[PATCH,RFC] umsdos FS in 2.6.x

From: Randy.Dunlap
Date: Fri Oct 24 2003 - 01:57:04 EST


This patch enables umsdos filesystem to build, although a few things
still need to be fixed, such as:

. updating {acm}time, since those fields changed from time_t to
struct timespec: for backward compatibility, do these fields
need to remain as time_t (i.e., keep the same size) ?

. I kept using a 16-bit dev_t. Does this need to change?
If yes, to 32-bit, or to use whatever size is passed to it?

. fill_super/read_super probably still need a little bit of work,
such as which inode_operations structure to use.

. I'll begin testing it soon.

--
~Randy


> Hi folks,
>
> Does kernel 2.6 supports UMSDOS file system?

Not unless it gets very massive fixes. (--viro)



fs/Kconfig | 6 +--
fs/umsdos/Makefile | 4 +-
fs/umsdos/dir.c | 25 +++++++++------
fs/umsdos/inode.c | 71 ++++++++++++++++++++++++++++++++------------
fs/umsdos/ioctl.c | 17 ++++++----
fs/umsdos/namei.c | 2 +
fs/umsdos/rdir.c | 1
include/linux/umsdos_fs.p | 14 +++-----
include/linux/umsdos_fs_i.h | 4 ++
9 files changed, 96 insertions(+), 48 deletions(-)

diff -Naurp linux-260-test8-efs/include/linux/umsdos_fs_i.h linux-260-test8/include/linux/umsdos_fs_i.h
--- linux-260-test8-efs/include/linux/umsdos_fs_i.h 2003-10-17 14:43:20.000000000 -0700
+++ linux-260-test8/include/linux/umsdos_fs_i.h 2003-10-23 16:13:10.000000000 -0700
@@ -55,4 +55,8 @@ struct umsdos_inode_info {
off_t pos; /* Entry offset in the emd_owner file */
};

+static inline struct umsdos_inode_info *UMSDOS_I(struct inode *inode)
+{
+ return (struct umsdos_inode_info *)inode->u.generic_ip;
+}
#endif
diff -Naurp linux-260-test8-efs/include/linux/umsdos_fs.p linux-260-test8/include/linux/umsdos_fs.p
--- linux-260-test8-efs/include/linux/umsdos_fs.p 2003-10-17 14:43:00.000000000 -0700
+++ linux-260-test8/include/linux/umsdos_fs.p 2003-10-23 23:20:36.000000000 -0700
@@ -37,8 +37,10 @@ void UMSDOS_write_inode (struct inode *,
int UMSDOS_notify_change (struct dentry *, struct iattr *attr);
int umsdos_notify_change_locked(struct dentry *, struct iattr *attr);
void UMSDOS_put_inode (struct inode *);
-int UMSDOS_statfs (struct super_block *, struct statfs *);
-struct super_block *UMSDOS_read_super (struct super_block *, void *, int);
+struct statfs;
+int UMSDOS_statfs (struct super_block *, struct kstatfs *);
+int UMSDOS_read_super (struct super_block *, void *, int,
+ struct inode_operations *, int);
void UMSDOS_put_super (struct super_block *);

void umsdos_setup_dir(struct dentry *);
@@ -74,7 +76,8 @@ int UMSDOS_link (struct dentry *olddentr
struct dentry *dentry);
int UMSDOS_create (struct inode *dir,
struct dentry *dentry,
- int mode);
+ int mode,
+ struct nameidata *nd);

int UMSDOS_mkdir (struct inode *dir,
struct dentry *dentry,
@@ -93,8 +96,3 @@ int UMSDOS_rename (struct inode *old_dir
/* rdir.c 22/03/95 03.31.42 */
struct dentry *umsdos_rlookup_x (struct inode *dir, struct dentry *dentry, int nopseudo);
struct dentry *UMSDOS_rlookup (struct inode *dir, struct dentry *dentry, struct nameidata *nd);
-
-static inline struct umsdos_inode_info *UMSDOS_I(struct inode *inode)
-{
- return &inode->u.umsdos_i;
-}
--- linux-260-test8-efs/fs/Kconfig 2003-10-17 14:43:15.000000000 -0700
+++ linux-260-test8/fs/Kconfig 2003-10-23 13:01:50.000000000 -0700
@@ -621,9 +621,9 @@ config VFAT_FS
vfat.

config UMSDOS_FS
-#dep_tristate ' UMSDOS: Unix-like file system on top of standard MSDOS fs' CONFIG_UMSDOS_FS $CONFIG_MSDOS_FS
-# UMSDOS is temprory broken
- bool
+ tristate ' UMSDOS: Unix-like file system on top of standard MSDOS fs'
+ depends on MSDOS_FS || BROKEN
+# UMSDOS is BROKEN until someone spends some time to fix it
help
Say Y here if you want to run Linux from within an existing DOS
partition of your hard drive. The advantage of this is that you can
diff -Naurp linux-260-test8-efs/fs/umsdos/inode.c linux-260-test8/fs/umsdos/inode.c
--- linux-260-test8-efs/fs/umsdos/inode.c 2003-10-17 14:42:54.000000000 -0700
+++ linux-260-test8/fs/umsdos/inode.c 2003-10-23 23:18:39.000000000 -0700
@@ -11,16 +11,21 @@
#include <linux/fs.h>
#include <linux/msdos_fs.h>
#include <linux/kernel.h>
+#include <linux/namei.h>
#include <linux/time.h>
#include <linux/errno.h>
#include <asm/uaccess.h>
#include <linux/string.h>
#include <linux/stat.h>
+#include <linux/statfs.h>
+#include <linux/smp_lock.h>
#include <linux/umsdos_fs.h>
+#include <linux/umsdos_fs_i.h>
#include <linux/list.h>
#include <linux/pagemap.h>

extern struct dentry_operations umsdos_dentry_operations;
+extern dev_t ROOT_DEV;

struct dentry *saved_root; /* Original root if changed */
struct inode *pseudo_root; /* Useful to simulate the pseudo DOS */
@@ -49,7 +54,9 @@ void UMSDOS_put_inode (struct inode *ino
void UMSDOS_put_super (struct super_block *sb)
{
Printk ((KERN_DEBUG "UMSDOS_put_super: entering\n"));
- if (saved_root && pseudo_root && kdev_same(sb->s_dev, ROOT_DEV)) {
+ if (saved_root && pseudo_root &&
+ old_encode_dev(sb->s_dev) == old_encode_dev(ROOT_DEV)) {
+ /* TBD: is using 16-bit dev_t OK here? */
shrink_dcache_parent(saved_root);
dput(saved_root);
saved_root = NULL;
@@ -150,7 +157,7 @@ dentry, f_pos));
inode->i_op = &umsdos_symlink_inode_operations;
} else
init_special_inode(inode, inode->i_mode,
- kdev_t_to_nr(inode->i_rdev));
+ inode->i_rdev);
}


@@ -282,12 +289,15 @@ dentry->d_parent->d_name.name, dentry->d
entry->gid = cpu_to_le16(attr->ia_gid);
if (attr->ia_valid & ATTR_MODE)
entry->mode = cpu_to_le16(attr->ia_mode);
+ /* TBD: fix times */
+#if 0
if (attr->ia_valid & ATTR_ATIME)
entry->atime = cpu_to_le32(attr->ia_atime);
if (attr->ia_valid & ATTR_MTIME)
entry->mtime = cpu_to_le32(attr->ia_mtime);
if (attr->ia_valid & ATTR_CTIME)
entry->ctime = cpu_to_le32(attr->ia_ctime);
+#endif
entry->nlink = cpu_to_le16(inode->i_nlink);
ret=mapping->a_ops->commit_write(NULL,page,offs,offs+UMSDOS_REC_SIZE);
if (ret)
@@ -343,7 +353,7 @@ static struct super_operations umsdos_so
.clear_inode = fat_clear_inode,
};

-int UMSDOS_statfs(struct super_block *sb,struct statfs *buf)
+int UMSDOS_statfs(struct super_block *sb, struct kstatfs *buf)
{
int ret;
ret = fat_statfs (sb, buf);
@@ -355,26 +365,27 @@ int UMSDOS_statfs(struct super_block *sb
/*
* Read the super block of an Extended MS-DOS FS.
*/
-struct super_block *UMSDOS_read_super (struct super_block *sb, void *data,
- int silent)
+int UMSDOS_read_super (struct super_block *sb,
+ void *data, int silent,
+ struct inode_operations *fs_dir_inode_ops,
+ int isvfat)
{
- struct super_block *res;
struct dentry *new_root;
+ int res;

/*
* Call msdos-fs to mount the disk.
- * Note: this returns res == sb or NULL
+ * Note: this returns res == 0 (success) else error.
*/
MSDOS_SB(sb)->options.isvfat = 0;
- res = fat_read_super(sb, data, silent, &umsdos_rdir_inode_operations);
-
- if (IS_ERR(res))
- return NULL;
- if (res == NULL) {
+ // TBD: which inode_operations to use:
+ res = fat_fill_super(sb, data, silent,
+ &umsdos_rdir_inode_operations, isvfat);
+ if (res) {
if (!silent)
printk(KERN_INFO "VFS: Can't find a valid "
"UMSDOS filesystem on dev %s.\n", sb->s_id);
- return NULL;
+ return res;
}

printk (KERN_INFO "UMSDOS 0.86k "
@@ -402,14 +413,13 @@ struct super_block *UMSDOS_read_super (s
printk(KERN_INFO "UMSDOS: changed to alternate root\n");
dget (sb->s_root); sb->s_root = dget(new_root);
}
- return sb;
+ return 0;
}

/*
* Check for an alternate root if we're the root device.
*/

-extern kdev_t ROOT_DEV;
static struct dentry *check_pseudo_root(struct super_block *sb)
{
struct dentry *root, *sbin, *init;
@@ -419,14 +429,15 @@ static struct dentry *check_pseudo_root(
* must check like this, because we can be used with initrd
*/

- if (!kdev_same(sb->s_dev, ROOT_DEV))
+ if (old_encode_dev(sb->s_dev) != old_encode_dev(ROOT_DEV))
goto out_noroot;

/*
* lookup_dentry needs a (so far non-existent) root.
*/
printk(KERN_INFO "check_pseudo_root: mounted as root\n");
- root = lookup_one_len(UMSDOS_PSDROOT_NAME, sb->s_root,UMSDOS_PSDROOT_LEN);
+ root = lookup_one_len(UMSDOS_PSDROOT_NAME,
+ sb->s_root, UMSDOS_PSDROOT_LEN);
if (IS_ERR(root))
goto out_noroot;

@@ -464,7 +475,31 @@ out_noroot:
}


-static DECLARE_FSTYPE_DEV(umsdos_fs_type, "umsdos", UMSDOS_read_super);
+static int umsdos_fill_super(struct super_block *sb, void *data, int silent)
+{
+ int res;
+
+ res = UMSDOS_read_super(sb, data, silent, &umsdos_dir_inode_operations, 0);
+
+ return res;
+}
+
+static struct super_block *umsdos_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return get_sb_bdev(fs_type, flags, dev_name, data, umsdos_fill_super);
+}
+
+//TBD: must EXPORT all entry points;
+//and use UMSDOS_ for them by local convention;
+
+static struct file_system_type umsdos_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "umsdos",
+ .get_sb = umsdos_get_sb,
+ .kill_sb = kill_block_super,
+ .fs_flags = FS_REQUIRES_DEV,
+};

static int __init init_umsdos_fs (void)
{
diff -Naurp linux-260-test8-efs/fs/umsdos/ioctl.c linux-260-test8/fs/umsdos/ioctl.c
--- linux-260-test8-efs/fs/umsdos/ioctl.c 2003-10-17 14:42:54.000000000 -0700
+++ linux-260-test8/fs/umsdos/ioctl.c 2003-10-23 21:22:53.000000000 -0700
@@ -402,9 +402,10 @@ new_dentry->d_parent->d_name.name, new_d
data.stat.st_ino = inode->i_ino;
data.stat.st_mode = inode->i_mode;
data.stat.st_size = inode->i_size;
- data.stat.st_atime = inode->i_atime;
- data.stat.st_ctime = inode->i_ctime;
- data.stat.st_mtime = inode->i_mtime;
+ /* TBD: fix times */
+ ///data.stat.st_atime = inode->i_atime;
+ ///data.stat.st_ctime = inode->i_ctime;
+ ///data.stat.st_mtime = inode->i_mtime;
ret = -EFAULT;
if (!copy_to_user (&idata->stat, &data.stat,
sizeof (data.stat)))
@@ -414,6 +415,7 @@ new_dentry->d_parent->d_name.name, new_d
goto out;
}
else if (cmd == UMSDOS_DOS_SETUP) {
+ struct msdos_sb_info *msdossbi = (struct msdos_sb_info *)dir->i_sb->s_fs_info;
/* #Specification: ioctl / UMSDOS_DOS_SETUP
* The UMSDOS_DOS_SETUP ioctl allow changing the
* default permission of the MS-DOS filesystem driver
@@ -433,10 +435,11 @@ new_dentry->d_parent->d_name.name, new_d
* umsdos_dirent.uid and gid sets the owner and group.
* umsdos_dirent.mode set the permissions flags.
*/
- dir->i_sb->u.msdos_sb.options.fs_uid = data.umsdos_dirent.uid;
- dir->i_sb->u.msdos_sb.options.fs_gid = data.umsdos_dirent.gid;
- dir->i_sb->u.msdos_sb.options.fs_fmask =
- dir->i_sb->u.msdos_sb.options.fs_dmask =
+ msdossbi->options.fs_uid = data.umsdos_dirent.uid;
+ msdossbi->options.fs_gid = data.umsdos_dirent.gid;
+ msdossbi->options.fs_fmask =
+ data.umsdos_dirent.mode;
+ msdossbi->options.fs_dmask =
data.umsdos_dirent.mode;
ret = 0;
}
diff -Naurp linux-260-test8-efs/fs/umsdos/Makefile linux-260-test8/fs/umsdos/Makefile
--- linux-260-test8-efs/fs/umsdos/Makefile 2003-10-17 14:42:58.000000000 -0700
+++ linux-260-test8/fs/umsdos/Makefile 2003-10-23 13:05:13.000000000 -0700
@@ -2,9 +2,9 @@
# Makefile for the umsdos Unix-like filesystem routines.
#

-obj-$(CONFIG_UMSDOS) += umsdos.o
+obj-$(CONFIG_UMSDOS_FS) += umsdos.o

-umsdos-objs := dir.o inode.o ioctl.o mangle.o namei.o rdir.o emd.o
+umsdos-objs := dir.o inode.o ioctl.o mangle.o namei.o rdir.o emd.o

p:
proto *.c >/usr/include/linux/umsdos_fs.p
diff -Naurp linux-260-test8-efs/fs/umsdos/namei.c linux-260-test8/fs/umsdos/namei.c
--- linux-260-test8-efs/fs/umsdos/namei.c 2003-10-17 14:43:23.000000000 -0700
+++ linux-260-test8/fs/umsdos/namei.c 2003-10-23 21:46:02.000000000 -0700
@@ -16,10 +16,12 @@
#include <linux/time.h>
#include <linux/types.h>
#include <linux/fcntl.h>
+#include <linux/sched.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/msdos_fs.h>
#include <linux/umsdos_fs.h>
+#include <linux/umsdos_fs_i.h>
#include <linux/slab.h>

#define UMSDOS_DIR_LOCK
diff -Naurp linux-260-test8-efs/fs/umsdos/rdir.c linux-260-test8/fs/umsdos/rdir.c
--- linux-260-test8-efs/fs/umsdos/rdir.c 2003-10-17 14:42:56.000000000 -0700
+++ linux-260-test8/fs/umsdos/rdir.c 2003-10-23 20:11:33.000000000 -0700
@@ -14,6 +14,7 @@
#include <linux/stat.h>
#include <linux/limits.h>
#include <linux/umsdos_fs.h>
+#include <linux/umsdos_fs_i.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>

diff -Naurp linux-260-test8-efs/fs/umsdos/dir.c linux-260-test8/fs/umsdos/dir.c
--- linux-260-test8-efs/fs/umsdos/dir.c 2003-10-17 14:43:11.000000000 -0700
+++ linux-260-test8/fs/umsdos/dir.c 2003-10-23 23:45:19.000000000 -0700
@@ -15,6 +15,7 @@
#include <linux/stat.h>
#include <linux/limits.h>
#include <linux/umsdos_fs.h>
+#include <linux/umsdos_fs_i.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/smp_lock.h>
@@ -368,13 +369,16 @@ void umsdos_lookup_patch_new(struct dent
if (UMSDOS_I(inode)->i_patched)
goto out;
UMSDOS_I(inode)->i_patched = 1;
- if (S_ISREG (entry->mode))
- entry->mtime = inode->i_mtime;
+ /* TBD: fix mtime */
+ ///if (S_ISREG (entry->mode))
+ ///entry->mtime = inode->i_mtime;
inode->i_mode = entry->mode;
- inode->i_rdev = to_kdev_t (entry->rdev);
- inode->i_atime = entry->atime;
- inode->i_ctime = entry->ctime;
- inode->i_mtime = entry->mtime;
+ /* TBD: still using 16-bit dev_t; is this a problem? */
+ inode->i_rdev = old_decode_dev (entry->rdev);
+ /* TBD: fix times */
+ ///inode->i_atime = entry->atime;
+ ///inode->i_ctime = entry->ctime;
+ ///inode->i_mtime = entry->mtime;
inode->i_uid = entry->uid;
inode->i_gid = entry->gid;

@@ -593,7 +597,7 @@ struct dentry *umsdos_covered(struct den
dentry = d_alloc(parent, &qstr);
if (dentry) {
/* XXXXXXXXXXXXXXXXXXX Race alert! */
- result = UMSDOS_rlookup(parent->d_inode, dentry);
+ result = UMSDOS_rlookup(parent->d_inode, dentry, NULL);
d_drop(dentry);
if (result)
goto out_fail;
@@ -628,8 +632,8 @@ struct dentry *umsdos_lookup_dentry(stru
dentry = d_alloc(parent, &qstr);
if (dentry) {
result = real ?
- UMSDOS_rlookup(parent->d_inode, dentry) :
- UMSDOS_lookup(parent->d_inode, dentry);
+ UMSDOS_rlookup(parent->d_inode, dentry, NULL) :
+ UMSDOS_lookup(parent->d_inode, dentry, NULL);
if (result)
goto out_fail;
return dentry;
@@ -655,7 +659,8 @@ char * umsdos_d_path(struct dentry *dent
old_root = dget(current->fs->root);
read_unlock(&current->fs->lock);
spin_lock(&dcache_lock);
- path = __d_path(dentry, current->fs->rootmnt, dentry->d_sb->s_root, current->fs->rootmnt, buffer, len); /* FIXME: current->fs->rootmnt */
+ /* FIXME: current->fs->rootmnt: */
+ path = d_path(dentry, current->fs->rootmnt, buffer, len);
spin_unlock(&dcache_lock);

if (*path == '/')

-
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