From 50ac2d694f2dd1658341cf97bcf2ffb836d772cb Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Tue, 12 Aug 2008 15:09:02 -0700 Subject: [PATCH] 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 Reviewed-by: Paul Jackson Cc: Mike Travis Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/seq_file.c | 14 ++++++++++++++ include/linux/bitmap.h | 1 + include/linux/seq_file.h | 12 ++++++++++++ lib/bitmap.c | 11 +++++++++++ 4 files changed, 38 insertions(+) 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 #include #include +#include +#include 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 @@ -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. -- 2.41.1