aboutsummaryrefslogtreecommitdiff
path: root/fs/seq_file.c
diff options
context:
space:
mode:
authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2012-03-23 15:02:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-23 16:58:42 -0700
commite075f59152890ffd7e3d704afc997dd686c8a781 (patch)
tree94dbf5eda32d7dea9821ca308c4317e75756f7bd /fs/seq_file.c
parent1b26c9b334044cff6d1d2698f2be41bc7d9a0864 (diff)
downloadlinux-stericsson-e075f59152890ffd7e3d704afc997dd686c8a781.tar.gz
seq_file: add seq_set_overflow(), seq_overflow()
It is undocumented but a seq_file's overflow state is indicated by m->count == m->size. Add seq_set_overflow() and seq_overflow() to set/check overflow status explicitly. Based on an idea from Eric Dumazet. [akpm@linux-foundation.org: tweak code comment] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Eric Dumazet <eric.dumazet@gmail.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>
Diffstat (limited to 'fs/seq_file.c')
-rw-r--r--fs/seq_file.c36
1 files changed, 26 insertions, 10 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 55c293f7024d..46cfb067fc3a 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -13,6 +13,22 @@
#include <asm/uaccess.h>
#include <asm/page.h>
+
+/*
+ * seq_files have a buffer which can may overflow. When this happens a larger
+ * buffer is reallocated and all the data will be printed again.
+ * The overflow state is true when m->count == m->size.
+ */
+static bool seq_overflow(struct seq_file *m)
+{
+ return m->count == m->size;
+}
+
+static void seq_set_overflow(struct seq_file *m)
+{
+ m->count = m->size;
+}
+
/**
* seq_open - initialize sequential file
* @file: file we initialize
@@ -92,7 +108,7 @@ static int traverse(struct seq_file *m, loff_t offset)
error = 0;
m->count = 0;
}
- if (m->count == m->size)
+ if (seq_overflow(m))
goto Eoverflow;
if (pos + m->count > offset) {
m->from = offset - pos;
@@ -234,7 +250,7 @@ Fill:
break;
}
err = m->op->show(m, p);
- if (m->count == m->size || err) {
+ if (seq_overflow(m) || err) {
m->count = offs;
if (likely(err <= 0))
break;
@@ -361,7 +377,7 @@ int seq_escape(struct seq_file *m, const char *s, const char *esc)
*p++ = '0' + (c & 07);
continue;
}
- m->count = m->size;
+ seq_set_overflow(m);
return -1;
}
m->count = p - m->buf;
@@ -383,7 +399,7 @@ int seq_printf(struct seq_file *m, const char *f, ...)
return 0;
}
}
- m->count = m->size;
+ seq_set_overflow(m);
return -1;
}
EXPORT_SYMBOL(seq_printf);
@@ -512,7 +528,7 @@ int seq_bitmap(struct seq_file *m, const unsigned long *bits,
return 0;
}
}
- m->count = m->size;
+ seq_set_overflow(m);
return -1;
}
EXPORT_SYMBOL(seq_bitmap);
@@ -528,7 +544,7 @@ int seq_bitmap_list(struct seq_file *m, const unsigned long *bits,
return 0;
}
}
- m->count = m->size;
+ seq_set_overflow(m);
return -1;
}
EXPORT_SYMBOL(seq_bitmap_list);
@@ -639,7 +655,7 @@ int seq_puts(struct seq_file *m, const char *s)
m->count += len;
return 0;
}
- m->count = m->size;
+ seq_set_overflow(m);
return -1;
}
EXPORT_SYMBOL(seq_puts);
@@ -673,7 +689,7 @@ int seq_put_decimal_ull(struct seq_file *m, char delimiter,
m->count += len;
return 0;
overflow:
- m->count = m->size;
+ seq_set_overflow(m);
return -1;
}
EXPORT_SYMBOL(seq_put_decimal_ull);
@@ -683,7 +699,7 @@ int seq_put_decimal_ll(struct seq_file *m, char delimiter,
{
if (num < 0) {
if (m->count + 3 >= m->size) {
- m->count = m->size;
+ seq_set_overflow(m);
return -1;
}
if (delimiter)
@@ -711,7 +727,7 @@ int seq_write(struct seq_file *seq, const void *data, size_t len)
seq->count += len;
return 0;
}
- seq->count = seq->size;
+ seq_set_overflow(seq);
return -1;
}
EXPORT_SYMBOL(seq_write);