On Thu, Aug 16, 2007 at 09:45:34AM +0200, Peter Zijlstra wrote:
> alloc_percpu can fail, propagate that error.
>
> Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>
> ---
> fs/ext2/super.c | 11 ++++++++---
> fs/ext3/super.c | 11 ++++++++---
> fs/ext4/super.c | 11 ++++++++---
> include/linux/percpu_counter.h | 5 +++--
> lib/percpu_counter.c | 8 +++++++-
> 5 files changed, 34 insertions(+), 12 deletions(-)
>
> Index: linux-2.6/fs/ext2/super.c
> ===================================================================
> --- linux-2.6.orig/fs/ext2/super.c
> +++ linux-2.6/fs/ext2/super.c
> @@ -725,6 +725,7 @@ static int ext2_fill_super(struct super_
> int db_count;
> int i, j;
> __le32 features;
> + int err;
>
> sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
> if (!sbi)
> @@ -996,12 +997,16 @@ static int ext2_fill_super(struct super_
> sbi->s_rsv_window_head.rsv_goal_size = 0;
> ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
>
> - percpu_counter_init(&sbi->s_freeblocks_counter,
> + err = percpu_counter_init(&sbi->s_freeblocks_counter,
> ext2_count_free_blocks(sb));
> - percpu_counter_init(&sbi->s_freeinodes_counter,
> + err |= percpu_counter_init(&sbi->s_freeinodes_counter,
> ext2_count_free_inodes(sb));
> - percpu_counter_init(&sbi->s_dirs_counter,
> + err |= percpu_counter_init(&sbi->s_dirs_counter,
> ext2_count_dirs(sb));
> + if (err) {
> + printk(KERN_ERR "EXT2-fs: insufficient memory\n");
> + goto failed_mount3;
> + }
Can percpu_counter_init fail with only one error code? If not, the error
code potentially used in future at failed_mount3 could be nonsensical
because of the bitwise or-ing.
> Index: linux-2.6/lib/percpu_counter.c
> ===================================================================
> --- linux-2.6.orig/lib/percpu_counter.c
> +++ linux-2.6/lib/percpu_counter.c
> @@ -68,21 +68,27 @@ s64 __percpu_counter_sum(struct percpu_c
> }
> EXPORT_SYMBOL(__percpu_counter_sum);
>
> -void percpu_counter_init(struct percpu_counter *fbc, s64 amount)
> +int percpu_counter_init(struct percpu_counter *fbc, s64 amount)
> {
> spin_lock_init(&fbc->lock);
> fbc->count = amount;
> fbc->counters = alloc_percpu(s32);
> + if (!fbc->counters)
> + return -ENOMEM;
> #ifdef CONFIG_HOTPLUG_CPU
> mutex_lock(&percpu_counters_lock);
> list_add(&fbc->list, &percpu_counters);
> mutex_unlock(&percpu_counters_lock);
> #endif
> + return 0;
> }
I guess this answers my question. But I'd still be weary because a trivial
change here could produce very strange error codes in ext2/3/4.
Josef 'Jeff' Sipek.
--
Once you have their hardware. Never give it back.
(The First Rule of Hardware Acquisition)
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