447 lines
13 KiB
C
447 lines
13 KiB
C
/*
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* linux/fs/umsdos/ioctl.c
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*
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* Written 1993 by Jacques Gelinas
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*
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* Extended MS-DOS ioctl directory handling functions
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*
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* Changes:
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* 11/07/2003 Daniele Bellucci <bellucda@tiscali.it>
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* - audit copy_to_user/put_user in umsdos_ioctl_fill.
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*/
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#include <asm/uaccess.h>
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#include <linux/errno.h>
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#include <linux/mm.h>
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#include <linux/kernel.h>
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#include <linux/time.h>
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#include <linux/fs.h>
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#include <linux/msdos_fs.h>
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#include <linux/umsdos_fs.h>
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struct UMSDOS_DIR_ONCE {
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struct dirent *ent;
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int count;
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};
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/*
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* Record a single entry the first call.
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* Return -EINVAL the next one.
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*/
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static int umsdos_ioctl_fill (
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void *buf,
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const char *name,
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int name_len,
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loff_t offset,
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ino_t ino,
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unsigned type)
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{
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int ret = -EINVAL;
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struct UMSDOS_DIR_ONCE *d = (struct UMSDOS_DIR_ONCE *) buf;
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if (d->count == 0) {
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if (copy_to_user (d->ent->d_name, name, name_len) ||
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put_user ('\0', d->ent->d_name + name_len) ||
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put_user (name_len, &d->ent->d_reclen) ||
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put_user (ino, &d->ent->d_ino) ||
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put_user (offset, &d->ent->d_off))
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return -EFAULT;
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d->count = 1;
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ret = 0;
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}
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return ret;
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}
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/*
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* Perform special function on a directory
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*/
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/* #Specification: ioctl / prototypes
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* The official prototype for the umsdos ioctl on directory
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* is:
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*
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* int ioctl (
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* int fd, // File handle of the directory
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* int cmd, // command
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* struct umsdos_ioctl *data)
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*
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* The struct and the commands are defined in linux/umsdos_fs.h.
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*
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* umsdos_progs/umsdosio.c provide an interface in C++ to all
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* these ioctl. umsdos_progs/udosctl is a small utility showing
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* all this.
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*
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* These ioctl generally allow one to work on the EMD or the
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* DOS directory independently. These are essential to implement
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* the synchronise.
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*/
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int UMSDOS_ioctl_dir(struct inode *dir, struct file *filp, unsigned int cmd,
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unsigned long data_ptr)
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{
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struct dentry *dentry = filp->f_dentry;
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struct umsdos_ioctl *idata = (struct umsdos_ioctl *) data_ptr;
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int ret;
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struct umsdos_ioctl data;
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Printk(("UMSDOS_ioctl_dir: %s/%s, cmd=%d, data=%08lx\n",
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dentry->d_parent->d_name.name, dentry->d_name.name, cmd, data_ptr));
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/* forward non-umsdos ioctls - this hopefully doesn't cause conflicts */
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if (cmd != UMSDOS_GETVERSION
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&& cmd != UMSDOS_READDIR_DOS
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&& cmd != UMSDOS_READDIR_EMD
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&& cmd != UMSDOS_INIT_EMD
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&& cmd != UMSDOS_CREAT_EMD
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&& cmd != UMSDOS_RENAME_DOS
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&& cmd != UMSDOS_UNLINK_EMD
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&& cmd != UMSDOS_UNLINK_DOS
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&& cmd != UMSDOS_RMDIR_DOS
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&& cmd != UMSDOS_STAT_DOS
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&& cmd != UMSDOS_DOS_SETUP)
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return fat_dir_ioctl (dir, filp, cmd, data_ptr);
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/* #Specification: ioctl / access
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* Only root (effective id) is allowed to do IOCTL on directory
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* in UMSDOS. EPERM is returned for other user.
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*/
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/*
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* Well, not all cases require write access, but it simplifies
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* the code, and let's face it, there is only one client (umssync)
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* for all this.
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*/
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ret = verify_area (VERIFY_WRITE, (void *) data_ptr,
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sizeof (struct umsdos_ioctl));
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if (ret < 0)
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goto out;
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ret = -EPERM;
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if (current->euid != 0 && cmd != UMSDOS_GETVERSION)
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goto out;
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ret = -EINVAL;
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if (cmd == UMSDOS_GETVERSION) {
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/* #Specification: ioctl / UMSDOS_GETVERSION
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* The field version and release of the structure
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* umsdos_ioctl are filled with the version and release
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* number of the fs code in the kernel. This will allow
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* some form of checking. Users won't be able to run
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* incompatible utility such as the synchroniser (umssync).
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* umsdos_progs/umsdosio.c enforce this checking.
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*
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* Return always 0.
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*/
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put_user (UMSDOS_VERSION, &idata->version);
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put_user (UMSDOS_RELEASE, &idata->release);
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ret = 0;
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goto out;
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}
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if (cmd == UMSDOS_READDIR_DOS) {
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/* #Specification: ioctl / UMSDOS_READDIR_DOS
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* One entry is read from the DOS directory at the current
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* file position. The entry is put as is in the dos_dirent
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* field of struct umsdos_ioctl.
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*
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* Return > 0 if success.
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*/
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struct UMSDOS_DIR_ONCE bufk;
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bufk.count = 0;
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bufk.ent = &idata->dos_dirent;
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fat_readdir (filp, &bufk, umsdos_ioctl_fill);
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ret = bufk.count == 1 ? 1 : 0;
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goto out;
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}
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if (cmd == UMSDOS_READDIR_EMD) {
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/* #Specification: ioctl / UMSDOS_READDIR_EMD
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* One entry is read from the EMD at the current
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* file position. The entry is put as is in the umsdos_dirent
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* field of struct umsdos_ioctl. The corresponding mangled
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* DOS entry name is put in the dos_dirent field.
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*
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* All entries are read including hidden links. Blank
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* entries are skipped.
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*
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* Return > 0 if success.
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*/
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struct dentry *demd;
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loff_t pos = filp->f_pos;
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/* The absence of the EMD is simply seen as an EOF */
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demd = umsdos_get_emd_dentry(dentry);
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ret = PTR_ERR(demd);
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if (IS_ERR(demd))
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goto out;
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ret = 0;
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if (!demd->d_inode)
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goto read_dput;
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while (pos < demd->d_inode->i_size) {
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off_t f_pos = pos;
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struct umsdos_dirent entry;
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struct umsdos_info info;
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ret = umsdos_emd_dir_readentry (demd, &pos, &entry);
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if (ret == -ENAMETOOLONG) {
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printk (KERN_INFO "Fixing EMD entry with invalid size -- zeroing out\n");
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memset (&info, 0, sizeof (info));
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info.f_pos = f_pos;
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info.recsize = UMSDOS_REC_SIZE;
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ret = umsdos_writeentry (dentry, &info, 1);
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continue;
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}
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if (ret)
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break;
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if (entry.name_len <= 0)
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continue;
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umsdos_parse (entry.name, entry.name_len, &info);
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info.f_pos = f_pos;
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umsdos_manglename (&info);
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ret = -EFAULT;
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if (copy_to_user (&idata->umsdos_dirent, &entry,
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sizeof (entry)))
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break;
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if (copy_to_user (&idata->dos_dirent.d_name,
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info.fake.fname,
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info.fake.len + 1))
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break;
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ret = entry.name_len;
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break;
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}
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/* update the original f_pos */
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filp->f_pos = pos;
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read_dput:
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d_drop(demd);
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dput(demd);
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goto out;
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}
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if (cmd == UMSDOS_INIT_EMD) {
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/* #Specification: ioctl / UMSDOS_INIT_EMD
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* The UMSDOS_INIT_EMD command makes sure the EMD
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* exists for a directory. If it does not, it is
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* created. Also, it makes sure the directory function
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* table (struct inode_operations) is set to the UMSDOS
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* semantic. This mean that umssync may be applied to
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* an "opened" msdos directory, and it will change behavior
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* on the fly.
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*
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* Return 0 if success.
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*/
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ret = umsdos_make_emd(dentry);
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Printk(("UMSDOS_ioctl_dir: INIT_EMD %s/%s, ret=%d\n",
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dentry->d_parent->d_name.name, dentry->d_name.name, ret));
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umsdos_setup_dir (dentry);
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goto out;
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}
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ret = -EFAULT;
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if (copy_from_user (&data, idata, sizeof (data)))
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goto out;
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if (cmd == UMSDOS_CREAT_EMD) {
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/* #Specification: ioctl / UMSDOS_CREAT_EMD
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* The umsdos_dirent field of the struct umsdos_ioctl is used
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* as is to create a new entry in the EMD of the directory.
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* The DOS directory is not modified.
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* No validation is done (yet).
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*
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* Return 0 if success.
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*/
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struct umsdos_info info;
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/* This makes sure info.entry and info in general
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* is correctly initialised
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*/
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memcpy (&info.entry, &data.umsdos_dirent,
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sizeof (data.umsdos_dirent));
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umsdos_parse (data.umsdos_dirent.name
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,data.umsdos_dirent.name_len, &info);
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ret = umsdos_newentry (dentry, &info);
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goto out;
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}
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else if (cmd == UMSDOS_RENAME_DOS) {
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struct dentry *old_dentry, *new_dentry; /* FIXME */
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/* #Specification: ioctl / UMSDOS_RENAME_DOS
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* A file or directory is renamed in a DOS directory
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* (not moved across directory). The source name
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* is in the dos_dirent.name field and the destination
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* is in umsdos_dirent.name field.
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*
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* This ioctl allows umssync to rename a mangled file
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* name before syncing it back in the EMD.
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*/
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old_dentry = umsdos_lookup_dentry (dentry,
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data.dos_dirent.d_name,
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data.dos_dirent.d_reclen ,1);
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ret = PTR_ERR(old_dentry);
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if (IS_ERR(old_dentry))
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goto out;
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new_dentry = umsdos_lookup_dentry (dentry,
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data.umsdos_dirent.name,
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data.umsdos_dirent.name_len, 1);
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ret = PTR_ERR(new_dentry);
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if (!IS_ERR(new_dentry)) {
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printk("umsdos_ioctl: renaming %s/%s to %s/%s\n",
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old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
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new_dentry->d_parent->d_name.name, new_dentry->d_name.name);
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ret = msdos_rename (dir, old_dentry, dir, new_dentry);
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d_drop(new_dentry);
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d_drop(old_dentry);
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dput(new_dentry);
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}
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dput(old_dentry);
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goto out;
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}
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else if (cmd == UMSDOS_UNLINK_EMD) {
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/* #Specification: ioctl / UMSDOS_UNLINK_EMD
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* The umsdos_dirent field of the struct umsdos_ioctl is used
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* as is to remove an entry from the EMD of the directory.
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* No validation is done (yet). The mode field is used
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* to validate S_ISDIR or S_ISREG.
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*
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* Return 0 if success.
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*/
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struct umsdos_info info;
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/* This makes sure info.entry and info in general
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* is correctly initialised
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*/
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memcpy (&info.entry, &data.umsdos_dirent,
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sizeof (data.umsdos_dirent));
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umsdos_parse (data.umsdos_dirent.name,
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data.umsdos_dirent.name_len, &info);
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ret = umsdos_delentry (dentry, &info,
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S_ISDIR (data.umsdos_dirent.mode));
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if (ret) {
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printk(KERN_WARNING
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"umsdos_ioctl: delentry %s/%s failed, ret=%d\n",
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dentry->d_name.name, info.entry.name, ret);
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}
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goto out;
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}
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else if (cmd == UMSDOS_UNLINK_DOS) {
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struct dentry *temp;
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/* #Specification: ioctl / UMSDOS_UNLINK_DOS
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* The dos_dirent field of the struct umsdos_ioctl is used to
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* execute a msdos_unlink operation. The d_name and d_reclen
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* fields are used.
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*
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* Return 0 if success.
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*/
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temp = umsdos_lookup_dentry(dentry, data.dos_dirent.d_name,
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data.dos_dirent.d_reclen, 1);
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ret = PTR_ERR(temp);
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if (IS_ERR(temp))
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goto out;
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ret = -ENOENT;
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if (temp->d_inode) {
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ret = -EISDIR;
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if (!S_ISDIR(temp->d_inode->i_mode))
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ret = msdos_unlink (dir, temp);
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if (!ret)
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d_delete(temp);
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}
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dput (temp);
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goto out;
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}
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else if (cmd == UMSDOS_RMDIR_DOS) {
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struct dentry *temp;
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/* #Specification: ioctl / UMSDOS_RMDIR_DOS
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* The dos_dirent field of the struct umsdos_ioctl is used to
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* execute a msdos_rmdir operation. The d_name and d_reclen
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* fields are used.
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*
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* Return 0 if success.
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*/
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temp = umsdos_lookup_dentry(dentry, data.dos_dirent.d_name,
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data.dos_dirent.d_reclen, 1);
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ret = PTR_ERR(temp);
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if (IS_ERR(temp))
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goto out;
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ret = -ENOENT;
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if (temp->d_inode) {
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ret = -ENOTDIR;
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if (S_ISDIR(temp->d_inode->i_mode))
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ret = msdos_rmdir (dir, temp);
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if (!ret)
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d_delete(temp);
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}
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dput (temp);
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goto out;
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} else if (cmd == UMSDOS_STAT_DOS) {
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/* #Specification: ioctl / UMSDOS_STAT_DOS
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* The dos_dirent field of the struct umsdos_ioctl is
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* used to execute a stat operation in the DOS directory.
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* The d_name and d_reclen fields are used.
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*
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* The following field of umsdos_ioctl.stat are filled.
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*
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* st_ino,st_mode,st_size,st_atime,st_mtime,st_ctime,
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* Return 0 if success.
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*/
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struct dentry *dret;
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struct inode *inode;
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dret = umsdos_lookup_dentry(dentry, data.dos_dirent.d_name,
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data.dos_dirent.d_reclen, 1);
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ret = PTR_ERR(dret);
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if (IS_ERR(dret))
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goto out;
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ret = -ENOENT;
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inode = dret->d_inode;
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if (inode) {
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data.stat.st_ino = inode->i_ino;
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data.stat.st_mode = inode->i_mode;
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data.stat.st_size = inode->i_size;
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data.stat.st_atime = inode->i_atime;
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data.stat.st_ctime = inode->i_ctime;
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data.stat.st_mtime = inode->i_mtime;
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ret = -EFAULT;
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if (!copy_to_user (&idata->stat, &data.stat,
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sizeof (data.stat)))
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ret = 0;
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}
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dput(dret);
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goto out;
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}
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else if (cmd == UMSDOS_DOS_SETUP) {
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/* #Specification: ioctl / UMSDOS_DOS_SETUP
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* The UMSDOS_DOS_SETUP ioctl allow changing the
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* default permission of the MS-DOS filesystem driver
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* on the fly. The MS-DOS driver applies global permissions
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* to every file and directory. Normally these permissions
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* are controlled by a mount option. This is not
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* available for root partition, so a special utility
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* (umssetup) is provided to do this, normally in
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* /etc/rc.local.
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*
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* Be aware that this applies ONLY to MS-DOS directories
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* (those without EMD --linux-.---). Umsdos directory
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* have independent (standard) permission for each
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* and every file.
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*
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* The field umsdos_dirent provide the information needed.
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* umsdos_dirent.uid and gid sets the owner and group.
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* umsdos_dirent.mode set the permissions flags.
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*/
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dir->i_sb->u.msdos_sb.options.fs_uid = data.umsdos_dirent.uid;
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dir->i_sb->u.msdos_sb.options.fs_gid = data.umsdos_dirent.gid;
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dir->i_sb->u.msdos_sb.options.fs_fmask =
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dir->i_sb->u.msdos_sb.options.fs_dmask =
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data.umsdos_dirent.mode;
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ret = 0;
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}
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out:
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Printk (("ioctl %d, returning %d\n", cmd, ret));
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return ret;
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}
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