[PATCH] xfsprogs: mkfs: make strict check on -ialign option

[Wengang Wang <wen.gang.wang@xxxxxxxxxx>]

Though it's clearly said in mkfs.xfs man page that for -ialign option only 1 or
0 are valid values, I would like to make a strict check on it in code.

If a user specified -ialign=y(but he meant -ialign=1 actually), mkfs treats "y"
as "0"(simply by atoi()) thus acts wrongly without complaint. I think we'd 
better
prevent that from happening, so I made the patch. The patch fails the operation
on values for -ialign option, like "yes", "no", "y", "n".

Signed-off-by: Wengang Wang <wen.gang.wang@xxxxxxxxxx>
---
 mkfs/xfs_mkfs.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 2d09e36..d7e9eb3 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -1180,14 +1180,17 @@ main(
                        p = optarg;
                        while (*p != '\0') {
                                char    *value;
+                               int len;
 
                                switch (getsubopt(&p, (constpp)iopts, &value)) {
                                case I_ALIGN:
                                        if (!value)
                                                value = "1";
-                                       iaflag = atoi(value);
-                                       if (iaflag < 0 || iaflag > 1)
+                                       len = strlen(value);
+                                       if (len != 1 || value[0] < '0' ||
+                                           value[0] > '1')
                                                illegal(value, "i align");
+                                       iaflag = value[0] - '0';
                                        break;
                                case I_LOG:
                                        if (!value)
-- 
1.6.6.1