omfs: add inode routines
Add basic superblock and inode handling routines for OMFS
Signed-off-by: Bob Copeland <me@xxxxxxxxxxxxxxx>
---
fs/omfs/inode.c | 553 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 553 insertions(+)
Index: linux-2.6/fs/omfs/inode.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/fs/omfs/inode.c 2008-04-26 15:34:08.000000000 -0400
@@ -0,0 +1,553 @@
+/*
+ * Optimized MPEG FS - inode and super operations.
+ * Copyright (C) 2006 Bob Copeland <me@xxxxxxxxxxxxxxx>
+ * Released under GPL v2.
+ */
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/vfs.h>
+#include <linux/parser.h>
+#include <linux/buffer_head.h>
+#include <linux/vmalloc.h>
+#include <linux/crc-itu-t.h>
+#include "omfs.h"
+
+MODULE_AUTHOR("Bob Copeland <me@xxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux");
+MODULE_LICENSE("GPL");
+
+struct inode *omfs_new_inode(struct inode *dir, int 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->i_mode = mode;
+ inode->i_uid = current->fsuid;
+ inode->i_gid = current->fsgid;
+ inode->i_blocks = 0;
+ inode->i_mapping->a_ops = &omfs_aops;
+
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ 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;
+ unsigned int block;
+ u64 ctime;
+ int i;
+ int ret = -EIO;
+ int sync_failed = 0;
+
+ /* get current inode since we may have written sibling ptrs etc. */
+ block = clus_to_blk(sbi, inode->i_ino);
+ bh = sb_bread(inode->i_sb, block);
+ 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 = sb_bread(inode->i_sb, block + i *
+ (sbi->s_blocksize / sbi->s_sys_blocksize));
+ 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;
+}
+
+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_delete_inode(struct inode *inode)
+{
+ truncate_inode_pages(&inode->i_data, 0);
+
+ if (S_ISREG(inode->i_mode)) {
+ inode->i_size = 0;
+ omfs_shrink_inode(inode);
+ }
+
+ omfs_clear_range(inode->i_sb, inode->i_ino, 2);
+ clear_inode(inode);
+}
+
+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;
+ unsigned int block;
+ 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;
+
+ block = clus_to_blk(sbi, ino);
+ bh = sb_bread(inode->i_sb, block);
+ 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 = be32_to_cpu(oi->i_head.h_body_size) +
+ sizeof(struct omfs_header);
+ 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);
+ 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_bfree = buf->f_bavail = buf->f_ffree =
+ omfs_count_free(s);
+ return 0;
+}
+
+static struct super_operations omfs_sops = {
+ .write_inode = omfs_write_inode,
+ .delete_inode = omfs_delete_inode,
+ .put_super = omfs_put_super,
+ .statfs = omfs_statfs,
+ .show_options = generic_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)
+{
+ int bitmap_size;
+ int 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 = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL);
+ if (!sbi->s_imap)
+ goto nomem;
+
+ block = clus_to_blk(sbi, sbi->s_bitmap_ino);
+ 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 = kmalloc(sb->s_blocksize, GFP_KERNEL);
+ if (!*ptr) {
+ brelse(bh);
+ goto nomem_free;
+ }
+ memcpy(*ptr, bh->b_data, sb->s_blocksize);
+ 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
+};
+
+static match_table_t tokens = {
+ {Opt_uid, "uid=%u"},
+ {Opt_gid, "gid=%u"},
+ {Opt_umask, "umask=%o"},
+ {Opt_dmask, "dmask=%o"},
+ {Opt_fmask, "fmask=%o"},
+};
+
+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 = option;
+ break;
+ case Opt_gid:
+ if (match_int(&args[0], &option))
+ return 0;
+ sbi->s_gid = option;
+ 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;
+ sector_t start;
+ int ret = -EINVAL;
+
+ save_mount_options(sb, (char *) data);
+
+ 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->fs->umask;
+
+ if (!parse_options((char *) data, sbi))
+ goto end;
+
+ sb->s_maxbytes = 0xffffffff;
+
+ 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_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);
+
+ start = clus_to_blk(sbi, be64_to_cpu(omfs_sb->s_root_block));
+ bh2 = sb_bread(sb, start);
+ 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",
+ sbi->s_num_blocks, be64_to_cpu(omfs_rb->r_num_blocks));
+ 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_alloc_root(root);
+ if (!sb->s_root) {
+ iput(root);
+ 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:
+ return ret;
+}
+
+static int omfs_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name,
+ void *data, struct vfsmount *m)
+{
+ return get_sb_bdev(fs_type, flags, dev_name, data, omfs_fill_super, m);
+}
+
+static struct file_system_type omfs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "omfs",
+ .get_sb = omfs_get_sb,
+ .kill_sb = kill_block_super,
+ .fs_flags = FS_REQUIRES_DEV,
+};
+
+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);
--
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