct omfs_extent_entry *entry = &oe->e_entry;
+ struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
+ u32 extent_count = be32_to_cpu(oe->e_extent_count);
+ u64 new_block = 0;
+ u32 max_count;
+ int new_count;
+ int ret = 0;
+
+ /* reached the end of the extent table with no blocks mapped.
+ * there are three possibilities for adding: grow last extent,
+ * add a new extent to the current extent table, and add a
+ * continuation inode. in last two cases need an allocator for
+ * sbi->s_cluster_size
+ */
+
+ /* TODO: handle holes */
+
+ /* should always have a terminator */
+ if (extent_count < 1)
+ return -EIO;
+
+ /* trivially grow current extent, if next block is not taken */
+ terminator = entry + extent_count - 1;
+ if (extent_count > 1) {
+ entry = terminator-1;
+ new_block = be64_to_cpu(entry->e_cluster) +
+ be64_to_cpu(entry->e_blocks);
+
+ if (omfs_allocate_block(inode->i_sb, new_block)) {
+ be64_add_cpu(&entry->e_blocks, 1);
+ terminator->e_blocks = ~(cpu_to_be64(
+ be64_to_cpu(~terminator->e_blocks) + 1));
+ goto out;
+ }
+ }
+ max_count = omfs_max_extents(sbi, OMFS_EXTENT_START);
+
+ /* TODO: add a continuation block here */
+ if (be32_to_cpu(oe->e_extent_count) > max_count-1)
+ return -EIO;
+
+ /* try to allocate a new cluster */
+ ret = omfs_allocate_range(inode->i_sb, 1, sbi->s_clustersize,
+ &new_block, &new_count);
+ if (ret)
+ goto out_fail;
+
+ /* copy terminator down an entry */
+ entry = terminator;
+ terminator++;
+ memcpy(terminator, entry, sizeof(struct omfs_extent_entry));
+
+ entry->e_cluster = cpu_to_be64(new_block);
+ entry->e_blocks = cpu_to_be64((u64) new_count);
+
+ terminator->e_blocks = ~(cpu_to_be64(
+ be64_to_cpu(~terminator->e_blocks) + (u64) new_count));
+
+ /* write in new entry */
+ be32_add_cpu(&oe->e_extent_count, 1);
+
+out:
+ *ret_block = new_block;
+out_fail:
+ return ret;
+}
+
+/*
+ * Scans across the directory table for a given file block number.
+ * If block not found, return 0.
+ */
+static sector_t find_block(struct inode *inode, struct omfs_extent_entry *ent,
+ sector_t block, int count, int *left)
+{
+ /* count > 1 because of terminator */
+ sector_t searched = 0;
+ for (; count > 1; count--) {
+ int numblocks = clus_to_blk(OMFS_SB(inode->i_sb),
+ be64_to_cpu(ent->e_blocks));
+
+ if (block >= searched &&
+ block < searched + numblocks) {
+ /*
+ * found it at cluster + (block - searched)
+ * numblocks - (block - searched) is remainder
+ */
+ *left = numblocks - (block - searched);
+ return clus_to_blk(OMFS_SB(inode->i_sb),
+ be64_to_cpu(ent->e_cluster)) +
+ block - searched;
+ }
+ searched += numblocks;
+ ent++;
+ }
+ return 0;
+}
+
+static int omfs_get_block(struct inode *inode, sector_t block,
+ struct buffer_head *bh_result, int create)
+{
+ struct buffer_head *bh;
+ sector_t next, offset;
+ int ret;
+ u64 new_block;
+ u32 max_extents;
+ int extent_count;
+ struct omfs_extent *oe;
+ struct omfs_extent_entry *entry;
+ struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
+ int max_blocks = bh_result->b_size >> inode->i_blkbits;
+ int remain;
+
+ ret = -EIO;
+ bh = omfs_bread(inode->i_sb, inode->i_ino);
+ if (!bh)
+ goto out;
+
+ oe = (struct omfs_extent *)(&bh->b_data[OMFS_EXTENT_START]);
+ max_extents = omfs_max_extents(sbi, OMFS_EXTENT_START);
+ next = inode->i_ino;
+
+ for (;;) {
+
+ if (omfs_is_bad(sbi, (struct omfs_header *) bh->b_data, next))
+ goto out_brelse;
+
+ extent_count = be32_to_cpu(oe->e_extent_count);
+ next = be64_to_cpu(oe->e_next);
+ entry = &oe->e_entry;
+
+ if (extent_count > max_extents)
+ goto out_brelse;
+
+ offset = find_block(inode, entry, block, extent_count, &remain);
+ if (offset > 0) {
+ ret = 0;
+ map_bh(bh_result, inode->i_sb, offset);
+ if (remain > max_blocks)
+ remain = max_blocks;
+ bh_result->b_size = (remain << inode->i_blkbits);
+ goto out_brelse;
+ }
+ if (next == ~0)
+ break;
+
+ brelse(bh);
+ bh = omfs_bread(inode->i_sb, next);
+ if (!bh)
+ goto out;
+ oe = (struct omfs_extent *) (&bh->b_data[OMFS_EXTENT_CONT]);
+ max_extents = omfs_max_extents(sbi, OMFS_EXTENT_CONT);
+ }
+ if (create) {
+ ret = omfs_grow_extent(inode, oe, &new_block);
+ if (ret == 0) {
+ mark_buffer_dirty(bh);
+ mark_inode_dirty(inode);
+ map_bh(bh_result, inode->i_sb,
+ clus_to_blk(sbi, new_block));
+ }
+ }
+out_brelse:
+ brelse(bh);
+out:
+ return ret;
+}
+
+static int omfs_readpage(struct file *file, struct page *page)
+{
+ return block_read_full_page(page, omfs_get_block);
+}
+
+static void omfs_readahead(struct readahead_control *rac)
+{
+ mpage_readahead(rac, omfs_get_block);
+}
+
+static int omfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ return block_write_full_page(page, omfs_get_block, wbc);
+}
+
+static int
+omfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+ return mpage_writepages(mapping, wbc, omfs_get_block);
+}
+
+static void omfs_write_failed(struct address_space *mapping, loff_t to)
+{
+ struct inode *inode = mapping->host;
+
+ if (to > inode->i_size) {
+ truncate_pagecache(inode, inode->i_size);
+ omfs_truncate(inode);
+ }
+}
+
+static int omfs_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ int ret;
+
+ ret = block_write_begin(mapping, pos, len, flags, pagep,
+ omfs_get_block);
+ if (unlikely(ret))
+ omfs_write_failed(mapping, pos + len);
+
+ return ret;
+}
+
+static sector_t omfs_bmap(struct address_space *mapping, sector_t block)
+{
+ return generic_block_bmap(mapping, block, omfs_get_block);
+}
+
+const struct file_operations omfs_file_operations = {
+ .llseek = generic_file_llseek,
+ .read_iter = generic_file_read_iter,
+ .write_iter = generic_file_write_iter,
+ .mmap = generic_file_mmap,
+ .fsync = generic_file_fsync,
+ .splice_read = generic_file_splice_read,
+};
+
+static int omfs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ struct inode *inode = d_inode(dentry);
+ int error;
+
+ error = setattr_prepare(dentry, attr);
+ if (error)
+ return error;
+
+ if ((attr->ia_valid & ATTR_SIZE) &&
+ attr->ia_size != i_size_read(inode)) {
+ error = inode_newsize_ok(inode, attr->ia_size);
+ if (error)
+ return error;
+ truncate_setsize(inode, attr->ia_size);
+ omfs_truncate(inode);
+ }
+
+ setattr_copy(inode, attr);
+ mark_inode_dirty(inode);
+ return 0;
+}
+
+const struct inode_operations omfs_file_inops = {
+ .setattr = omfs_setattr,
+};
+
+const struct address_space_operations omfs_aops = {
+ .readpage = omfs_readpage,
+ .readahead = omfs_readahead,
+ .writepage = omfs_writepage,
+ .writepages = omfs_writepages,
+ .write_begin = omfs_write_begin,
+ .write_end = generic_write_end,
+ .bmap = omfs_bmap,
+};
+
diff --git a/fs/omfs/inode.c b/fs/omfs/inode.c
new file mode 100644
index 000000000..ce93ccca8
--- /dev/null
+++ b/fs/omfs/inode.c
@@ -0,0 +1,626 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Optimized MPEG FS - inode and super operations.
+ * Copyright (C) 2006 Bob Copeland <me@bobcopeland.com>
+ */
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/vfs.h>
+#include <linux/cred.h>
+#include <linux/parser.h>
+#include <linux/buffer_head.h>
+#include <linux/vmalloc.h>
+#include <linux/writeback.h>
+#include <linux/seq_file.h>
+#include <linux/crc-itu-t.h>
+#include "omfs.h"
+
+MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>");
+MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux");
+MODULE_LICENSE("GPL");
+
+struct buffer_head *omfs_bread(struct super_block *sb, sector_t block)
+{
+ struct omfs_sb_info *sbi = OMFS_SB(sb);
+ if (block >= sbi->s_num_blocks)
+ return NULL;
+
+ return sb_bread(sb, clus_to_blk(sbi, block));
+}
+
+struct inode *omfs_new_inode(struct inode *dir, umode_t mode)
+{
+ struct inode *inode;
+ u64 new_block;
+ int err;
+ int len;
+ struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb);
+
+ inode = new_inode(dir->i_sb);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors,
+ &new_block, &len);
+ if (err)
+ goto fail;
+
+ inode->i_ino = new_block;
+ inode_init_owner(inode, NULL, mode);
+ inode->i_mapping->a_ops = &omfs_aops;
+
+ inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+ switch (mode & S_IFMT) {
+ case S_IFDIR:
+ inode->i_op = &omfs_dir_inops;
+ inode->i_fop = &omfs_dir_operations;
+ inode->i_size = sbi->s_sys_blocksize;
+ inc_nlink(inode);
+ break;
+ case S_IFREG:
+ inode->i_op = &omfs_file_inops;
+ inode->i_fop = &omfs_file_operations;
+ inode->i_size = 0;
+ break;
+ }
+
+ insert_inode_hash(inode);
+ mark_inode_dirty(inode);
+ return inode;
+fail:
+ make_bad_inode(inode);
+ iput(inode);
+ return ERR_PTR(err);
+}
+
+/*
+ * Update the header checksums for a dirty inode based on its contents.
+ * Caller is expected to hold the buffer head underlying oi and mark it
+ * dirty.
+ */
+static void omfs_update_checksums(struct omfs_inode *oi)
+{
+ int xor, i, ofs = 0, count;
+ u16 crc = 0;
+ unsigned char *ptr = (unsigned char *) oi;
+
+ count = be32_to_cpu(oi->i_head.h_body_size);
+ ofs = sizeof(struct omfs_header);
+
+ crc = crc_itu_t(crc, ptr + ofs, count);
+ oi->i_head.h_crc = cpu_to_be16(crc);
+
+ xor = ptr[0];
+ for (i = 1; i < OMFS_XOR_COUNT; i++)
+ xor ^= ptr[i];
+
+ oi->i_head.h_check_xor = xor;
+}
+
+static int __omfs_write_inode(struct inode *inode, int wait)
+{
+ struct omfs_inode *oi;
+ struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
+ struct buffer_head *bh, *bh2;
+ u64 ctime;
+ int i;
+ int ret = -EIO;
+ int sync_failed = 0;
+
+ /* get current inode since we may have written sibling ptrs etc. */
+ bh = omfs_bread(inode->i_sb, inode->i_ino);
+ if (!bh)
+ goto out;
+
+ oi = (struct omfs_inode *) bh->b_data;
+
+ oi->i_head.h_self = cpu_to_be64(inode->i_ino);
+ if (S_ISDIR(inode->i_mode))
+ oi->i_type = OMFS_DIR;
+ else if (S_ISREG(inode->i_mode))
+ oi->i_type = OMFS_FILE;
+ else {
+ printk(KERN_WARNING "omfs: unknown file type: %d\n",
+ inode->i_mode);
+ goto out_brelse;
+ }
+
+ oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize -
+ sizeof(struct omfs_header));
+ oi->i_head.h_version = 1;
+ oi->i_head.h_type = OMFS_INODE_NORMAL;
+ oi->i_head.h_magic = OMFS_IMAGIC;
+ oi->i_size = cpu_to_be64(inode->i_size);
+
+ ctime = inode->i_ctime.tv_sec * 1000LL +
+ ((inode->i_ctime.tv_nsec + 999)/1000);
+ oi->i_ctime = cpu_to_be64(ctime);
+
+ omfs_update_checksums(oi);
+
+ mark_buffer_dirty(bh);
+ if (wait) {
+ sync_dirty_buffer(bh);
+ if (buffer_req(bh) && !buffer_uptodate(bh))
+ sync_failed = 1;
+ }
+
+ /* if mirroring writes, copy to next fsblock */
+ for (i = 1; i < sbi->s_mirrors; i++) {
+ bh2 = omfs_bread(inode->i_sb, inode->i_ino + i);
+ if (!bh2)
+ goto out_brelse;
+
+ memcpy(bh2->b_data, bh->b_data, bh->b_size);
+ mark_buffer_dirty(bh2);
+ if (wait) {
+ sync_dirty_buffer(bh2);
+ if (buffer_req(bh2) && !buffer_uptodate(bh2))
+ sync_failed = 1;
+ }
+ brelse(bh2);
+ }
+ ret = (sync_failed) ? -EIO : 0;
+out_brelse:
+ brelse(bh);
+out:
+ return ret;
+}
+
+static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+ return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
+}
+
+int omfs_sync_inode(struct inode *inode)
+{
+ return __omfs_write_inode(inode, 1);
+}
+
+/*
+ * called when an entry is deleted, need to clear the bits in the
+ * bitmaps.
+ */
+static void omfs_evict_inode(struct inode *inode)
+{
+ truncate_inode_pages_final(&inode->i_data);
+ clear_inode(inode);
+
+ if (inode->i_nlink)
+ return;
+
+ if (S_ISREG(inode->i_mode)) {
+ inode->i_size = 0;
+ omfs_shrink_inode(inode);
+ }
+
+ omfs_clear_range(inode->i_sb, inode->i_ino, 2);
+}
+
+struct inode *omfs_iget(struct super_block *sb, ino_t ino)
+{
+ struct omfs_sb_info *sbi = OMFS_SB(sb);
+ struct omfs_inode *oi;
+ struct buffer_head *bh;
+ u64 ctime;
+ unsigned long nsecs;
+ struct inode *inode;
+
+ inode = iget_locked(sb, ino);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+ if (!(inode->i_state & I_NEW))
+ return inode;
+
+ bh = omfs_bread(inode->i_sb, ino);
+ if (!bh)
+ goto iget_failed;
+
+ oi = (struct omfs_inode *)bh->b_data;
+
+ /* check self */
+ if (ino != be64_to_cpu(oi->i_head.h_self))
+ goto fail_bh;
+
+ inode->i_uid = sbi->s_uid;
+ inode->i_gid = sbi->s_gid;
+
+ ctime = be64_to_cpu(oi->i_ctime);
+ nsecs = do_div(ctime, 1000) * 1000L;
+
+ inode->i_atime.tv_sec = ctime;
+ inode->i_mtime.tv_sec = ctime;
+ inode->i_ctime.tv_sec = ctime;
+ inode->i_atime.tv_nsec = nsecs;
+ inode->i_mtime.tv_nsec = nsecs;
+ inode->i_ctime.tv_nsec = nsecs;
+
+ inode->i_mapping->a_ops = &omfs_aops;
+
+ switch (oi->i_type) {
+ case OMFS_DIR:
+ inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
+ inode->i_op = &omfs_dir_inops;
+ inode->i_fop = &omfs_dir_operations;
+ inode->i_size = sbi->s_sys_blocksize;
+ inc_nlink(inode);
+ break;
+ case OMFS_FILE:
+ inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
+ inode->i_fop = &omfs_file_operations;
+ inode->i_size = be64_to_cpu(oi->i_size);
+ break;
+ }
+ brelse(bh);
+ unlock_new_inode(inode);
+ return inode;
+fail_bh:
+ brelse(bh);
+iget_failed:
+ iget_failed(inode);
+ return ERR_PTR(-EIO);
+}
+
+static void omfs_put_super(struct super_block *sb)
+{
+ struct omfs_sb_info *sbi = OMFS_SB(sb);
+ kfree(sbi->s_imap);
+ kfree(sbi);
+ sb->s_fs_info = NULL;
+}
+
+static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct super_block *s = dentry->d_sb;
+ struct omfs_sb_info *sbi = OMFS_SB(s);
+ u64 id = huge_encode_dev(s->s_bdev->bd_dev);
+
+ buf->f_type = OMFS_MAGIC;
+ buf->f_bsize = sbi->s_blocksize;
+ buf->f_blocks = sbi->s_num_blocks;
+ buf->f_files = sbi->s_num_blocks;
+ buf->f_namelen = OMFS_NAMELEN;
+ buf->f_fsid = u64_to_fsid(id);
+
+ buf->f_bfree = buf->f_bavail = buf->f_ffree =
+ omfs_count_free(s);
+
+ return 0;
+}
+
+/*
+ * Display the mount options in /proc/mounts.
+ */
+static int omfs_show_options(struct seq_file *m, struct dentry *root)
+{
+ struct omfs_sb_info *sbi = OMFS_SB(root->d_sb);
+ umode_t cur_umask = current_umask();
+
+ if (!uid_eq(sbi->s_uid, current_uid()))
+ seq_printf(m, ",uid=%u",
+ from_kuid_munged(&init_user_ns, sbi->s_uid));
+ if (!gid_eq(sbi->s_gid, current_gid()))
+ seq_printf(m, ",gid=%u",
+ from_kgid_munged(&init_user_ns, sbi->s_gid));
+
+ if (sbi->s_dmask == sbi->s_fmask) {
+ if (sbi->s_fmask != cur_umask)
+ seq_printf(m, ",umask=%o", sbi->s_fmask);
+ } else {
+ if (sbi->s_dmask != cur_umask)
+ seq_printf(m, ",dmask=%o", sbi->s_dmask);
+ if (sbi->s_fmask != cur_umask)
+ seq_printf(m, ",fmask=%o", sbi->s_fmask);
+ }
+
+ return 0;
+}
+
+static const struct super_operations omfs_sops = {
+ .write_inode = omfs_write_inode,
+ .evict_inode = omfs_evict_inode,
+ .put_super = omfs_put_super,
+ .statfs = omfs_statfs,
+ .show_options = omfs_show_options,
+};
+
+/*
+ * For Rio Karma, there is an on-disk free bitmap whose location is
+ * stored in the root block. For ReplayTV, there is no such free bitmap
+ * so we have to walk the tree. Both inodes and file data are allocated
+ * from the same map. This array can be big (300k) so we allocate
+ * in units of the blocksize.
+ */
+static int omfs_get_imap(struct super_block *sb)
+{
+ unsigned int bitmap_size, array_size;
+ int count;
+ struct omfs_sb_info *sbi = OMFS_SB(sb);
+ struct buffer_head *bh;
+ unsigned long **ptr;
+ sector_t block;
+
+ bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
+ array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
+
+ if (sbi->s_bitmap_ino == ~0ULL)
+ goto out;
+
+ sbi->s_imap_size = array_size;
+ sbi->s_imap = kcalloc(array_size, sizeof(unsigned long *), GFP_KERNEL);
+ if (!sbi->s_imap)
+ goto nomem;
+
+ block = clus_to_blk(sbi, sbi->s_bitmap_ino);
+ if (block >= sbi->s_num_blocks)
+ goto nomem;
+
+ ptr = sbi->s_imap;
+ for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
+ bh = sb_bread(sb, block++);
+ if (!bh)
+ goto nomem_free;
+ *ptr = kmemdup(bh->b_data, sb->s_blocksize, GFP_KERNEL);
+ if (!*ptr) {
+ brelse(bh);
+ goto nomem_free;
+ }
+ if (count < sb->s_blocksize)
+ memset((void *)*ptr + count, 0xff,
+ sb->s_blocksize - count);
+ brelse(bh);
+ ptr++;
+ }
+out:
+ return 0;
+
+nomem_free:
+ for (count = 0; count < array_size; count++)
+ kfree(sbi->s_imap[count]);
+
+ kfree(sbi->s_imap);
+nomem:
+ sbi->s_imap = NULL;
+ sbi->s_imap_size = 0;
+ return -ENOMEM;
+}
+
+enum {
+ Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask, Opt_err
+};
+
+static const match_table_t tokens = {
+ {Opt_uid, "uid=%u"},
+ {Opt_gid, "gid=%u"},
+ {Opt_umask, "umask=%o"},
+ {Opt_dmask, "dmask=%o"},
+ {Opt_fmask, "fmask=%o"},
+ {Opt_err, NULL},
+};
+
+static int parse_options(char *options, struct omfs_sb_info *sbi)
+{
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+
+ if (!options)
+ return 1;
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+ if (!*p)
+ continue;
+
+ token = match_token(p, tokens, args);
+ switch (token) {
+ case Opt_uid:
+ if (match_int(&args[0], &option))
+ return 0;
+ sbi->s_uid = make_kuid(current_user_ns(), option);
+ if (!uid_valid(sbi->s_uid))
+ return 0;
+ break;
+ case Opt_gid:
+ if (match_int(&args[0], &option))
+ return 0;
+ sbi->s_gid = make_kgid(current_user_ns(), option);
+ if (!gid_valid(sbi->s_gid))
+ return 0;
+ break;
+ case Opt_umask:
+ if (match_octal(&args[0], &option))
+ return 0;
+ sbi->s_fmask = sbi->s_dmask = option;
+ break;
+ case Opt_dmask:
+ if (match_octal(&args[0], &option))
+ return 0;
+ sbi->s_dmask = option;
+ break;
+ case Opt_fmask:
+ if (match_octal(&args[0], &option))
+ return 0;
+ sbi->s_fmask = option;
+ break;
+ default:
+ return 0;
+ }
+ }
+ return 1;
+}
+
+static int omfs_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct buffer_head *bh, *bh2;
+ struct omfs_super_block *omfs_sb;
+ struct omfs_root_block *omfs_rb;
+ struct omfs_sb_info *sbi;
+ struct inode *root;
+ int ret = -EINVAL;
+
+ sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
+ if (!sbi)
+ return -ENOMEM;
+
+ sb->s_fs_info = sbi;
+
+ sbi->s_uid = current_uid();
+ sbi->s_gid = current_gid();
+ sbi->s_dmask = sbi->s_fmask = current_umask();
+
+ if (!parse_options((char *) data, sbi))
+ goto end;
+
+ sb->s_maxbytes = 0xffffffff;
+
+ sb->s_time_gran = NSEC_PER_MSEC;
+ sb->s_time_min = 0;
+ sb->s_time_max = U64_MAX / MSEC_PER_SEC;
+
+ sb_set_blocksize(sb, 0x200);
+
+ bh = sb_bread(sb, 0);
+ if (!bh)
+ goto end;
+
+ omfs_sb = (struct omfs_super_block *)bh->b_data;
+
+ if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
+ if (!silent)
+ printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
+ omfs_sb->s_magic);
+ goto out_brelse_bh;
+ }
+ sb->s_magic = OMFS_MAGIC;
+
+ sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
+ sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
+ sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
+ sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
+ sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
+ mutex_init(&sbi->s_bitmap_lock);
+
+ if (sbi->s_num_blocks > OMFS_MAX_BLOCKS) {
+ printk(KERN_ERR "omfs: sysblock number (%llx) is out of range\n",
+ (unsigned long long)sbi->s_num_blocks);
+ goto out_brelse_bh;
+ }
+
+ if (sbi->s_sys_blocksize > PAGE_SIZE) {
+ printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
+ sbi->s_sys_blocksize);
+ goto out_brelse_bh;
+ }
+
+ if (sbi->s_blocksize < sbi->s_sys_blocksize ||
+ sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
+ printk(KERN_ERR "omfs: block size (%d) is out of range\n",
+ sbi->s_blocksize);
+ goto out_brelse_bh;
+ }
+
+ /*
+ * Use sys_blocksize as the fs block since it is smaller than a
+ * page while the fs blocksize can be larger.
+ */
+ sb_set_blocksize(sb, sbi->s_sys_blocksize);
+
+ /*
+ * ...and the difference goes into a shift. sys_blocksize is always
+ * a power of two factor of blocksize.
+ */
+ sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
+ get_bitmask_order(sbi->s_sys_blocksize);
+
+ bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block));
+ if (!bh2)
+ goto out_brelse_bh;
+
+ omfs_rb = (struct omfs_root_block *)bh2->b_data;
+
+ sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
+ sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
+
+ if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
+ printk(KERN_ERR "omfs: block count discrepancy between "
+ "super and root blocks (%llx, %llx)\n",
+ (unsigned long long)sbi->s_num_blocks,
+ (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
+ goto out_brelse_bh2;
+ }
+
+ if (sbi->s_bitmap_ino != ~0ULL &&
+ sbi->s_bitmap_ino > sbi->s_num_blocks) {
+ printk(KERN_ERR "omfs: free space bitmap location is corrupt "
+ "(%llx, total blocks %llx)\n",
+ (unsigned long long) sbi->s_bitmap_ino,
+ (unsigned long long) sbi->s_num_blocks);
+ goto out_brelse_bh2;
+ }
+ if (sbi->s_clustersize < 1 ||
+ sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) {
+ printk(KERN_ERR "omfs: cluster size out of range (%d)",
+ sbi->s_clustersize);
+ goto out_brelse_bh2;
+ }
+
+ ret = omfs_get_imap(sb);
+ if (ret)
+ goto out_brelse_bh2;
+
+ sb->s_op = &omfs_sops;
+
+ root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
+ if (IS_ERR(root)) {
+ ret = PTR_ERR(root);
+ goto out_brelse_bh2;
+ }
+
+ sb->s_root = d_make_root(root);
+ if (!sb->s_root) {
+ ret = -ENOMEM;
+ goto out_brelse_bh2;
+ }
+ printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
+
+ ret = 0;
+out_brelse_bh2:
+ brelse(bh2);
+out_brelse_bh:
+ brelse(bh);
+end:
+ if (ret)
+ kfree(sbi);
+ return ret;
+}
+
+static struct dentry *omfs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return mount_bdev(fs_type, flags, dev_name, data, omfs_fill_super);
+}
+
+static struct file_system_type omfs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "omfs",
+ .mount = omfs_mount,
+ .kill_sb = kill_block_super,
+ .fs_flags = FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("omfs");
+
+static int __init init_omfs_fs(void)
+{
+ return register_filesystem(&omfs_fs_type);
+}
+
+static void __exit exit_omfs_fs(void)
+{
+ unregister_filesystem(&omfs_fs_type);
+}
+
+module_init(init_omfs_fs);
+module_exit(exit_omfs_fs);
diff --git a/fs/omfs/omfs.h b/fs/omfs/omfs.h
new file mode 100644
index 000000000..4008be73d
--- /dev/null
+++ b/fs/omfs/omfs.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _OMFS_H
+#define _OMFS_H
+
+#include <linux/module.h>
+#include <linux/fs.h>
+
+#include "omfs_fs.h"
+
+/* In-memory structures */
+struct omfs_sb_info {
+ u64 s_num_blocks;
+ u64 s_bitmap_ino;
+ u64 s_root_ino;
+ u32 s_blocksize;
+ u32 s_mirrors;
+ u32 s_sys_blocksize;
+ u32 s_clustersize;
+ int s_block_shift;
+ unsigned long **s_imap;
+ int s_imap_size;
+ struct mutex s_bitmap_lock;
+ kuid_t s_uid;
+ kgid_t s_gid;
+ int s_dmask;
+ int s_fmask;
+};
+
+/* convert a cluster number to a scaled block number */
+static inline sector_t clus_to_blk(struct omfs_sb_info *sbi, sector_t block)
+{
+ return block << sbi->s_block_shift;
+}
+
+static inline struct omfs_sb_info *OMFS_SB(struct super_block *sb)
+{
+ return sb->s_fs_info;
+}
+
+/* bitmap.c */
+extern unsigned long omfs_count_free(struct super_block *sb);
+extern int omfs_allocate_block(struct super_block *sb, u64 block);
+extern int omfs_allocate_range(struct super_block *sb, int min_request,
+ int max_request, u64 *return_block, int *return_size);
+extern int omfs_clear_range(struct super_block *sb, u64 block, int count);
+
+/* dir.c */
+extern const struct file_operations omfs_dir_operations;
+extern const struct inode_operations omfs_dir_inops;
+extern int omfs_make_empty(struct inode *inode, struct super_block *sb);
+extern int omfs_is_bad(struct omfs_sb_info *sbi, struct omfs_header *header,
+ u64 fsblock);
+
+/* file.c */
+extern const struct file_operations omfs_file_operations;
+extern const struct inode_operations omfs_file_inops;
+extern const struct address_space_operations omfs_aops;
+extern void omfs_make_empty_table(struct buffer_head *bh, int offset);
+extern int omfs_shrink_inode(struct inode *inode);
+
+/* inode.c */
+extern struct buffer_head *omfs_bread(struct super_block *sb, sector_t block);
+extern struct inode *omfs_iget(struct super_block *sb, ino_t inode);
+extern struct inode *omfs_new_inode(struct inode *dir, umode_t mode);
+extern int omfs_reserve_block(struct super_block *sb, sector_t block);
+extern int omfs_find_empty_block(struct super_block *sb, int mode, ino_t *ino);
+extern int omfs_sync_inode(struct inode *inode);
+
+#endif
diff --git a/fs/omfs/omfs_fs.h b/fs/omfs/omfs_fs.h
new file mode 100644
index 000000000..caecb3d5a
--- /dev/null
+++ b/fs/omfs/omfs_fs.h
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _OMFS_FS_H
+#define _OMFS_FS_H
+
+/* OMFS On-disk structures */
+
+#define OMFS_MAGIC 0xC2993D87
+#define OMFS_IMAGIC 0xD2
+
+#define OMFS_DIR 'D'
+#define OMFS_FILE 'F'
+#define OMFS_INODE_NORMAL 'e'
+#define OMFS_INODE_CONTINUATION 'c'
+#define OMFS_INODE_SYSTEM 's'
+#define OMFS_NAMELEN 256
+#define OMFS_DIR_START 0x1b8
+#define OMFS_EXTENT_START 0x1d0
+#define OMFS_EXTENT_CONT 0x40
+#define OMFS_XOR_COUNT 19
+#define OMFS_MAX_BLOCK_SIZE 8192
+#define OMFS_MAX_CLUSTER_SIZE 8
+#define OMFS_MAX_BLOCKS (1ul << 31)
+
+struct omfs_super_block {
+ char s_fill1[256];
+ __be64 s_root_block; /* block number of omfs_root_block */
+ __be64 s_num_blocks; /* total number of FS blocks */
+ __be32 s_magic; /* OMFS_MAGIC */
+ __be32 s_blocksize; /* size of a block */
+ __be32 s_mirrors; /* # of mirrors of system blocks */
+ __be32 s_sys_blocksize; /* size of non-data blocks */
+};
+
+struct omfs_header {
+ __be64 h_self; /* FS block where this is located */
+ __be32 h_body_size; /* size of useful data after header */
+ __be16 h_crc; /* crc-ccitt of body_size bytes */
+ char h_fill1[2];
+ u8 h_version; /* version, always 1 */
+ char h_type; /* OMFS_INODE_X */
+ u8 h_magic; /* OMFS_IMAGIC */
+ u8 h_check_xor; /* XOR of header bytes before this */
+ __be32 h_fill2;
+};
+
+struct omfs_root_block {
+ struct omfs_header r_head; /* header */
+ __be64 r_fill1;
+ __be64 r_num_blocks; /* total number of FS blocks */
+ __be64 r_root_dir; /* block # of root directory */
+ __be64 r_bitmap; /* block # of free space bitmap */
+ __be32 r_blocksize; /* size of a block */
+ __be32 r_clustersize; /* size allocated for data blocks */
+ __be64 r_mirrors; /* # of mirrors of system blocks */
+ char r_name[OMFS_NAMELEN]; /* partition label */
+};
+
+struct omfs_inode {
+ struct omfs_header i_head; /* header */
+ __be64 i_parent; /* parent containing this inode */
+ __be64 i_sibling; /* next inode in hash bucket */
+ __be64 i_ctime; /* ctime, in milliseconds */
+ char i_fill1[35];
+ char i_type; /* OMFS_[DIR,FILE] */
+ __be32 i_fill2;
+ char i_fill3[64];
+ char i_name[OMFS_NAMELEN]; /* filename */
+ __be64 i_size; /* size of file, in bytes */
+};
+
+struct omfs_extent_entry {
+ __be64 e_cluster; /* start location of a set of blocks */
+ __be64 e_blocks; /* number of blocks after e_cluster */
+};
+
+struct omfs_extent {
+ __be64 e_next; /* next extent table location */
+ __be32 e_extent_count; /* total # extents in this table */
+ __be32 e_fill;
+ struct omfs_extent_entry e_entry; /* start of extent entries */
+};
+
+#endif