From 50ac2d694f2dd1658341cf97bcf2ffb836d772cb Mon Sep 17 00:00:00 2001
From: Alexey Dobriyan <adobriyan@gmail.com>
Date: Tue, 12 Aug 2008 15:09:02 -0700
Subject: seq_file: add seq_cpumask(), seq_nodemask()
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>
---
lib/bitmap.c | 11 +++++++++++
1 file changed, 11 insertions(+)
(limited to 'lib/bitmap.c')
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 482df94ea21..06fb57c86de 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -315,6 +315,17 @@ int bitmap_scnprintf(char *buf, unsigned int buflen,
}
EXPORT_SYMBOL(bitmap_scnprintf);
+/**
+ * bitmap_scnprintf_len - return buffer length needed to convert
+ * bitmap to an ASCII hex string
+ * @nr_bits: number of bits to be converted
+ */
+int bitmap_scnprintf_len(unsigned int nr_bits)
+{
+ unsigned int nr_nibbles = ALIGN(nr_bits, 4) / 4;
+ return nr_nibbles + ALIGN(nr_nibbles, CHUNKSZ / 4) / (CHUNKSZ / 4) - 1;
+}
+
/**
* __bitmap_parse - convert an ASCII hex string into a bitmap.
* @buf: pointer to buffer containing string.
--
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