From 7be73fa1c1b0b6aaf15d590320f2c5c1108cb87a Mon Sep 17 00:00:00 2001
From: Nathan Chancellor <natechancellor@gmail.com>
Date: Thu, 7 Mar 2019 16:48:11 -0800
Subject: [PATCH 1/4] xfs: Zero initialize highstale and lowstale in
xfs_dir2_leafn_add
When building with -Wsometimes-uninitialized, Clang warns:
fs/xfs/libxfs/xfs_dir2_node.c:481:6: warning: variable 'lowstale' is
used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
fs/xfs/libxfs/xfs_dir2_node.c:481:6: warning: variable 'highstale' is
used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
While it isn't technically wrong, it isn't a problem in practice because
highstale and lowstale are only initialized in xfs_dir2_leafn_add when
compact is not zero then they are passed to xfs_dir3_leaf_find_entry,
where they are initialized before use when compact is zero. Regardless,
it's better not to be passing around uninitialized stack memory so zero
initialize these variables, which silences this warning.
Link: https://github.com/ClangBuiltLinux/linux/issues/393
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/libxfs/xfs_dir2_node.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/xfs/libxfs/xfs_dir2_node.c b/fs/xfs/libxfs/xfs_dir2_node.c
index 3b03703c5c3d..de46f26c5292 100644
--- a/fs/xfs/libxfs/xfs_dir2_node.c
+++ b/fs/xfs/libxfs/xfs_dir2_node.c
@@ -444,6 +444,8 @@ xfs_dir2_leafn_add(
dp = args->dp;
leaf = bp->b_addr;
+ highstale = 0;
+ lowstale = 0;
dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
ents = dp->d_ops->leaf_ents_p(leaf);
From 79622c7ce6879c25ce121ee0db91c0ac4c7b137c Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Thu, 7 Mar 2019 16:50:11 -0800
Subject: [PATCH 2/4] xfs: clean up xfs_dir2_leafn_add
Remove typedefs and consolidate local variable initialization.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---
fs/xfs/libxfs/xfs_dir2_node.c | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_dir2_node.c b/fs/xfs/libxfs/xfs_dir2_node.c
index de46f26c5292..16731d2d684b 100644
--- a/fs/xfs/libxfs/xfs_dir2_node.c
+++ b/fs/xfs/libxfs/xfs_dir2_node.c
@@ -426,26 +426,22 @@ xfs_dir2_leaf_to_node(
static int /* error */
xfs_dir2_leafn_add(
struct xfs_buf *bp, /* leaf buffer */
- xfs_da_args_t *args, /* operation arguments */
+ struct xfs_da_args *args, /* operation arguments */
int index) /* insertion pt for new entry */
{
+ struct xfs_dir3_icleaf_hdr leafhdr;
+ struct xfs_inode *dp = args->dp;
+ struct xfs_dir2_leaf *leaf = bp->b_addr;
+ struct xfs_dir2_leaf_entry *lep;
+ struct xfs_dir2_leaf_entry *ents;
int compact; /* compacting stale leaves */
- xfs_inode_t *dp; /* incore directory inode */
- int highstale; /* next stale entry */
- xfs_dir2_leaf_t *leaf; /* leaf structure */
- xfs_dir2_leaf_entry_t *lep; /* leaf entry */
+ int highstale = 0; /* next stale entry */
int lfloghigh; /* high leaf entry logging */
int lfloglow; /* low leaf entry logging */
- int lowstale; /* previous stale entry */
- struct xfs_dir3_icleaf_hdr leafhdr;
- struct xfs_dir2_leaf_entry *ents;
+ int lowstale = 0; /* previous stale entry */
trace_xfs_dir2_leafn_add(args, index);
- dp = args->dp;
- leaf = bp->b_addr;
- highstale = 0;
- lowstale = 0;
dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
ents = dp->d_ops->leaf_ents_p(leaf);
From f51fac68926235ef5bc482eb759d2c60b86fa358 Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Sun, 10 Mar 2019 11:41:31 -0700
Subject: [PATCH 3/4] xfs: zero initialize highstale and lowstale in
xfs_dir2_leaf_addname
Smatch complains about the following:
fs/xfs/libxfs/xfs_dir2_leaf.c:848 xfs_dir2_leaf_addname() error:
uninitialized symbol 'lowstale'.
fs/xfs/libxfs/xfs_dir2_leaf.c:849 xfs_dir2_leaf_addname() error:
uninitialized symbol 'highstale'.
I don't think there's any incorrect behavior associated with the
uninitialized variable, but as the author of the previous zero-init
patch points out, it's best not to be passing around pointers to
uninitialized stack areas.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
---
fs/xfs/libxfs/xfs_dir2_leaf.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_dir2_leaf.c b/fs/xfs/libxfs/xfs_dir2_leaf.c
index 9a3767818c50..2abf945e5844 100644
--- a/fs/xfs/libxfs/xfs_dir2_leaf.c
+++ b/fs/xfs/libxfs/xfs_dir2_leaf.c
@@ -574,7 +574,7 @@ xfs_dir2_leaf_addname(
xfs_dir2_data_unused_t *dup; /* data unused entry */
int error; /* error return value */
int grown; /* allocated new data block */
- int highstale; /* index of next stale leaf */
+ int highstale = 0; /* index of next stale leaf */
int i; /* temporary, index */
int index; /* leaf table position */
struct xfs_buf *lbp; /* leaf's buffer */
@@ -583,7 +583,7 @@ xfs_dir2_leaf_addname(
xfs_dir2_leaf_entry_t *lep; /* leaf entry table pointer */
int lfloglow; /* low leaf logging index */
int lfloghigh; /* high leaf logging index */
- int lowstale; /* index of prev stale leaf */
+ int lowstale = 0; /* index of prev stale leaf */
xfs_dir2_leaf_tail_t *ltp; /* leaf tail pointer */
int needbytes; /* leaf block bytes needed */
int needlog; /* need to log data header */
From 6ef50fe9afae63d11220f3f66b5f4c75d09c8bf0 Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Sun, 10 Mar 2019 11:46:28 -0700
Subject: [PATCH 4/4] xfs: clean up xfs_dir2_leaf_addname
Remove typedefs and consolidate local variable initialization.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
---
fs/xfs/libxfs/xfs_dir2_leaf.c | 33 +++++++++++++++------------------
1 file changed, 15 insertions(+), 18 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_dir2_leaf.c b/fs/xfs/libxfs/xfs_dir2_leaf.c
index 2abf945e5844..9c2a0a13ed61 100644
--- a/fs/xfs/libxfs/xfs_dir2_leaf.c
+++ b/fs/xfs/libxfs/xfs_dir2_leaf.c
@@ -563,43 +563,40 @@ xfs_dir3_leaf_find_entry(
*/
int /* error */
xfs_dir2_leaf_addname(
- xfs_da_args_t *args) /* operation arguments */
+ struct xfs_da_args *args) /* operation arguments */
{
+ struct xfs_dir3_icleaf_hdr leafhdr;
+ struct xfs_trans *tp = args->trans;
__be16 *bestsp; /* freespace table in leaf */
- int compact; /* need to compact leaves */
- xfs_dir2_data_hdr_t *hdr; /* data block header */
+ __be16 *tagp; /* end of data entry */
struct xfs_buf *dbp; /* data block buffer */
- xfs_dir2_data_entry_t *dep; /* data block entry */
- xfs_inode_t *dp; /* incore directory inode */
- xfs_dir2_data_unused_t *dup; /* data unused entry */
+ struct xfs_buf *lbp; /* leaf's buffer */
+ struct xfs_dir2_leaf *leaf; /* leaf structure */
+ struct xfs_inode *dp = args->dp; /* incore directory inode */
+ struct xfs_dir2_data_hdr *hdr; /* data block header */
+ struct xfs_dir2_data_entry *dep; /* data block entry */
+ struct xfs_dir2_leaf_entry *lep; /* leaf entry table pointer */
+ struct xfs_dir2_leaf_entry *ents;
+ struct xfs_dir2_data_unused *dup; /* data unused entry */
+ struct xfs_dir2_leaf_tail *ltp; /* leaf tail pointer */
+ struct xfs_dir2_data_free *bf; /* bestfree table */
+ int compact; /* need to compact leaves */
int error; /* error return value */
int grown; /* allocated new data block */
int highstale = 0; /* index of next stale leaf */
int i; /* temporary, index */
int index; /* leaf table position */
- struct xfs_buf *lbp; /* leaf's buffer */
- xfs_dir2_leaf_t *leaf; /* leaf structure */
int length; /* length of new entry */
- xfs_dir2_leaf_entry_t *lep; /* leaf entry table pointer */
int lfloglow; /* low leaf logging index */
int lfloghigh; /* high leaf logging index */
int lowstale = 0; /* index of prev stale leaf */
- xfs_dir2_leaf_tail_t *ltp; /* leaf tail pointer */
int needbytes; /* leaf block bytes needed */
int needlog; /* need to log data header */
int needscan; /* need to rescan data free */
- __be16 *tagp; /* end of data entry */
- xfs_trans_t *tp; /* transaction pointer */
xfs_dir2_db_t use_block; /* data block number */
- struct xfs_dir2_data_free *bf; /* bestfree table */
- struct xfs_dir2_leaf_entry *ents;
- struct xfs_dir3_icleaf_hdr leafhdr;
trace_xfs_dir2_leaf_addname(args);
- dp = args->dp;
- tp = args->trans;
-
error = xfs_dir3_leaf_read(tp, dp, args->geo->leafblk, -1, &lbp);
if (error)
return error;