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authorPavel Emelianov <xemul@sw.ru>2007-07-11 02:22:26 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-11 02:51:13 +0200
commitbcf67e16251c42302499499b1c50f7d35622f564 (patch)
tree3df64aa83005c0a153acf3a1a0d7a6e6d49dc688
parentsx: switch subven and subid values (diff)
downloadlinux-bcf67e16251c42302499499b1c50f7d35622f564.tar.xz
linux-bcf67e16251c42302499499b1c50f7d35622f564.zip
Make common helpers for seq_files that work with list_heads
Many places in kernel use seq_file API to iterate over a regular list_head. The code for such iteration is identical in all the places, so it's worth introducing a common helpers. This makes code about 300 lines smaller: The first version of this patch made the helper functions static inline in the seq_file.h header. This patch moves them to the fs/seq_file.c as Andrew proposed. The vmlinux .text section sizes are as follows: 2.6.22-rc1-mm1: 0x001794d5 with the previous version: 0x00179505 with this patch: 0x00179135 The config file used was make allnoconfig with the "y" inclusion of all the possible options to make the files modified by the patch compile plus drivers I have on the test node. This patch: Many places in kernel use seq_file API to iterate over a regular list_head. The code for such iteration is identical in all the places, so it's worth introducing a common helpers. Signed-off-by: Pavel Emelianov <xemul@openvz.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/seq_file.c34
-rw-r--r--include/linux/seq_file.h11
2 files changed, 45 insertions, 0 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 0ac22af7afe5..49194a4e6b91 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -447,3 +447,37 @@ int seq_puts(struct seq_file *m, const char *s)
return -1;
}
EXPORT_SYMBOL(seq_puts);
+
+struct list_head *seq_list_start(struct list_head *head, loff_t pos)
+{
+ struct list_head *lh;
+
+ list_for_each(lh, head)
+ if (pos-- == 0)
+ return lh;
+
+ return NULL;
+}
+
+EXPORT_SYMBOL(seq_list_start);
+
+struct list_head *seq_list_start_head(struct list_head *head, loff_t pos)
+{
+ if (!pos)
+ return head;
+
+ return seq_list_start(head, pos - 1);
+}
+
+EXPORT_SYMBOL(seq_list_start_head);
+
+struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos)
+{
+ struct list_head *lh;
+
+ lh = ((struct list_head *)v)->next;
+ ++*ppos;
+ return lh == head ? NULL : lh;
+}
+
+EXPORT_SYMBOL(seq_list_next);
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 3e3cccbb1cac..83783ab0f552 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -50,5 +50,16 @@ int seq_release_private(struct inode *, struct file *);
#define SEQ_START_TOKEN ((void *)1)
+/*
+ * Helpers for iteration over list_head-s in seq_files
+ */
+
+extern struct list_head *seq_list_start(struct list_head *head,
+ loff_t pos);
+extern struct list_head *seq_list_start_head(struct list_head *head,
+ loff_t pos);
+extern struct list_head *seq_list_next(void *v, struct list_head *head,
+ loff_t *ppos);
+
#endif
#endif