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authorAlexey Dobriyan <adobriyan@gmail.com>2008-08-12 15:09:02 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-08-12 16:07:30 -0700
commit50ac2d694f2dd1658341cf97bcf2ffb836d772cb (patch)
treec4466ecb7c5211ee9423380783f00027411d5d5a
parentdd763460eb628b57814251a15a39f8d75c044d76 (diff)
downloadconfigs-50ac2d694f2dd1658341cf97bcf2ffb836d772cb.tar.gz
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>
-rw-r--r--fs/seq_file.c14
-rw-r--r--include/linux/bitmap.h1
-rw-r--r--include/linux/seq_file.h12
-rw-r--r--lib/bitmap.c11
4 files changed, 38 insertions, 0 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 3f54dbd6c49..5d54205e486 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -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);
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 1abfe664c44..89781fd4885 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -110,6 +110,7 @@ extern int __bitmap_weight(const unsigned long *bitmap, int bits);
extern int bitmap_scnprintf(char *buf, unsigned int len,
const unsigned long *src, int nbits);
+extern int bitmap_scnprintf_len(unsigned int nr_bits);
extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
unsigned long *dst, int nbits);
extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index a66304a0995..a1783b229ef 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -4,6 +4,8 @@
#include <linux/types.h>
#include <linux/string.h>
#include <linux/mutex.h>
+#include <linux/cpumask.h>
+#include <linux/nodemask.h>
struct seq_operations;
struct file;
@@ -47,6 +49,16 @@ int seq_path(struct seq_file *, struct path *, char *);
int seq_dentry(struct seq_file *, struct dentry *, char *);
int seq_path_root(struct seq_file *m, struct path *path, struct path *root,
char *esc);
+int seq_bitmap(struct seq_file *m, unsigned long *bits, unsigned int nr_bits);
+static inline int seq_cpumask(struct seq_file *m, cpumask_t *mask)
+{
+ return seq_bitmap(m, mask->bits, NR_CPUS);
+}
+
+static inline int seq_nodemask(struct seq_file *m, nodemask_t *mask)
+{
+ return seq_bitmap(m, mask->bits, MAX_NUMNODES);
+}
int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
int single_release(struct inode *, struct file *);
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 482df94ea21..06fb57c86de 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -316,6 +316,17 @@ 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.
* @buflen: buffer size in bytes. If string is smaller than this