Commit 218357ff authored by Anton Altaparmakov's avatar Anton Altaparmakov
Browse files

NTFS: - Use i_size_read() in fs/ntfs/super.c once and then use the cached 


	value afterwards.  Cache the initialized_size in the same way and
	protect access to the two sizes using the size_lock.
      - Minor optimization to fs/ntfs/super.c::ntfs_statfs() and its helpers.

Signed-off-by: default avatarAnton Altaparmakov <aia21@cantab.net>
parent 206f9f35

fs/ntfs/ChangeLog

+4 −0
Original line number Diff line number Diff line
@@ -43,6 +43,10 @@ ToDo/Notes: 
	  same way and protect access to the two sizes using the size_lock.

	- Use i_size_read() in fs/ntfs/dir.c once and then use the cached

	  value afterwards.

	- Use i_size_read() in fs/ntfs/super.c once and then use the cached

	  value afterwards.  Cache the initialized_size in the same way and

	  protect access to the two sizes using the size_lock.

	- Minor optimization to fs/ntfs/super.c::ntfs_statfs() and its helpers.



2.1.22 - Many bug and race fixes and error handling improvements.

fs/ntfs/super.c

+54 −48
Original line number Diff line number Diff line
@@ -990,12 +990,12 @@ static BOOL load_and_init_mft_mirror(ntfs_volume *vol) 
 */

static BOOL check_mft_mirror(ntfs_volume *vol)

{

	unsigned long index;

	struct super_block *sb = vol->sb;

	ntfs_inode *mirr_ni;

	struct page *mft_page, *mirr_page;

	u8 *kmft, *kmirr;

	runlist_element *rl, rl2[2];

	pgoff_t index;

	int mrecs_per_page, i;



	ntfs_debug("Entering.");
@@ -1205,10 +1205,11 @@ static BOOL load_and_init_quota(ntfs_volume *vol) 
 */

static BOOL load_and_init_attrdef(ntfs_volume *vol)

{

	loff_t i_size;

	struct super_block *sb = vol->sb;

	struct inode *ino;

	struct page *page;

	unsigned long index, max_index;

	pgoff_t index, max_index;

	unsigned int size;



	ntfs_debug("Entering.");
@@ -1220,13 +1221,14 @@ static BOOL load_and_init_attrdef(ntfs_volume *vol) 
		goto failed;

	}

	/* The size of FILE_AttrDef must be above 0 and fit inside 31 bits. */

	if (!ino->i_size || ino->i_size > 0x7fffffff)

	i_size = i_size_read(ino);

	if (i_size <= 0 || i_size > 0x7fffffff)

		goto iput_failed;

	vol->attrdef = (ATTR_DEF*)ntfs_malloc_nofs(ino->i_size);

	vol->attrdef = (ATTR_DEF*)ntfs_malloc_nofs(i_size);

	if (!vol->attrdef)

		goto iput_failed;

	index = 0;

	max_index = ino->i_size >> PAGE_CACHE_SHIFT;

	max_index = i_size >> PAGE_CACHE_SHIFT;

	size = PAGE_CACHE_SIZE;

	while (index < max_index) {

		/* Read the attrdef table and copy it into the linear buffer. */
@@ -1239,12 +1241,12 @@ static BOOL load_and_init_attrdef(ntfs_volume *vol) 
		ntfs_unmap_page(page);

	};

	if (size == PAGE_CACHE_SIZE) {

		size = ino->i_size & ~PAGE_CACHE_MASK;

		size = i_size & ~PAGE_CACHE_MASK;

		if (size)

			goto read_partial_attrdef_page;

	}

	vol->attrdef_size = ino->i_size;

	ntfs_debug("Read %llu bytes from $AttrDef.", ino->i_size);

	vol->attrdef_size = i_size;

	ntfs_debug("Read %llu bytes from $AttrDef.", i_size);

	iput(ino);

	return TRUE;

free_iput_failed:
@@ -1267,10 +1269,11 @@ static BOOL load_and_init_attrdef(ntfs_volume *vol) 
 */

static BOOL load_and_init_upcase(ntfs_volume *vol)

{

	loff_t i_size;

	struct super_block *sb = vol->sb;

	struct inode *ino;

	struct page *page;

	unsigned long index, max_index;

	pgoff_t index, max_index;

	unsigned int size;

	int i, max;
@@ -1286,14 +1289,15 @@ static BOOL load_and_init_upcase(ntfs_volume *vol) 
	 * The upcase size must not be above 64k Unicode characters, must not

	 * be zero and must be a multiple of sizeof(ntfschar).

	 */

	if (!ino->i_size || ino->i_size & (sizeof(ntfschar) - 1) ||

			ino->i_size > 64ULL * 1024 * sizeof(ntfschar))

	i_size = i_size_read(ino);

	if (!i_size || i_size & (sizeof(ntfschar) - 1) ||

			i_size > 64ULL * 1024 * sizeof(ntfschar))

		goto iput_upcase_failed;

	vol->upcase = (ntfschar*)ntfs_malloc_nofs(ino->i_size);

	vol->upcase = (ntfschar*)ntfs_malloc_nofs(i_size);

	if (!vol->upcase)

		goto iput_upcase_failed;

	index = 0;

	max_index = ino->i_size >> PAGE_CACHE_SHIFT;

	max_index = i_size >> PAGE_CACHE_SHIFT;

	size = PAGE_CACHE_SIZE;

	while (index < max_index) {

		/* Read the upcase table and copy it into the linear buffer. */
@@ -1306,13 +1310,13 @@ static BOOL load_and_init_upcase(ntfs_volume *vol) 
		ntfs_unmap_page(page);

	};

	if (size == PAGE_CACHE_SIZE) {

		size = ino->i_size & ~PAGE_CACHE_MASK;

		size = i_size & ~PAGE_CACHE_MASK;

		if (size)

			goto read_partial_upcase_page;

	}

	vol->upcase_len = ino->i_size >> UCHAR_T_SIZE_BITS;

	vol->upcase_len = i_size >> UCHAR_T_SIZE_BITS;

	ntfs_debug("Read %llu bytes from $UpCase (expected %zu bytes).",

			ino->i_size, 64 * 1024 * sizeof(ntfschar));

			i_size, 64 * 1024 * sizeof(ntfschar));

	iput(ino);

	down(&ntfs_lock);

	if (!default_upcase) {
@@ -1435,7 +1439,7 @@ static BOOL load_system_files(ntfs_volume *vol) 
			iput(vol->lcnbmp_ino);

		goto bitmap_failed;

	}

	if ((vol->nr_clusters + 7) >> 3 > vol->lcnbmp_ino->i_size) {

	if ((vol->nr_clusters + 7) >> 3 > i_size_read(vol->lcnbmp_ino)) {

		iput(vol->lcnbmp_ino);

bitmap_failed:

		ntfs_error(sb, "Failed to load $Bitmap.");
@@ -1959,8 +1963,7 @@ static s64 get_nr_free_clusters(ntfs_volume *vol) 
	struct address_space *mapping = vol->lcnbmp_ino->i_mapping;

	filler_t *readpage = (filler_t*)mapping->a_ops->readpage;

	struct page *page;

	unsigned long index, max_index;

	unsigned int max_size;

	pgoff_t index, max_index;



	ntfs_debug("Entering.");

	/* Serialize accesses to the cluster bitmap. */
@@ -1972,11 +1975,10 @@ static s64 get_nr_free_clusters(ntfs_volume *vol) 
	 */

	max_index = (((vol->nr_clusters + 7) >> 3) + PAGE_CACHE_SIZE - 1) >>

			PAGE_CACHE_SHIFT;

	/* Use multiples of 4 bytes. */

	max_size = PAGE_CACHE_SIZE >> 2;

	ntfs_debug("Reading $Bitmap, max_index = 0x%lx, max_size = 0x%x.",

			max_index, max_size);

	for (index = 0UL; index < max_index; index++) {

	/* Use multiples of 4 bytes, thus max_size is PAGE_CACHE_SIZE / 4. */

	ntfs_debug("Reading $Bitmap, max_index = 0x%lx, max_size = 0x%lx.",

			max_index, PAGE_CACHE_SIZE / 4);

	for (index = 0; index < max_index; index++) {

		unsigned int i;

		/*

		 * Read the page from page cache, getting it from backing store
@@ -2008,7 +2010,7 @@ static s64 get_nr_free_clusters(ntfs_volume *vol) 
		 * the result as all out of range bytes are set to zero by

		 * ntfs_readpage().

		 */

	  	for (i = 0; i < max_size; i++)

	  	for (i = 0; i < PAGE_CACHE_SIZE / 4; i++)

			nr_free -= (s64)hweight32(kaddr[i]);

		kunmap_atomic(kaddr, KM_USER0);

		page_cache_release(page);
@@ -2031,6 +2033,8 @@ static s64 get_nr_free_clusters(ntfs_volume *vol) 
/**

 * __get_nr_free_mft_records - return the number of free inodes on a volume

 * @vol:	ntfs volume for which to obtain free inode count

 * @nr_free:	number of mft records in file system

 * @max_index:	maximum number of pages containing set bits

 *

 * Calculate the number of free mft records (inodes) on the mounted NTFS

 * volume @vol. We actually calculate the number of mft records in use instead
@@ -2043,32 +2047,20 @@ static s64 get_nr_free_clusters(ntfs_volume *vol) 
 *

 * NOTE: Caller must hold mftbmp_lock rw_semaphore for reading or writing.

 */

static unsigned long __get_nr_free_mft_records(ntfs_volume *vol)

static unsigned long __get_nr_free_mft_records(ntfs_volume *vol,

		s64 nr_free, const pgoff_t max_index)

{

	s64 nr_free;

	u32 *kaddr;

	struct address_space *mapping = vol->mftbmp_ino->i_mapping;

	filler_t *readpage = (filler_t*)mapping->a_ops->readpage;

	struct page *page;

	unsigned long index, max_index;

	unsigned int max_size;

	pgoff_t index;



	ntfs_debug("Entering.");

	/* Number of mft records in file system (at this point in time). */

	nr_free = vol->mft_ino->i_size >> vol->mft_record_size_bits;

	/*

	 * Convert the maximum number of set bits into bytes rounded up, then

	 * convert into multiples of PAGE_CACHE_SIZE, rounding up so that if we

	 * have one full and one partial page max_index = 2.

	 */

	max_index = ((((NTFS_I(vol->mft_ino)->initialized_size >>

			vol->mft_record_size_bits) + 7) >> 3) +

			PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;

	/* Use multiples of 4 bytes. */

	max_size = PAGE_CACHE_SIZE >> 2;

	/* Use multiples of 4 bytes, thus max_size is PAGE_CACHE_SIZE / 4. */

	ntfs_debug("Reading $MFT/$BITMAP, max_index = 0x%lx, max_size = "

			"0x%x.", max_index, max_size);

	for (index = 0UL; index < max_index; index++) {

			"0x%lx.", max_index, PAGE_CACHE_SIZE / 4);

	for (index = 0; index < max_index; index++) {

		unsigned int i;

		/*

		 * Read the page from page cache, getting it from backing store
@@ -2100,7 +2092,7 @@ static unsigned long __get_nr_free_mft_records(ntfs_volume *vol) 
		 * the result as all out of range bytes are set to zero by

		 * ntfs_readpage().

		 */

	  	for (i = 0; i < max_size; i++)

	  	for (i = 0; i < PAGE_CACHE_SIZE / 4; i++)

			nr_free -= (s64)hweight32(kaddr[i]);

		kunmap_atomic(kaddr, KM_USER0);

		page_cache_release(page);
@@ -2134,8 +2126,11 @@ static unsigned long __get_nr_free_mft_records(ntfs_volume *vol) 
 */

static int ntfs_statfs(struct super_block *sb, struct kstatfs *sfs)

{

	ntfs_volume *vol = NTFS_SB(sb);

	s64 size;

	ntfs_volume *vol = NTFS_SB(sb);

	ntfs_inode *mft_ni = NTFS_I(vol->mft_ino);

	pgoff_t max_index;

	unsigned long flags;



	ntfs_debug("Entering.");

	/* Type of filesystem. */
@@ -2158,10 +2153,20 @@ static int ntfs_statfs(struct super_block *sb, struct kstatfs *sfs) 
	sfs->f_bavail = sfs->f_bfree = size;

	/* Serialize accesses to the inode bitmap. */

	down_read(&vol->mftbmp_lock);

	read_lock_irqsave(&mft_ni->size_lock, flags);

	size = i_size_read(vol->mft_ino) >> vol->mft_record_size_bits;

	/*

	 * Convert the maximum number of set bits into bytes rounded up, then

	 * convert into multiples of PAGE_CACHE_SIZE, rounding up so that if we

	 * have one full and one partial page max_index = 2.

	 */

	max_index = ((((mft_ni->initialized_size >> vol->mft_record_size_bits)

			+ 7) >> 3) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;

	read_unlock_irqrestore(&mft_ni->size_lock, flags);

	/* Number of inodes in file system (at this point in time). */

	sfs->f_files = vol->mft_ino->i_size >> vol->mft_record_size_bits;

	sfs->f_files = size;

	/* Free inodes in fs (based on current total count). */

	sfs->f_ffree = __get_nr_free_mft_records(vol);

	sfs->f_ffree = __get_nr_free_mft_records(vol, size, max_index);

	up_read(&vol->mftbmp_lock);

	/*

	 * File system id. This is extremely *nix flavour dependent and even
@@ -2347,7 +2352,8 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent) 
	}



	/* Get the size of the device in units of NTFS_BLOCK_SIZE bytes. */

	vol->nr_blocks = sb->s_bdev->bd_inode->i_size >> NTFS_BLOCK_SIZE_BITS;

	vol->nr_blocks = i_size_read(sb->s_bdev->bd_inode) >>

			NTFS_BLOCK_SIZE_BITS;



	/* Read the boot sector and return unlocked buffer head to it. */

	if (!(bh = read_ntfs_boot_sector(sb, silent))) {