[PATCH] seq_file: make seq_lseek accept SEEK_END

[Alexey Dobriyan <adobriyan@parallels.com>]

Apologies for delay, such simple thing should have been sent long ago.
Joakim, please, confirm.
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[PATCH] seq_file: make seq_lseek accept SEEK_END

and pretend seq_files have zero length. This should be enough
to fix busybox start-stop-daemon:
http://marc.info/?t=120836691600002&r=1&w=2

It does xlseek(fd, 0, SEEK_END) to estimate amount of memory to malloc
but satisfied with 0. Sudden -EINVAL from lseek(2) breaks it.

X-Introduced-By: f16278c679aa72e28288435b313ba2d4494d6be5
Signed-off-by: Alexey Dobriyan <adobriyan@parallels.com>
---

 fs/seq_file.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -254,6 +254,8 @@ loff_t seq_lseek(struct file *file, loff_t offset, int origin)
 	switch (origin) {
 		case 1:
 			offset += file->f_pos;
+		case 2:
+			/* pretend it's zero length */
 		case 0:
 			if (offset < 0)
 				break;