From: David Laight <david.laight.linux@gmail.com>
min_t(unsigned int, a, b) casts an 'unsigned long' to 'unsigned int'.
Use min(a, b) instead as it promotes any 'unsigned int' to 'unsigned long'
and so cannot discard significant bits.
A couple of places need umin() because of loops like:
nfolios = DIV_ROUND_UP(ret + start, PAGE_SIZE);
for (i = 0; i < nfolios; i++) {
struct folio *folio = page_folio(pages[i]);
...
unsigned int len = umin(ret, PAGE_SIZE - start);
...
ret -= len;
...
}
where the compiler doesn't track things well enough to know that
'ret' is never negative.
The alternate loop:
for (i = 0; ret > 0; i++) {
struct folio *folio = page_folio(pages[i]);
...
unsigned int len = min(ret, PAGE_SIZE - start);
...
ret -= len;
...
}
would be equivalent and doesn't need 'nfolios'.
Most of the 'unsigned long' actually come from PAGE_SIZE.
Detected by an extra check added to min_t().
Signed-off-by: David Laight <david.laight.linux@gmail.com>
---
fs/buffer.c | 2 +-
fs/exec.c | 2 +-
fs/ext4/mballoc.c | 3 +--
fs/ext4/resize.c | 2 +-
fs/ext4/super.c | 2 +-
fs/fat/dir.c | 4 ++--
fs/fat/file.c | 3 +--
fs/fuse/dev.c | 2 +-
fs/fuse/file.c | 8 +++-----
fs/splice.c | 2 +-
10 files changed, 13 insertions(+), 17 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index 6a8752f7bbed..26c4c760b6c6 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2354,7 +2354,7 @@ bool block_is_partially_uptodate(struct folio *folio, size_t from, size_t count)
if (!head)
return false;
blocksize = head->b_size;
- to = min_t(unsigned, folio_size(folio) - from, count);
+ to = min(folio_size(folio) - from, count);
to = from + to;
if (from < blocksize && to > folio_size(folio) - blocksize)
return false;
diff --git a/fs/exec.c b/fs/exec.c
index 4298e7e08d5d..6d699e48df82 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -555,7 +555,7 @@ int copy_string_kernel(const char *arg, struct linux_binprm *bprm)
return -E2BIG;
while (len > 0) {
- unsigned int bytes_to_copy = min_t(unsigned int, len,
+ unsigned int bytes_to_copy = min(len,
min_not_zero(offset_in_page(pos), PAGE_SIZE));
struct page *page;
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 9087183602e4..cb68ea974de6 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4254,8 +4254,7 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
* get the corresponding group metadata to work with.
* For this we have goto again loop.
*/
- thisgrp_len = min_t(unsigned int, (unsigned int)len,
- EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff));
+ thisgrp_len = min(len, EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff));
clen = EXT4_NUM_B2C(sbi, thisgrp_len);
if (!ext4_sb_block_valid(sb, NULL, block, thisgrp_len)) {
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 050f26168d97..76842f0957b5 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1479,7 +1479,7 @@ static void ext4_update_super(struct super_block *sb,
/* Update the global fs size fields */
sbi->s_groups_count += flex_gd->count;
- sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
+ sbi->s_blockfile_groups = min(sbi->s_groups_count,
(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
/* Update the reserved block counts only once the new group is
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 33e7c08c9529..e116fe48ff43 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4830,7 +4830,7 @@ static int ext4_check_geometry(struct super_block *sb,
return -EINVAL;
}
sbi->s_groups_count = blocks_count;
- sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
+ sbi->s_blockfile_groups = min(sbi->s_groups_count,
(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
le32_to_cpu(es->s_inodes_count)) {
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 92b091783966..8375e7fbc1a5 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -1353,7 +1353,7 @@ int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
/* Fill the long name slots. */
for (i = 0; i < long_bhs; i++) {
- int copy = min_t(int, sb->s_blocksize - offset, size);
+ int copy = umin(sb->s_blocksize - offset, size);
memcpy(bhs[i]->b_data + offset, slots, copy);
mark_buffer_dirty_inode(bhs[i], dir);
offset = 0;
@@ -1364,7 +1364,7 @@ int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
err = fat_sync_bhs(bhs, long_bhs);
if (!err && i < nr_bhs) {
/* Fill the short name slot. */
- int copy = min_t(int, sb->s_blocksize - offset, size);
+ int copy = umin(sb->s_blocksize - offset, size);
memcpy(bhs[i]->b_data + offset, slots, copy);
mark_buffer_dirty_inode(bhs[i], dir);
if (IS_DIRSYNC(dir))
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 4fc49a614fb8..f48435e586c7 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -140,8 +140,7 @@ static int fat_ioctl_fitrim(struct inode *inode, unsigned long arg)
if (copy_from_user(&range, user_range, sizeof(range)))
return -EFAULT;
- range.minlen = max_t(unsigned int, range.minlen,
- bdev_discard_granularity(sb->s_bdev));
+ range.minlen = max(range.minlen, bdev_discard_granularity(sb->s_bdev));
err = fat_trim_fs(inode, &range);
if (err < 0)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 132f38619d70..0c9fb0db1de1 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1813,7 +1813,7 @@ static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
goto out_iput;
folio_offset = ((index - folio->index) << PAGE_SHIFT) + offset;
- nr_bytes = min_t(unsigned, num, folio_size(folio) - folio_offset);
+ nr_bytes = min(num, folio_size(folio) - folio_offset);
nr_pages = (offset + nr_bytes + PAGE_SIZE - 1) >> PAGE_SHIFT;
err = fuse_copy_folio(cs, &folio, folio_offset, nr_bytes, 0);
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index f1ef77a0be05..f4ffa559ad26 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1252,10 +1252,8 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
static inline unsigned int fuse_wr_pages(loff_t pos, size_t len,
unsigned int max_pages)
{
- return min_t(unsigned int,
- ((pos + len - 1) >> PAGE_SHIFT) -
- (pos >> PAGE_SHIFT) + 1,
- max_pages);
+ return min(((pos + len - 1) >> PAGE_SHIFT) - (pos >> PAGE_SHIFT) + 1,
+ max_pages);
}
static ssize_t fuse_perform_write(struct kiocb *iocb, struct iov_iter *ii)
@@ -1550,7 +1548,7 @@ static int fuse_get_user_pages(struct fuse_args_pages *ap, struct iov_iter *ii,
struct folio *folio = page_folio(pages[i]);
unsigned int offset = start +
(folio_page_idx(folio, pages[i]) << PAGE_SHIFT);
- unsigned int len = min_t(unsigned int, ret, PAGE_SIZE - start);
+ unsigned int len = umin(ret, PAGE_SIZE - start);
ap->descs[ap->num_folios].offset = offset;
ap->descs[ap->num_folios].length = len;
diff --git a/fs/splice.c b/fs/splice.c
index f5094b6d00a0..41ce3a4ef74f 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1467,7 +1467,7 @@ static ssize_t iter_to_pipe(struct iov_iter *from,
n = DIV_ROUND_UP(left + start, PAGE_SIZE);
for (i = 0; i < n; i++) {
- int size = min_t(int, left, PAGE_SIZE - start);
+ int size = umin(left, PAGE_SIZE - start);
buf.page = pages[i];
buf.offset = start;
--
2.39.5On Wed, Nov 19, 2025 at 10:41:26PM +0000, david.laight.linux@gmail.com wrote:
> From: David Laight <david.laight.linux@gmail.com>
>
> min_t(unsigned int, a, b) casts an 'unsigned long' to 'unsigned int'.
> Use min(a, b) instead as it promotes any 'unsigned int' to 'unsigned long'
> and so cannot discard significant bits.
This breaks an arm imx_v6_v7_defconfig build:
In file included from <command-line>:
In function 'fuse_wr_pages',
inlined from 'fuse_perform_write' at /home/broonie/git/bisect/fs/fuse/file.c:1347:27:
/home/broonie/git/bisect/include/linux/compiler_types.h:630:45: error: call to '__compiletime_assert_434' declared with attribute error: min(((pos + len - 1) >> 12) - (pos >> 12) + 1, max_pages) signedness error
630 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^
/home/broonie/git/bisect/include/linux/compiler_types.h:611:25: note: in definition of macro '__compiletime_assert'
611 | prefix ## suffix(); \
| ^~~~~~
/home/broonie/git/bisect/include/linux/compiler_types.h:630:9: note: in expansion of macro '_compiletime_assert'
630 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^~~~~~~~~~~~~~~~~~~
/home/broonie/git/bisect/include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
| ^~~~~~~~~~~~~~~~~~
/home/broonie/git/bisect/include/linux/minmax.h:93:9: note: in expansion of macro 'BUILD_BUG_ON_MSG'
93 | BUILD_BUG_ON_MSG(!__types_ok(ux, uy), \
| ^~~~~~~~~~~~~~~~
/home/broonie/git/bisect/include/linux/minmax.h:98:9: note: in expansion of macro '__careful_cmp_once'
98 | __careful_cmp_once(op, x, y, __UNIQUE_ID(x_), __UNIQUE_ID(y_))
| ^~~~~~~~~~~~~~~~~~
/home/broonie/git/bisect/include/linux/minmax.h:105:25: note: in expansion of macro '__careful_cmp'
105 | #define min(x, y) __careful_cmp(min, x, y)
| ^~~~~~~~~~~~~
/home/broonie/git/bisect/fs/fuse/file.c:1326:16: note: in expansion of macro 'min'
1326 | return min(((pos + len - 1) >> PAGE_SHIFT) - (pos >> PAGE_SHIFT) + 1,
| ^~~
On Tue, 13 Jan 2026 16:56:56 +0000 Mark Brown <broonie@kernel.org> wrote: > On Wed, Nov 19, 2025 at 10:41:26PM +0000, david.laight.linux@gmail.com wrote: > > From: David Laight <david.laight.linux@gmail.com> > > > > min_t(unsigned int, a, b) casts an 'unsigned long' to 'unsigned int'. > > Use min(a, b) instead as it promotes any 'unsigned int' to 'unsigned long' > > and so cannot discard significant bits. > > This breaks an arm imx_v6_v7_defconfig build: I hadn't tested 32bit when I sent the patch. It was noticed ages ago and I thought there was a patch (to fuse/file.c) that changed the code to avoid the 64bit signed maths on 32bit. David > > In file included from <command-line>: > In function 'fuse_wr_pages', > inlined from 'fuse_perform_write' at /home/broonie/git/bisect/fs/fuse/file.c:1347:27: > /home/broonie/git/bisect/include/linux/compiler_types.h:630:45: error: call to '__compiletime_assert_434' declared with attribute error: min(((pos + len - 1) >> 12) - (pos >> 12) + 1, max_pages) signedness error > 630 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) > | ^ > /home/broonie/git/bisect/include/linux/compiler_types.h:611:25: note: in definition of macro '__compiletime_assert' > 611 | prefix ## suffix(); \ > | ^~~~~~ > /home/broonie/git/bisect/include/linux/compiler_types.h:630:9: note: in expansion of macro '_compiletime_assert' > 630 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) > | ^~~~~~~~~~~~~~~~~~~ > /home/broonie/git/bisect/include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert' > 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) > | ^~~~~~~~~~~~~~~~~~ > /home/broonie/git/bisect/include/linux/minmax.h:93:9: note: in expansion of macro 'BUILD_BUG_ON_MSG' > 93 | BUILD_BUG_ON_MSG(!__types_ok(ux, uy), \ > | ^~~~~~~~~~~~~~~~ > /home/broonie/git/bisect/include/linux/minmax.h:98:9: note: in expansion of macro '__careful_cmp_once' > 98 | __careful_cmp_once(op, x, y, __UNIQUE_ID(x_), __UNIQUE_ID(y_)) > | ^~~~~~~~~~~~~~~~~~ > /home/broonie/git/bisect/include/linux/minmax.h:105:25: note: in expansion of macro '__careful_cmp' > 105 | #define min(x, y) __careful_cmp(min, x, y) > | ^~~~~~~~~~~~~ > /home/broonie/git/bisect/fs/fuse/file.c:1326:16: note: in expansion of macro 'min' > 1326 | return min(((pos + len - 1) >> PAGE_SHIFT) - (pos >> PAGE_SHIFT) + 1, > | ^~~
On Tue, 13 Jan 2026 18:33:46 +0000 David Laight <david.laight.linux@gmail.com> wrote: > On Tue, 13 Jan 2026 16:56:56 +0000 > Mark Brown <broonie@kernel.org> wrote: > > > On Wed, Nov 19, 2025 at 10:41:26PM +0000, david.laight.linux@gmail.com wrote: > > > From: David Laight <david.laight.linux@gmail.com> > > > > > > min_t(unsigned int, a, b) casts an 'unsigned long' to 'unsigned int'. > > > Use min(a, b) instead as it promotes any 'unsigned int' to 'unsigned long' > > > and so cannot discard significant bits. > > > > This breaks an arm imx_v6_v7_defconfig build: > > I hadn't tested 32bit when I sent the patch. > It was noticed ages ago and I thought there was a patch (to fuse/file.c) that > changed the code to avoid the 64bit signed maths on 32bit. I've just sent in a patch to fix it, compile tested for 32bit x86. David > > > > In file included from <command-line>: > > In function 'fuse_wr_pages', > > inlined from 'fuse_perform_write' at /home/broonie/git/bisect/fs/fuse/file.c:1347:27: > > /home/broonie/git/bisect/include/linux/compiler_types.h:630:45: error: call to '__compiletime_assert_434' declared with attribute error: min(((pos + len - 1) >> 12) - (pos >> 12) + 1, max_pages) signedness error ... ^~~~~~~~~~~~~ > > /home/broonie/git/bisect/fs/fuse/file.c:1326:16: note: in expansion of macro 'min' > > 1326 | return min(((pos + len - 1) >> PAGE_SHIFT) - (pos >> PAGE_SHIFT) + 1, > > | ^~~ >
On Tue, Jan 13, 2026 at 06:33:46PM +0000, David Laight wrote: > Mark Brown <broonie@kernel.org> wrote: > > On Wed, Nov 19, 2025 at 10:41:26PM +0000, david.laight.linux@gmail.com wrote: > > This breaks an arm imx_v6_v7_defconfig build: > I hadn't tested 32bit when I sent the patch. > It was noticed ages ago and I thought there was a patch (to fuse/file.c) that > changed the code to avoid the 64bit signed maths on 32bit. It's possible there's a patch out there somewhere but it's not present in what's in -next.
Hi David,
On Wed, Nov 19, 2025 at 10:41:26PM +0000, david.laight.linux@gmail.com wrote:
> From: David Laight <david.laight.linux@gmail.com>
>
> min_t(unsigned int, a, b) casts an 'unsigned long' to 'unsigned int'.
> Use min(a, b) instead as it promotes any 'unsigned int' to 'unsigned long'
> and so cannot discard significant bits.
>
> A couple of places need umin() because of loops like:
> nfolios = DIV_ROUND_UP(ret + start, PAGE_SIZE);
>
> for (i = 0; i < nfolios; i++) {
> struct folio *folio = page_folio(pages[i]);
> ...
> unsigned int len = umin(ret, PAGE_SIZE - start);
> ...
> ret -= len;
> ...
> }
> where the compiler doesn't track things well enough to know that
> 'ret' is never negative.
>
> The alternate loop:
> for (i = 0; ret > 0; i++) {
> struct folio *folio = page_folio(pages[i]);
> ...
> unsigned int len = min(ret, PAGE_SIZE - start);
> ...
> ret -= len;
> ...
> }
> would be equivalent and doesn't need 'nfolios'.
>
> Most of the 'unsigned long' actually come from PAGE_SIZE.
>
> Detected by an extra check added to min_t().
>
> Signed-off-by: David Laight <david.laight.linux@gmail.com>
When doing a mips cross compile from an arm64 host
(via ARCH=mips CROSS_COMPILE=mips64-linux-gnu- make), the following
build error occurs in linux-next and goes away when I revert this
commit.
In file included from <command-line>:
In function ‘fuse_wr_pages’,
inlined from ‘fuse_perform_write’ at fs/fuse/file.c:1347:27:
././include/linux/compiler_types.h:667:45: error: call to ‘__compiletime_assert_405’ declared with attribute error: min(((pos + len
- 1) >> 12) - (pos >> 12) + 1, max_pages) signedness error
667 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^
././include/linux/compiler_types.h:648:25: note: in definition of macro ‘__compiletime_assert’
648 | prefix ## suffix(); \
| ^~~~~~
././include/linux/compiler_types.h:667:9: note: in expansion of macro ‘_compiletime_assert’
667 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^~~~~~~~~~~~~~~~~~~
./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
| ^~~~~~~~~~~~~~~~~~
./include/linux/minmax.h:93:9: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
93 | BUILD_BUG_ON_MSG(!__types_ok(ux, uy), \
| ^~~~~~~~~~~~~~~~
./include/linux/minmax.h:98:9: note: in expansion of macro ‘__careful_cmp_once’
98 | __careful_cmp_once(op, x, y, __UNIQUE_ID(x_), __UNIQUE_ID(y_))
| ^~~~~~~~~~~~~~~~~~
./include/linux/minmax.h:105:25: note: in expansion of macro ‘__careful_cmp’
105 | #define min(x, y) __careful_cmp(min, x, y)
| ^~~~~~~~~~~~~
fs/fuse/file.c:1326:16: note: in expansion of macro ‘min’
1326 | return min(((pos + len - 1) >> PAGE_SHIFT) - (pos >> PAGE_SHIFT) + 1,
| ^~~
This is on a cento-stream-10 host running
gcc version 14.3.1 20250617 (Red Hat 14.3.1-2) (GCC). I didn't look into
this in detail, and I'm not entirely sure what the correct fix here
should be.
Brian
On Mon, 12 Jan 2026 16:51:22 -0500
Brian Masney <bmasney@redhat.com> wrote:
> Hi David,
>
> On Wed, Nov 19, 2025 at 10:41:26PM +0000, david.laight.linux@gmail.com wrote:
> > From: David Laight <david.laight.linux@gmail.com>
> >
> > min_t(unsigned int, a, b) casts an 'unsigned long' to 'unsigned int'.
> > Use min(a, b) instead as it promotes any 'unsigned int' to 'unsigned long'
> > and so cannot discard significant bits.
> >
> > A couple of places need umin() because of loops like:
> > nfolios = DIV_ROUND_UP(ret + start, PAGE_SIZE);
> >
> > for (i = 0; i < nfolios; i++) {
> > struct folio *folio = page_folio(pages[i]);
> > ...
> > unsigned int len = umin(ret, PAGE_SIZE - start);
> > ...
> > ret -= len;
> > ...
> > }
> > where the compiler doesn't track things well enough to know that
> > 'ret' is never negative.
> >
> > The alternate loop:
> > for (i = 0; ret > 0; i++) {
> > struct folio *folio = page_folio(pages[i]);
> > ...
> > unsigned int len = min(ret, PAGE_SIZE - start);
> > ...
> > ret -= len;
> > ...
> > }
> > would be equivalent and doesn't need 'nfolios'.
> >
> > Most of the 'unsigned long' actually come from PAGE_SIZE.
> >
> > Detected by an extra check added to min_t().
> >
> > Signed-off-by: David Laight <david.laight.linux@gmail.com>
>
> When doing a mips cross compile from an arm64 host
> (via ARCH=mips CROSS_COMPILE=mips64-linux-gnu- make), the following
> build error occurs in linux-next and goes away when I revert this
> commit.
I've looked at this one before.
I think there is another patch lurking to fix it.
> In file included from <command-line>:
> In function ‘fuse_wr_pages’,
> inlined from ‘fuse_perform_write’ at fs/fuse/file.c:1347:27:
> ././include/linux/compiler_types.h:667:45: error: call to ‘__compiletime_assert_405’ declared with attribute error: min(((pos + len
> - 1) >> 12) - (pos >> 12) + 1, max_pages) signedness error
...
> fs/fuse/file.c:1326:16: note: in expansion of macro ‘min’
> 1326 | return min(((pos + len - 1) >> PAGE_SHIFT) - (pos >> PAGE_SHIFT) + 1,
max_pages);
'len' is 'unsigned long' and the expression is unsigned on 64bit.
But 'pos' is s64 so the expression is signed on 32bit.
IIRC the final version might have been (equivalent to):
len += pos & (PAGE_SIZE - 1);
return min(DIV_ROUND_UP(len, PAGE_SIZE), max_pages);
which generates much better code as well (no 64bit maths).
I don't think len can overflow, read/write are limited to INT_MAX - PAGE_SIZE
bytes in the syscall interface.
David
>
> This is on a cento-stream-10 host running
> gcc version 14.3.1 20250617 (Red Hat 14.3.1-2) (GCC). I didn't look into
> this in detail, and I'm not entirely sure what the correct fix here
> should be.
>
> Brian
>
On Wed, Nov 19, 2025 at 10:41:26PM +0000, david.laight.linux@gmail.com wrote:
> From: David Laight <david.laight.linux@gmail.com>
>
> min_t(unsigned int, a, b) casts an 'unsigned long' to 'unsigned int'.
> Use min(a, b) instead as it promotes any 'unsigned int' to 'unsigned long'
> and so cannot discard significant bits.
>
> A couple of places need umin() because of loops like:
> nfolios = DIV_ROUND_UP(ret + start, PAGE_SIZE);
>
> for (i = 0; i < nfolios; i++) {
> struct folio *folio = page_folio(pages[i]);
> ...
> unsigned int len = umin(ret, PAGE_SIZE - start);
> ...
> ret -= len;
> ...
> }
> where the compiler doesn't track things well enough to know that
> 'ret' is never negative.
>
> The alternate loop:
> for (i = 0; ret > 0; i++) {
> struct folio *folio = page_folio(pages[i]);
> ...
> unsigned int len = min(ret, PAGE_SIZE - start);
> ...
> ret -= len;
> ...
> }
> would be equivalent and doesn't need 'nfolios'.
>
> Most of the 'unsigned long' actually come from PAGE_SIZE.
>
> Detected by an extra check added to min_t().
>
> Signed-off-by: David Laight <david.laight.linux@gmail.com>
> ---
Too late for this cycle but we will pick this up next cycle!
> fs/buffer.c | 2 +-
> fs/exec.c | 2 +-
> fs/ext4/mballoc.c | 3 +--
> fs/ext4/resize.c | 2 +-
> fs/ext4/super.c | 2 +-
> fs/fat/dir.c | 4 ++--
> fs/fat/file.c | 3 +--
> fs/fuse/dev.c | 2 +-
> fs/fuse/file.c | 8 +++-----
> fs/splice.c | 2 +-
> 10 files changed, 13 insertions(+), 17 deletions(-)
>
> diff --git a/fs/buffer.c b/fs/buffer.c
> index 6a8752f7bbed..26c4c760b6c6 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -2354,7 +2354,7 @@ bool block_is_partially_uptodate(struct folio *folio, size_t from, size_t count)
> if (!head)
> return false;
> blocksize = head->b_size;
> - to = min_t(unsigned, folio_size(folio) - from, count);
> + to = min(folio_size(folio) - from, count);
> to = from + to;
> if (from < blocksize && to > folio_size(folio) - blocksize)
> return false;
> diff --git a/fs/exec.c b/fs/exec.c
> index 4298e7e08d5d..6d699e48df82 100644
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -555,7 +555,7 @@ int copy_string_kernel(const char *arg, struct linux_binprm *bprm)
> return -E2BIG;
>
> while (len > 0) {
> - unsigned int bytes_to_copy = min_t(unsigned int, len,
> + unsigned int bytes_to_copy = min(len,
> min_not_zero(offset_in_page(pos), PAGE_SIZE));
> struct page *page;
>
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 9087183602e4..cb68ea974de6 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -4254,8 +4254,7 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
> * get the corresponding group metadata to work with.
> * For this we have goto again loop.
> */
> - thisgrp_len = min_t(unsigned int, (unsigned int)len,
> - EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff));
> + thisgrp_len = min(len, EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff));
> clen = EXT4_NUM_B2C(sbi, thisgrp_len);
>
> if (!ext4_sb_block_valid(sb, NULL, block, thisgrp_len)) {
> diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
> index 050f26168d97..76842f0957b5 100644
> --- a/fs/ext4/resize.c
> +++ b/fs/ext4/resize.c
> @@ -1479,7 +1479,7 @@ static void ext4_update_super(struct super_block *sb,
>
> /* Update the global fs size fields */
> sbi->s_groups_count += flex_gd->count;
> - sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
> + sbi->s_blockfile_groups = min(sbi->s_groups_count,
> (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
>
> /* Update the reserved block counts only once the new group is
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 33e7c08c9529..e116fe48ff43 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -4830,7 +4830,7 @@ static int ext4_check_geometry(struct super_block *sb,
> return -EINVAL;
> }
> sbi->s_groups_count = blocks_count;
> - sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
> + sbi->s_blockfile_groups = min(sbi->s_groups_count,
> (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
> if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
> le32_to_cpu(es->s_inodes_count)) {
> diff --git a/fs/fat/dir.c b/fs/fat/dir.c
> index 92b091783966..8375e7fbc1a5 100644
> --- a/fs/fat/dir.c
> +++ b/fs/fat/dir.c
> @@ -1353,7 +1353,7 @@ int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
>
> /* Fill the long name slots. */
> for (i = 0; i < long_bhs; i++) {
> - int copy = min_t(int, sb->s_blocksize - offset, size);
> + int copy = umin(sb->s_blocksize - offset, size);
> memcpy(bhs[i]->b_data + offset, slots, copy);
> mark_buffer_dirty_inode(bhs[i], dir);
> offset = 0;
> @@ -1364,7 +1364,7 @@ int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
> err = fat_sync_bhs(bhs, long_bhs);
> if (!err && i < nr_bhs) {
> /* Fill the short name slot. */
> - int copy = min_t(int, sb->s_blocksize - offset, size);
> + int copy = umin(sb->s_blocksize - offset, size);
> memcpy(bhs[i]->b_data + offset, slots, copy);
> mark_buffer_dirty_inode(bhs[i], dir);
> if (IS_DIRSYNC(dir))
> diff --git a/fs/fat/file.c b/fs/fat/file.c
> index 4fc49a614fb8..f48435e586c7 100644
> --- a/fs/fat/file.c
> +++ b/fs/fat/file.c
> @@ -140,8 +140,7 @@ static int fat_ioctl_fitrim(struct inode *inode, unsigned long arg)
> if (copy_from_user(&range, user_range, sizeof(range)))
> return -EFAULT;
>
> - range.minlen = max_t(unsigned int, range.minlen,
> - bdev_discard_granularity(sb->s_bdev));
> + range.minlen = max(range.minlen, bdev_discard_granularity(sb->s_bdev));
>
> err = fat_trim_fs(inode, &range);
> if (err < 0)
> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> index 132f38619d70..0c9fb0db1de1 100644
> --- a/fs/fuse/dev.c
> +++ b/fs/fuse/dev.c
> @@ -1813,7 +1813,7 @@ static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
> goto out_iput;
>
> folio_offset = ((index - folio->index) << PAGE_SHIFT) + offset;
> - nr_bytes = min_t(unsigned, num, folio_size(folio) - folio_offset);
> + nr_bytes = min(num, folio_size(folio) - folio_offset);
> nr_pages = (offset + nr_bytes + PAGE_SIZE - 1) >> PAGE_SHIFT;
>
> err = fuse_copy_folio(cs, &folio, folio_offset, nr_bytes, 0);
> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> index f1ef77a0be05..f4ffa559ad26 100644
> --- a/fs/fuse/file.c
> +++ b/fs/fuse/file.c
> @@ -1252,10 +1252,8 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
> static inline unsigned int fuse_wr_pages(loff_t pos, size_t len,
> unsigned int max_pages)
> {
> - return min_t(unsigned int,
> - ((pos + len - 1) >> PAGE_SHIFT) -
> - (pos >> PAGE_SHIFT) + 1,
> - max_pages);
> + return min(((pos + len - 1) >> PAGE_SHIFT) - (pos >> PAGE_SHIFT) + 1,
> + max_pages);
> }
>
> static ssize_t fuse_perform_write(struct kiocb *iocb, struct iov_iter *ii)
> @@ -1550,7 +1548,7 @@ static int fuse_get_user_pages(struct fuse_args_pages *ap, struct iov_iter *ii,
> struct folio *folio = page_folio(pages[i]);
> unsigned int offset = start +
> (folio_page_idx(folio, pages[i]) << PAGE_SHIFT);
> - unsigned int len = min_t(unsigned int, ret, PAGE_SIZE - start);
> + unsigned int len = umin(ret, PAGE_SIZE - start);
>
> ap->descs[ap->num_folios].offset = offset;
> ap->descs[ap->num_folios].length = len;
> diff --git a/fs/splice.c b/fs/splice.c
> index f5094b6d00a0..41ce3a4ef74f 100644
> --- a/fs/splice.c
> +++ b/fs/splice.c
> @@ -1467,7 +1467,7 @@ static ssize_t iter_to_pipe(struct iov_iter *from,
>
> n = DIV_ROUND_UP(left + start, PAGE_SIZE);
> for (i = 0; i < n; i++) {
> - int size = min_t(int, left, PAGE_SIZE - start);
> + int size = umin(left, PAGE_SIZE - start);
>
> buf.page = pages[i];
> buf.offset = start;
> --
> 2.39.5
>
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