aboutsummaryrefslogtreecommitdiff
path: root/fs/ntfs
diff options
context:
space:
mode:
authorAnton Altaparmakov2006-01-19 16:39:33 +0000
committerAnton Altaparmakov2006-01-19 16:39:33 +0000
commit944d79559d154c12becde0dab327016cf438f46c (patch)
tree50c101806f4d3b6585222dda060559eb4f3e005a /fs/ntfs
parentd087e4bdd24ebe3ae3d0b265b6573ec901af4b4b (diff)
parent0f36b018b2e314d45af86449f1a97facb1fbe300 (diff)
Merge branch 'master' of /usr/src/ntfs-2.6/
Diffstat (limited to 'fs/ntfs')
-rw-r--r--fs/ntfs/ChangeLog2
-rw-r--r--fs/ntfs/attrib.c4
-rw-r--r--fs/ntfs/dir.c8
-rw-r--r--fs/ntfs/file.c20
-rw-r--r--fs/ntfs/index.c6
-rw-r--r--fs/ntfs/inode.c28
-rw-r--r--fs/ntfs/namei.c6
-rw-r--r--fs/ntfs/quota.c6
-rw-r--r--fs/ntfs/super.c44
9 files changed, 71 insertions, 53 deletions
diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
index 50a7749cfca1..02f44094bda9 100644
--- a/fs/ntfs/ChangeLog
+++ b/fs/ntfs/ChangeLog
@@ -884,7 +884,7 @@ ToDo/Notes:
- Add handling for initialized_size != data_size in compressed files.
- Reduce function local stack usage from 0x3d4 bytes to just noise in
- fs/ntfs/upcase.c. (Randy Dunlap <rddunlap@osdl.ord>)
+ fs/ntfs/upcase.c. (Randy Dunlap <rdunlap@xenotime.net>)
- Remove compiler warnings for newer gcc.
- Pages are no longer kmapped by mm/filemap.c::generic_file_write()
around calls to ->{prepare,commit}_write. Adapt NTFS appropriately
diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index eda056bac256..9480a0526cd3 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -1532,7 +1532,7 @@ int ntfs_resident_attr_value_resize(MFT_RECORD *m, ATTR_RECORD *a,
* NOTE to self: No changes in the attribute list are required to move from
* a resident to a non-resident attribute.
*
- * Locking: - The caller must hold i_sem on the inode.
+ * Locking: - The caller must hold i_mutex on the inode.
*/
int ntfs_attr_make_non_resident(ntfs_inode *ni, const u32 data_size)
{
@@ -1728,7 +1728,7 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni, const u32 data_size)
/*
* This needs to be last since the address space operations ->readpage
* and ->writepage can run concurrently with us as they are not
- * serialized on i_sem. Note, we are not allowed to fail once we flip
+ * serialized on i_mutex. Note, we are not allowed to fail once we flip
* this switch, which is another reason to do this last.
*/
NInoSetNonResident(ni);
diff --git a/fs/ntfs/dir.c b/fs/ntfs/dir.c
index 795c3d1930f5..b0690d4c8906 100644
--- a/fs/ntfs/dir.c
+++ b/fs/ntfs/dir.c
@@ -69,7 +69,7 @@ ntfschar I30[5] = { const_cpu_to_le16('$'), const_cpu_to_le16('I'),
* work but we don't care for how quickly one can access them. This also fixes
* the dcache aliasing issues.
*
- * Locking: - Caller must hold i_sem on the directory.
+ * Locking: - Caller must hold i_mutex on the directory.
* - Each page cache page in the index allocation mapping must be
* locked whilst being accessed otherwise we may find a corrupt
* page due to it being under ->writepage at the moment which
@@ -1085,11 +1085,11 @@ static inline int ntfs_filldir(ntfs_volume *vol, loff_t fpos,
* While this will return the names in random order this doesn't matter for
* ->readdir but OTOH results in a faster ->readdir.
*
- * VFS calls ->readdir without BKL but with i_sem held. This protects the VFS
+ * VFS calls ->readdir without BKL but with i_mutex held. This protects the VFS
* parts (e.g. ->f_pos and ->i_size, and it also protects against directory
* modifications).
*
- * Locking: - Caller must hold i_sem on the directory.
+ * Locking: - Caller must hold i_mutex on the directory.
* - Each page cache page in the index allocation mapping must be
* locked whilst being accessed otherwise we may find a corrupt
* page due to it being under ->writepage at the moment which
@@ -1520,7 +1520,7 @@ static int ntfs_dir_open(struct inode *vi, struct file *filp)
* Note: In the past @filp could be NULL so we ignore it as we don't need it
* anyway.
*
- * Locking: Caller must hold i_sem on the inode.
+ * Locking: Caller must hold i_mutex on the inode.
*
* TODO: We should probably also write all attribute/index inodes associated
* with this inode but since we have no simple way of getting to them we ignore
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index c73c8864cbad..3a119a87686a 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -106,7 +106,7 @@ static int ntfs_file_open(struct inode *vi, struct file *filp)
* this is the case, the necessary zeroing will also have happened and that all
* metadata is self-consistent.
*
- * Locking: i_sem on the vfs inode corrseponsind to the ntfs inode @ni must be
+ * Locking: i_mutex on the vfs inode corrseponsind to the ntfs inode @ni must be
* held by the caller.
*/
static int ntfs_attr_extend_initialized(ntfs_inode *ni, const s64 new_init_size,
@@ -473,7 +473,7 @@ static inline int ntfs_submit_bh_for_read(struct buffer_head *bh)
* @bytes: number of bytes to be written
*
* This is called for non-resident attributes from ntfs_file_buffered_write()
- * with i_sem held on the inode (@pages[0]->mapping->host). There are
+ * with i_mutex held on the inode (@pages[0]->mapping->host). There are
* @nr_pages pages in @pages which are locked but not kmap()ped. The source
* data has not yet been copied into the @pages.
*
@@ -1637,7 +1637,7 @@ err_out:
* @pos: byte position in file at which the write begins
* @bytes: number of bytes to be written
*
- * This is called from ntfs_file_buffered_write() with i_sem held on the inode
+ * This is called from ntfs_file_buffered_write() with i_mutex held on the inode
* (@pages[0]->mapping->host). There are @nr_pages pages in @pages which are
* locked but not kmap()ped. The source data has already been copied into the
* @page. ntfs_prepare_pages_for_non_resident_write() has been called before
@@ -1814,7 +1814,7 @@ err_out:
/**
* ntfs_file_buffered_write -
*
- * Locking: The vfs is holding ->i_sem on the inode.
+ * Locking: The vfs is holding ->i_mutex on the inode.
*/
static ssize_t ntfs_file_buffered_write(struct kiocb *iocb,
const struct iovec *iov, unsigned long nr_segs,
@@ -2173,7 +2173,7 @@ static ssize_t ntfs_file_aio_write_nolock(struct kiocb *iocb,
err = remove_suid(file->f_dentry);
if (err)
goto out;
- inode_update_time(inode, 1);
+ file_update_time(file);
written = ntfs_file_buffered_write(iocb, iov, nr_segs, pos, ppos,
count);
out:
@@ -2196,9 +2196,9 @@ static ssize_t ntfs_file_aio_write(struct kiocb *iocb, const char __user *buf,
BUG_ON(iocb->ki_pos != pos);
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
ret = ntfs_file_aio_write_nolock(iocb, &local_iov, 1, &iocb->ki_pos);
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
int err = sync_page_range(inode, mapping, pos, ret);
if (err < 0)
@@ -2221,12 +2221,12 @@ static ssize_t ntfs_file_writev(struct file *file, const struct iovec *iov,
struct kiocb kiocb;
ssize_t ret;
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
init_sync_kiocb(&kiocb, file);
ret = ntfs_file_aio_write_nolock(&kiocb, iov, nr_segs, ppos);
if (ret == -EIOCBQUEUED)
ret = wait_on_sync_kiocb(&kiocb);
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
int err = sync_page_range(inode, mapping, *ppos - ret, ret);
if (err < 0)
@@ -2269,7 +2269,7 @@ static ssize_t ntfs_file_write(struct file *file, const char __user *buf,
* Note: In the past @filp could be NULL so we ignore it as we don't need it
* anyway.
*
- * Locking: Caller must hold i_sem on the inode.
+ * Locking: Caller must hold i_mutex on the inode.
*
* TODO: We should probably also write all attribute/index inodes associated
* with this inode but since we have no simple way of getting to them we ignore
diff --git a/fs/ntfs/index.c b/fs/ntfs/index.c
index 8f2d5727546f..9f5427c2d105 100644
--- a/fs/ntfs/index.c
+++ b/fs/ntfs/index.c
@@ -32,7 +32,7 @@
* Allocate a new index context, initialize it with @idx_ni and return it.
* Return NULL if allocation failed.
*
- * Locking: Caller must hold i_sem on the index inode.
+ * Locking: Caller must hold i_mutex on the index inode.
*/
ntfs_index_context *ntfs_index_ctx_get(ntfs_inode *idx_ni)
{
@@ -50,7 +50,7 @@ ntfs_index_context *ntfs_index_ctx_get(ntfs_inode *idx_ni)
*
* Release the index context @ictx, releasing all associated resources.
*
- * Locking: Caller must hold i_sem on the index inode.
+ * Locking: Caller must hold i_mutex on the index inode.
*/
void ntfs_index_ctx_put(ntfs_index_context *ictx)
{
@@ -106,7 +106,7 @@ void ntfs_index_ctx_put(ntfs_index_context *ictx)
* or ntfs_index_entry_write() before the call to ntfs_index_ctx_put() to
* ensure that the changes are written to disk.
*
- * Locking: - Caller must hold i_sem on the index inode.
+ * Locking: - Caller must hold i_mutex on the index inode.
* - Each page cache page in the index allocation mapping must be
* locked whilst being accessed otherwise we may find a corrupt
* page due to it being under ->writepage at the moment which
diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index b24f4c4b2c5c..ea1bd3feea1b 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -2125,13 +2125,13 @@ void ntfs_put_inode(struct inode *vi)
ntfs_inode *ni = NTFS_I(vi);
if (NInoIndexAllocPresent(ni)) {
struct inode *bvi = NULL;
- down(&vi->i_sem);
+ mutex_lock(&vi->i_mutex);
if (atomic_read(&vi->i_count) == 2) {
bvi = ni->itype.index.bmp_ino;
if (bvi)
ni->itype.index.bmp_ino = NULL;
}
- up(&vi->i_sem);
+ mutex_unlock(&vi->i_mutex);
if (bvi)
iput(bvi);
}
@@ -2311,7 +2311,7 @@ static const char *es = " Leaving inconsistent metadata. Unmount and run "
*
* Returns 0 on success or -errno on error.
*
- * Called with ->i_sem held. In all but one case ->i_alloc_sem is held for
+ * Called with ->i_mutex held. In all but one case ->i_alloc_sem is held for
* writing. The only case in the kernel where ->i_alloc_sem is not held is
* mm/filemap.c::generic_file_buffered_write() where vmtruncate() is called
* with the current i_size as the offset. The analogous place in NTFS is in
@@ -2767,7 +2767,25 @@ unm_done:
up_write(&ni->runlist.lock);
done:
/* Update the mtime and ctime on the base inode. */
- inode_update_time(VFS_I(base_ni), 1);
+ /* normally ->truncate shouldn't update ctime or mtime,
+ * but ntfs did before so it got a copy & paste version
+ * of file_update_time. one day someone should fix this
+ * for real.
+ */
+ if (!IS_NOCMTIME(VFS_I(base_ni)) && !IS_RDONLY(VFS_I(base_ni))) {
+ struct timespec now = current_fs_time(VFS_I(base_ni)->i_sb);
+ int sync_it = 0;
+
+ if (!timespec_equal(&VFS_I(base_ni)->i_mtime, &now) ||
+ !timespec_equal(&VFS_I(base_ni)->i_ctime, &now))
+ sync_it = 1;
+ VFS_I(base_ni)->i_mtime = now;
+ VFS_I(base_ni)->i_ctime = now;
+
+ if (sync_it)
+ mark_inode_dirty_sync(VFS_I(base_ni));
+ }
+
if (likely(!err)) {
NInoClearTruncateFailed(ni);
ntfs_debug("Done.");
@@ -2831,7 +2849,7 @@ void ntfs_truncate_vfs(struct inode *vi) {
* We also abort all changes of user, group, and mode as we do not implement
* the NTFS ACLs yet.
*
- * Called with ->i_sem held. For the ATTR_SIZE (i.e. ->truncate) case, also
+ * Called with ->i_mutex held. For the ATTR_SIZE (i.e. ->truncate) case, also
* called with ->i_alloc_sem held for writing.
*
* Basically this is a copy of generic notify_change() and inode_setattr()
diff --git a/fs/ntfs/namei.c b/fs/ntfs/namei.c
index 351dbc3b6e40..5ea9eb93af62 100644
--- a/fs/ntfs/namei.c
+++ b/fs/ntfs/namei.c
@@ -96,7 +96,7 @@
* name. We then convert the name to the current NLS code page, and proceed
* searching for a dentry with this name, etc, as in case 2), above.
*
- * Locking: Caller must hold i_sem on the directory.
+ * Locking: Caller must hold i_mutex on the directory.
*/
static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent,
struct nameidata *nd)
@@ -254,7 +254,7 @@ handle_name:
nls_name.hash = full_name_hash(nls_name.name, nls_name.len);
/*
- * Note: No need for dent->d_lock lock as i_sem is held on the
+ * Note: No need for dent->d_lock lock as i_mutex is held on the
* parent inode.
*/
@@ -374,7 +374,7 @@ struct inode_operations ntfs_dir_inode_ops = {
* The code is based on the ext3 ->get_parent() implementation found in
* fs/ext3/namei.c::ext3_get_parent().
*
- * Note: ntfs_get_parent() is called with @child_dent->d_inode->i_sem down.
+ * Note: ntfs_get_parent() is called with @child_dent->d_inode->i_mutex down.
*
* Return the dentry of the parent directory on success or the error code on
* error (IS_ERR() is true).
diff --git a/fs/ntfs/quota.c b/fs/ntfs/quota.c
index 833df2a4e9fb..d0ef4182147b 100644
--- a/fs/ntfs/quota.c
+++ b/fs/ntfs/quota.c
@@ -48,7 +48,7 @@ BOOL ntfs_mark_quotas_out_of_date(ntfs_volume *vol)
ntfs_error(vol->sb, "Quota inodes are not open.");
return FALSE;
}
- down(&vol->quota_q_ino->i_sem);
+ mutex_lock(&vol->quota_q_ino->i_mutex);
ictx = ntfs_index_ctx_get(NTFS_I(vol->quota_q_ino));
if (!ictx) {
ntfs_error(vol->sb, "Failed to get index context.");
@@ -98,7 +98,7 @@ BOOL ntfs_mark_quotas_out_of_date(ntfs_volume *vol)
ntfs_index_entry_mark_dirty(ictx);
set_done:
ntfs_index_ctx_put(ictx);
- up(&vol->quota_q_ino->i_sem);
+ mutex_unlock(&vol->quota_q_ino->i_mutex);
/*
* We set the flag so we do not try to mark the quotas out of date
* again on remount.
@@ -110,7 +110,7 @@ done:
err_out:
if (ictx)
ntfs_index_ctx_put(ictx);
- up(&vol->quota_q_ino->i_sem);
+ mutex_unlock(&vol->quota_q_ino->i_mutex);
return FALSE;
}
diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
index 6c16db9e1a8a..c3a3f1a8310b 100644
--- a/fs/ntfs/super.c
+++ b/fs/ntfs/super.c
@@ -443,8 +443,8 @@ static int ntfs_remount(struct super_block *sb, int *flags, char *opt)
ntfs_debug("Entering with remount options string: %s", opt);
#ifndef NTFS_RW
- /* For read-only compiled driver, enforce all read-only flags. */
- *flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ /* For read-only compiled driver, enforce read-only flag. */
+ *flags |= MS_RDONLY;
#else /* NTFS_RW */
/*
* For the read-write compiled driver, if we are remounting read-write,
@@ -1213,10 +1213,10 @@ static int check_windows_hibernation_status(ntfs_volume *vol)
* Find the inode number for the hibernation file by looking up the
* filename hiberfil.sys in the root directory.
*/
- down(&vol->root_ino->i_sem);
+ mutex_lock(&vol->root_ino->i_mutex);
mref = ntfs_lookup_inode_by_name(NTFS_I(vol->root_ino), hiberfil, 12,
&name);
- up(&vol->root_ino->i_sem);
+ mutex_unlock(&vol->root_ino->i_mutex);
if (IS_ERR_MREF(mref)) {
ret = MREF_ERR(mref);
/* If the file does not exist, Windows is not hibernated. */
@@ -1307,10 +1307,10 @@ static BOOL load_and_init_quota(ntfs_volume *vol)
* Find the inode number for the quota file by looking up the filename
* $Quota in the extended system files directory $Extend.
*/
- down(&vol->extend_ino->i_sem);
+ mutex_lock(&vol->extend_ino->i_mutex);
mref = ntfs_lookup_inode_by_name(NTFS_I(vol->extend_ino), Quota, 6,
&name);
- up(&vol->extend_ino->i_sem);
+ mutex_unlock(&vol->extend_ino->i_mutex);
if (IS_ERR_MREF(mref)) {
/*
* If the file does not exist, quotas are disabled and have
@@ -1390,10 +1390,10 @@ static BOOL load_and_init_usnjrnl(ntfs_volume *vol)
* Find the inode number for the transaction log file by looking up the
* filename $UsnJrnl in the extended system files directory $Extend.
*/
- down(&vol->extend_ino->i_sem);
+ mutex_lock(&vol->extend_ino->i_mutex);
mref = ntfs_lookup_inode_by_name(NTFS_I(vol->extend_ino), UsnJrnl, 8,
&name);
- up(&vol->extend_ino->i_sem);
+ mutex_unlock(&vol->extend_ino->i_mutex);
if (IS_ERR_MREF(mref)) {
/*
* If the file does not exist, transaction logging is disabled,
@@ -1721,7 +1721,7 @@ static BOOL load_system_files(ntfs_volume *vol)
es3);
goto iput_mirr_err_out;
}
- sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ sb->s_flags |= MS_RDONLY;
ntfs_error(sb, "%s. Mounting read-only%s",
!vol->mftmirr_ino ? es1 : es2, es3);
} else
@@ -1837,7 +1837,7 @@ get_ctx_vol_failed:
es1, es2);
goto iput_vol_err_out;
}
- sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ sb->s_flags |= MS_RDONLY;
ntfs_error(sb, "%s. Mounting read-only%s", es1, es2);
} else
ntfs_warning(sb, "%s. Will not be able to remount "
@@ -1874,7 +1874,7 @@ get_ctx_vol_failed:
}
goto iput_logfile_err_out;
}
- sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ sb->s_flags |= MS_RDONLY;
ntfs_error(sb, "%s. Mounting read-only%s", es1, es2);
} else
ntfs_warning(sb, "%s. Will not be able to remount "
@@ -1919,7 +1919,7 @@ get_ctx_vol_failed:
es1, es2);
goto iput_root_err_out;
}
- sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ sb->s_flags |= MS_RDONLY;
ntfs_error(sb, "%s. Mounting read-only%s", es1, es2);
} else
ntfs_warning(sb, "%s. Will not be able to remount "
@@ -1943,7 +1943,7 @@ get_ctx_vol_failed:
goto iput_root_err_out;
}
ntfs_error(sb, "%s. Mounting read-only%s", es1, es2);
- sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ sb->s_flags |= MS_RDONLY;
/*
* Do not set NVolErrors() because ntfs_remount() might manage
* to set the dirty flag in which case all would be well.
@@ -1970,7 +1970,7 @@ get_ctx_vol_failed:
goto iput_root_err_out;
}
ntfs_error(sb, "%s. Mounting read-only%s", es1, es2);
- sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ sb->s_flags |= MS_RDONLY;
NVolSetErrors(vol);
}
#endif
@@ -1989,7 +1989,7 @@ get_ctx_vol_failed:
goto iput_root_err_out;
}
ntfs_error(sb, "%s. Mounting read-only%s", es1, es2);
- sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ sb->s_flags |= MS_RDONLY;
NVolSetErrors(vol);
}
#endif /* NTFS_RW */
@@ -2030,7 +2030,7 @@ get_ctx_vol_failed:
es1, es2);
goto iput_quota_err_out;
}
- sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ sb->s_flags |= MS_RDONLY;
ntfs_error(sb, "%s. Mounting read-only%s", es1, es2);
} else
ntfs_warning(sb, "%s. Will not be able to remount "
@@ -2053,7 +2053,7 @@ get_ctx_vol_failed:
goto iput_quota_err_out;
}
ntfs_error(sb, "%s. Mounting read-only%s", es1, es2);
- sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ sb->s_flags |= MS_RDONLY;
NVolSetErrors(vol);
}
/*
@@ -2074,7 +2074,7 @@ get_ctx_vol_failed:
es1, es2);
goto iput_usnjrnl_err_out;
}
- sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ sb->s_flags |= MS_RDONLY;
ntfs_error(sb, "%s. Mounting read-only%s", es1, es2);
} else
ntfs_warning(sb, "%s. Will not be able to remount "
@@ -2097,7 +2097,7 @@ get_ctx_vol_failed:
goto iput_usnjrnl_err_out;
}
ntfs_error(sb, "%s. Mounting read-only%s", es1, es2);
- sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ sb->s_flags |= MS_RDONLY;
NVolSetErrors(vol);
}
#endif /* NTFS_RW */
@@ -2312,9 +2312,9 @@ static void ntfs_put_super(struct super_block *sb)
if (!list_empty(&sb->s_dirty)) {
const char *s1, *s2;
- down(&vol->mft_ino->i_sem);
+ mutex_lock(&vol->mft_ino->i_mutex);
truncate_inode_pages(vol->mft_ino->i_mapping, 0);
- up(&vol->mft_ino->i_sem);
+ mutex_unlock(&vol->mft_ino->i_mutex);
write_inode_now(vol->mft_ino, 1);
if (!list_empty(&sb->s_dirty)) {
static const char *_s1 = "inodes";
@@ -2689,7 +2689,7 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent)
ntfs_debug("Entering.");
#ifndef NTFS_RW
- sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+ sb->s_flags |= MS_RDONLY;
#endif /* ! NTFS_RW */
/* Allocate a new ntfs_volume and place it in sb->s_fs_info. */
sb->s_fs_info = kmalloc(sizeof(ntfs_volume), GFP_NOFS);