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: Anton Altaparmakov <aia21@cantab.net>
diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
index 212a3d0..0ad0c51 100644
--- a/fs/ntfs/super.c
+++ b/fs/ntfs/super.c
@@ -990,12 +990,12 @@
*/
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_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 @@
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 @@
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_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 @@
* 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 @@
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 @@
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 @@
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 @@
*/
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 @@
* 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 @@
/**
* __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 @@
*
* 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 @@
* 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 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 @@
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 @@
}
/* 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))) {