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seq_file: add seq_cpumask(), seq_nodemask()

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Short enough reads from /proc/irq/*/smp_affinity return -EINVAL for no
good reason.

This became noticed with NR_CPUS=4096 patches, when length of printed
representation of cpumask becase 1152, but cat(1) continued to read with
1024-byte chunks.  bitmap_scnprintf() in good faith fills buffer, returns
1023, check returns -EINVAL.

Fix it by switching to seq_file, so handler will just fill buffer and
doesn't care about offsets, length, filling EOF and all this crap.

For that add seq_bitmap(), and wrappers around it -- seq_cpumask() and
seq_nodemask().

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Paul Jackson <pj@sgi.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alexey Dobriyan
2008-08-12 15:09:02 -07:00
committed by Linus Torvalds
parent dd763460eb
commit 50ac2d694f
4 changed files with 38 additions and 0 deletions
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14
fs/seq_file.c
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@@ -443,6 +443,20 @@ int seq_dentry(struct seq_file *m, struct dentry *dentry, char *esc)
return -1;
}
int seq_bitmap(struct seq_file *m, unsigned long *bits, unsigned int nr_bits)
{
size_t len = bitmap_scnprintf_len(nr_bits);
if (m->count + len < m->size) {
bitmap_scnprintf(m->buf + m->count, m->size - m->count,
bits, nr_bits);
m->count += len;
return 0;
}
m->count = m->size;
return -1;
}
static void *single_start(struct seq_file *p, loff_t *pos)
{
return NULL + (*pos == 0);