Powerpc architecture supports 16GB hugetlb pages with hash translation. For 4K
page size, this is implemented as a hugepage directory entry at the PGD level
and for 64K it is implemented as a huge page pte at the PUD level
Hugetlbfs sets up file system blocksize same as page size and this patch
switches blocks size usage with 16GB hugetlb to use size_t type.
We only change generic code and hugetlbfs related usage of i_blocksize(). Other
fs specific usage is left unchanged in this patch. A large part of this change
is not relevant to hugetlb, but it is changed to make sure we track block size
using size_t in generic code.
Only functionality w.r.t getattr is observed to be impacted by this change.
The below test shows the user-visible change.
struct stat a;
stat("/mnt/a", &a);
printf("st_blksize = %ld\n", a.st_blksize);
Without patch
# ./a.out /mnt/a
st_blksize = 0
#
With patch
# ./a.out /mnt/a
st_blksize = 17179869184
#
Statx still has the problem
# stat /mnt/a
File: /mnt/a
Size: 0 Blocks: 0 IO Block: 512 regular empty file
Device: 2eh/46d Inode: 74584 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Context: unconfined_u:object_r:hugetlbfs_t:s0
Access: 2022-09-07 11:42:14.620239084 -0500
Modify: 2022-09-07 11:42:14.620239084 -0500
Change: 2022-09-07 11:42:14.620239084 -0500
Birth: -
because it uses __u32 stx_blksize in uapi.
struct statx {
/* 0x00 */
__u32 stx_mask; /* What results were written [uncond] */
__u32 stx_blksize; /* Preferred general I/O size [uncond] */
Fixing statx requires a syscall change where we add STATX_64BLOCKSIZE.
The change also fixes the below report warning.
UBSAN: shift-out-of-bounds in ./include/linux/fs.h:709:12
shift exponent 34 is too large for 32-bit type 'int'
CPU: 67 PID: 1632 Comm: bash Not tainted 6.0.0-rc2-00327-gee88a56e8517-dirty #1
Call Trace:
[c000000021517990] [c000000000cb21e4] dump_stack_lvl+0x98/0xe0 (unreliable)
[c0000000215179d0] [c000000000cacf60] ubsan_epilogue+0x18/0x70
[c000000021517a30] [c000000000cac44c] __ubsan_handle_shift_out_of_bounds+0x1bc/0x390
[c000000021517b30] [c00000000067e5b8] generic_fillattr+0x1b8/0x1d0
[c000000021517b70] [c00000000067e6ec] vfs_getattr_nosec+0x11c/0x140
[c000000021517bb0] [c00000000067e888] vfs_statx+0xd8/0x1d0
[c000000021517c30] [c00000000067f658] vfs_fstatat+0x88/0xd0
[c000000021517c80] [c00000000067f6e0] __do_sys_newstat+0x40/0x90
[c000000021517d50] [c00000000003cde0] system_call_exception+0x250/0x600
[c000000021517e10] [c00000000000c3bc] system_call_common+0xec/0x250
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
---
fs/buffer.c | 6 +++---
fs/dax.c | 2 +-
fs/iomap/buffered-io.c | 6 +++---
fs/iomap/direct-io.c | 2 +-
include/linux/fs.h | 4 ++--
include/linux/stat.h | 2 +-
mm/truncate.c | 2 +-
7 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index 55e762a58eb6..15def791325e 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2376,7 +2376,7 @@ static int cont_expand_zero(struct file *file, struct address_space *mapping,
{
struct inode *inode = mapping->host;
const struct address_space_operations *aops = mapping->a_ops;
- unsigned int blocksize = i_blocksize(inode);
+ size_t blocksize = i_blocksize(inode);
struct page *page;
void *fsdata;
pgoff_t index, curidx;
@@ -2454,7 +2454,7 @@ int cont_write_begin(struct file *file, struct address_space *mapping,
get_block_t *get_block, loff_t *bytes)
{
struct inode *inode = mapping->host;
- unsigned int blocksize = i_blocksize(inode);
+ size_t blocksize = i_blocksize(inode);
unsigned int zerofrom;
int err;
@@ -2542,7 +2542,7 @@ int block_truncate_page(struct address_space *mapping,
{
pgoff_t index = from >> PAGE_SHIFT;
unsigned offset = from & (PAGE_SIZE-1);
- unsigned blocksize;
+ size_t blocksize;
sector_t iblock;
unsigned length, pos;
struct inode *inode = mapping->host;
diff --git a/fs/dax.c b/fs/dax.c
index c440dcef4b1b..66673ef56695 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1304,7 +1304,7 @@ EXPORT_SYMBOL_GPL(dax_zero_range);
int dax_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
const struct iomap_ops *ops)
{
- unsigned int blocksize = i_blocksize(inode);
+ size_t blocksize = i_blocksize(inode);
unsigned int off = pos & (blocksize - 1);
/* Block boundary? Nothing to do */
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index ca5c62901541..4b67018c6e71 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -955,7 +955,7 @@ int
iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
const struct iomap_ops *ops)
{
- unsigned int blocksize = i_blocksize(inode);
+ size_t blocksize = i_blocksize(inode);
unsigned int off = pos & (blocksize - 1);
/* Block boundary? Nothing to do */
@@ -1297,7 +1297,7 @@ iomap_add_to_ioend(struct inode *inode, loff_t pos, struct folio *folio,
struct writeback_control *wbc, struct list_head *iolist)
{
sector_t sector = iomap_sector(&wpc->iomap, pos);
- unsigned len = i_blocksize(inode);
+ size_t len = i_blocksize(inode);
size_t poff = offset_in_folio(folio, pos);
if (!wpc->ioend || !iomap_can_add_to_ioend(wpc, pos, sector)) {
@@ -1340,7 +1340,7 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc,
{
struct iomap_page *iop = iomap_page_create(inode, folio, 0);
struct iomap_ioend *ioend, *next;
- unsigned len = i_blocksize(inode);
+ size_t len = i_blocksize(inode);
unsigned nblocks = i_blocks_per_folio(inode, folio);
u64 pos = folio_pos(folio);
int error = 0, count = 0, i;
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 4eb559a16c9e..d17d9e11cd35 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -241,7 +241,7 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter,
const struct iomap *iomap = &iter->iomap;
struct inode *inode = iter->inode;
unsigned int blkbits = blksize_bits(bdev_logical_block_size(iomap->bdev));
- unsigned int fs_block_size = i_blocksize(inode), pad;
+ size_t fs_block_size = i_blocksize(inode), pad;
loff_t length = iomap_length(iter);
loff_t pos = iter->pos;
blk_opf_t bio_opf;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9eced4cc286e..7fedf9dbcac3 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -704,9 +704,9 @@ struct inode {
struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode);
-static inline unsigned int i_blocksize(const struct inode *node)
+static inline size_t i_blocksize(const struct inode *node)
{
- return (1 << node->i_blkbits);
+ return (1UL << node->i_blkbits);
}
static inline int inode_unhashed(struct inode *inode)
diff --git a/include/linux/stat.h b/include/linux/stat.h
index 7df06931f25d..f362a8d1af0c 100644
--- a/include/linux/stat.h
+++ b/include/linux/stat.h
@@ -23,7 +23,7 @@ struct kstat {
u32 result_mask; /* What fields the user got */
umode_t mode;
unsigned int nlink;
- uint32_t blksize; /* Preferred I/O size */
+ size_t blksize; /* Preferred I/O size */
u64 attributes;
u64 attributes_mask;
#define KSTAT_ATTR_FS_IOC_FLAGS \
diff --git a/mm/truncate.c b/mm/truncate.c
index 0b0708bf935f..9d4b298d4f83 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -800,7 +800,7 @@ EXPORT_SYMBOL(truncate_setsize);
*/
void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to)
{
- int bsize = i_blocksize(inode);
+ size_t bsize = i_blocksize(inode);
loff_t rounded_from;
struct page *page;
pgoff_t index;
--
2.37.3
