Following bug was uncovered by compiling with '-W' flag:
CC [M] fs/afs/write.o
fs/afs/write.c: In function ‘afs_write_back_from_locked_page’:
fs/afs/write.c:398: warning: comparison of unsigned expression >= 0 is always true
Loop variable 'n' is unsigned, so wraps around happily as far as I can
see. Trival fix attached (compile tested only).
Signed-Off-By: Mika Kukkonen <[email protected]>
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 83ff292..4bca263 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -395,8 +395,9 @@ static int afs_write_back_from_locked_page(struct afs_writeback *wb,
if (n == 0)
goto no_more;
if (pages[0]->index != start) {
- for (n--; n >= 0; n--)
+ for (n--; n > 0; n--)
put_page(pages[n]);
+ put_page(pages[0]);
goto no_more;
}
How about the attached instead?
David
---
AFS: Fix interminable loop in afs_write_back_from_locked_page()
From: Mika Kukkonen <[email protected]>
Following bug was uncovered by compiling with '-W' flag:
CC [M] fs/afs/write.o
fs/afs/write.c: In function ‘afs_write_back_from_locked_page’:
fs/afs/write.c:398: warning: comparison of unsigned expression >= 0 is always true
Loop variable 'n' is unsigned, so wraps around happily as far as I can
see. Trival fix attached (compile tested only).
Signed-Off-By: Mika Kukkonen <[email protected]>
Signed-off-by: David Howells <[email protected]>
---
fs/afs/write.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 67ae4db..c26d5e8 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -395,8 +395,10 @@ static int afs_write_back_from_locked_page(struct afs_writeback *wb,
if (n == 0)
goto no_more;
if (pages[0]->index != start) {
- for (n--; n >= 0; n--)
- put_page(pages[n]);
+ do {
+ put_page(pages[--n]);
+ } while (n > 0);
+ put_page(pages[0]);
goto no_more;
}
David Howells <[email protected]> wrote:
> How about the attached instead?
Blech. How about this instead? I forgot to remove the extra put_page() you
added.
David
---
AFS: Fix interminable loop in afs_write_back_from_locked_page()
From: Mika Kukkonen <[email protected]>
Following bug was uncovered by compiling with '-W' flag:
CC [M] fs/afs/write.o
fs/afs/write.c: In function ‘afs_write_back_from_locked_page’:
fs/afs/write.c:398: warning: comparison of unsigned expression >= 0 is always true
Loop variable 'n' is unsigned, so wraps around happily as far as I can
see. Trival fix attached (compile tested only).
Signed-Off-By: Mika Kukkonen <[email protected]>
Signed-off-by: David Howells <[email protected]>
---
fs/afs/write.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 67ae4db..28f3751 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -395,8 +395,9 @@ static int afs_write_back_from_locked_page(struct afs_writeback *wb,
if (n == 0)
goto no_more;
if (pages[0]->index != start) {
- for (n--; n >= 0; n--)
- put_page(pages[n]);
+ do {
+ put_page(pages[--n]);
+ } while (n > 0);
goto no_more;
}