[dm-devel] [PATCH] dm thin: make const array descs static
Don't populate the read-only const array ramp_base on the stack but
instead make it static. Add in a const to clean up checkpatch warning
too since the data and the pointer are const. Also makes the object
code a little smaller.
Signed-off-by: Colin Ian King
---
drivers/md/dm-thin.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index e76c96c760a9..d228177fdf35 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -293,7 +293,7 @@ static enum pool_mode get_pool_mode(struct pool *pool)
static void notify_of_pool_mode_change(struct pool *pool)
{
- const char *descs[] = {
+ static const char * const descs[] = {
"write",
"out-of-data-space",
"read-only",
--
2.37.3
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[dm-devel] [PATCH] dm: make static read-only array table const
The static array table as read-only so it make sense to make
it const. Add in the int type to clean up checkpatch warning.
Signed-off-by: Colin Ian King
---
drivers/md/dm-cache-policy-smq.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/md/dm-cache-policy-smq.c b/drivers/md/dm-cache-policy-smq.c
index b61aac00ff40..19eac5d980a8 100644
--- a/drivers/md/dm-cache-policy-smq.c
+++ b/drivers/md/dm-cache-policy-smq.c
@@ -1026,7 +1026,9 @@ static unsigned default_promote_level(struct smq_policy
*mq)
* This scheme reminds me of a graph of entropy vs probability of a
* binary variable.
*/
- static unsigned table[] = {1, 1, 1, 2, 4, 6, 7, 8, 7, 6, 4, 4, 3, 3, 2,
2, 1};
+ static const unsigned int table[] = {
+ 1, 1, 1, 2, 4, 6, 7, 8, 7, 6, 4, 4, 3, 3, 2, 2, 1
+ };
unsigned hits = mq->cache_stats.hits;
unsigned misses = mq->cache_stats.misses;
--
2.33.1
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Re: [dm-devel] dm: Forbid requeue of writes to zones
Hi,
Static analysis with Coverity on Linux next has found and issue in
drivers/md/dm.c with the following commit:
commit 2c243153d1d4be4e23735cd10984ac17c7a54531
Author: Damien Le Moal
Date: Wed May 26 06:24:58 2021 +0900
dm: Forbid requeue of writes to zones
The analysis is as follows:
828 static void dec_pending(struct dm_io *io, blk_status_t error)
829 {
830unsigned long flags;
831blk_status_t io_error;
1. var_decl: Declaring variable bio without initializer.
832struct bio *bio;
833struct mapped_device *md = io->md;
834
835/* Push-back supersedes any I/O errors */
2. Condition !!error, taking true branch.
836if (unlikely(error)) {
837spin_lock_irqsave(>endio_lock, flags);
3. Condition io->status == 11 /* (blk_status_t)11 */, taking false
branch.
838if (!(io->status == BLK_STS_DM_REQUEUE &&
__noflush_suspending(md)))
839io->status = error;
840spin_unlock_irqrestore(>endio_lock, flags);
841}
842
4. Condition atomic_dec_and_test(>io_count), taking true branch.
843if (atomic_dec_and_test(>io_count)) {
5. Condition io->status == 11 /* (blk_status_t)11 */, taking true
branch.
844if (io->status == BLK_STS_DM_REQUEUE) {
845/*
846 * Target requested pushing back the I/O.
847 */
848spin_lock_irqsave(>deferred_lock, flags);
6. Condition __noflush_suspending(md), taking true branch.
849if (__noflush_suspending(md) &&
Uninitialized pointer read
7. uninit_use_in_call: Using uninitialized value bio when calling
dm_is_zone_write.
850!WARN_ON_ONCE(dm_is_zone_write(md, bio)))
851/* NOTE early return due to
BLK_STS_DM_REQUEUE below */
852bio_list_add_head(>deferred,
io->orig_bio);
The pointer bio is not initialized and yet is being used in the call to
function dm_is_zone_write where pointer bio is being accessed. I'm not
sure what the original intent was, but this looks incorrect.
Colin
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[dm-devel] NAK: [PATCH][next] dm space maps: Fix uninitialized variable r2
On 21/05/2021 10:40, Colin King wrote:
> From: Colin Ian King
>
> In the case where recursing(mm) is true variable r2 is not
> inintialized and an uninitialized value is being used in the
> call combine_errors later on. Fix this by setting r2 to zero.
>
> Addresses-Coverity: ("Uninitialized scalar variable")
> Fixes: def6a7a9a7f0 ("dm space maps: improve performance with inc/dec on
> ranges of blocks")
> Signed-off-by: Colin Ian King
> ---
> drivers/md/persistent-data/dm-space-map-metadata.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c
> b/drivers/md/persistent-data/dm-space-map-metadata.c
> index 3b70ee861cf5..5be5ef4c831f 100644
> --- a/drivers/md/persistent-data/dm-space-map-metadata.c
> +++ b/drivers/md/persistent-data/dm-space-map-metadata.c
> @@ -432,9 +432,10 @@ static int sm_metadata_dec_blocks(struct dm_space_map
> *sm, dm_block_t b, dm_bloc
> int32_t nr_allocations;
> struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
>
> - if (recursing(smm))
> + if (recursing(smm)) {
> r = add_bop(smm, BOP_DEC, b, e);
> - else {
> + r2 = 0;
> + } else {
> in(smm);
> r = sm_ll_dec(>ll, b, e, _allocations);
> r2 = out(smm);
>
There is a another occurrence of this, I'll send a V2 shortly
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Re: [dm-devel] dm: rename multipath path selector source files to have "dm-ps" prefix
Hi,
Static analysis on linux-next has detected an initialized variable issue
with the following recent commit:
commit 28784347451fdbf4671ba97018f816041ba2306a
Author: Mike Snitzer
Date: Tue Nov 10 13:41:53 2020 -0500
dm: rename multipath path selector source files to have "dm-ps" prefix
The analysis is as follows:
43
static int ioa_add_path(struct path_selector *ps, struct dm_path *path,
44int argc, char **argv, char **error)
45 {
46struct selector *s = ps->context;
47struct path_info *pi = NULL;
1. var_decl: Declaring variable cpu without initializer.
48unsigned int cpu;
49int ret;
50
2. Condition argc != 1, taking false branch.
51if (argc != 1) {
52*error = "io-affinity ps: invalid number of arguments";
53return -EINVAL;
54}
55
Uninitialized scalar variable (UNINIT)
3. uninit_use_in_call: Using uninitialized value cpu when calling
__cpu_to_node.
56pi = kzalloc_node(sizeof(*pi), GFP_KERNEL, cpu_to_node(cpu));
57if (!pi) {
58*error = "io-affinity ps: Error allocating path context";
59return -ENOMEM;
60}
Colin
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Re: [dm-devel] [PATCH] dm ioctl: make dm_open and dm_release release
On 10/05/17 10:18, Colin King wrote:
> From: Colin Ian King <colin.k...@canonical.com>
>
> Making dm_open and dm_release static fixes the sparse warnings:
>
> warning: symbol 'dm_open' was not declared. Should it be static?
> warning: symbol 'dm_release' was not declared. Should it be static?
>
> Fixes: ab2c6224f4c0c ("dm: a basic support for using the select or poll
> function")
> Signed-off-by: Colin Ian King <colin.k...@canonical.com>
> ---
> drivers/md/dm-ioctl.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
> index 70dc5db90ef2..d45c68115d4c 100644
> --- a/drivers/md/dm-ioctl.c
> +++ b/drivers/md/dm-ioctl.c
> @@ -1893,7 +1893,7 @@ static long dm_compat_ctl_ioctl(struct file *file, uint
> command, ulong u)
> #define dm_compat_ctl_ioctl NULL
> #endif
>
> -int dm_open(struct inode *inode, struct file *filp)
> +static int dm_open(struct inode *inode, struct file *filp)
> {
> int r;
> struct dm_file *priv;
> @@ -1911,7 +1911,7 @@ int dm_open(struct inode *inode, struct file *filp)
> return 0;
> }
>
> -int dm_release(struct inode *inode, struct file *filp)
> +static int dm_release(struct inode *inode, struct file *filp)
> {
> kfree(filp->private_data);
> return 0;
>
Sorry, ignore this, it had a mistake in the subject line
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