staging: lustre: fix 'NULL pointer dereference' errors

Fix 'NULL pointer dereference' defects found by Coverity version
6.5.0:
Dereference after null check (FORWARD_NULL)
For instance, Passing null pointer to a function which dereferences
it.
Dereference before null check (REVERSE_INULL)
Null-checking variable suggests that it may be null, but it has
already been dereferenced on all paths leading to the check.
Dereference null return value (NULL_RETURNS)

Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Signed-off-by: James Nunez <james.a.nunez@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3042
Reviewed-on: http://review.whamcloud.com/5868
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/lustre/lustre/llite/dir.c b/drivers/staging/lustre/lustre/llite/dir.c
index 955acd4..7736139 100644 (file)
--- a/drivers/staging/lustre/lustre/llite/dir.c
+++ b/drivers/staging/lustre/lustre/llite/dir.c
@@ -611,15 +611,16 @@ static int ll_readdir(struct file *filp, struct dir_context *ctx)
        struct inode            *inode  = file_inode(filp);
        struct ll_file_data     *lfd    = LUSTRE_FPRIVATE(filp);
        struct ll_sb_info       *sbi    = ll_i2sbi(inode);
+       __u64 pos = lfd ? lfd->lfd_pos : 0;
        int                     hash64  = sbi->ll_flags & LL_SBI_64BIT_HASH;
        int                     api32   = ll_need_32bit_api(sbi);
        int                     rc;
 
        CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p) pos %lu/%llu 32bit_api %d\n",
               inode->i_ino, inode->i_generation,
-              inode, (unsigned long)lfd->lfd_pos, i_size_read(inode), api32);
+              inode, (unsigned long)pos, i_size_read(inode), api32);
 
-       if (lfd->lfd_pos == MDS_DIR_END_OFF) {
+       if (pos == MDS_DIR_END_OFF) {
                /*
                 * end-of-file.
                 */
@@ -627,9 +628,10 @@ static int ll_readdir(struct file *filp, struct dir_context *ctx)
                goto out;
        }
 
-       ctx->pos = lfd->lfd_pos;
+       ctx->pos = pos;
        rc = ll_dir_read(inode, ctx);
-       lfd->lfd_pos = ctx->pos;
+       if (lfd)
+               lfd->lfd_pos = ctx->pos;
        if (ctx->pos == MDS_DIR_END_OFF) {
                if (api32)
                        ctx->pos = LL_DIR_END_OFF_32BIT;

diff --git a/drivers/staging/lustre/lustre/lov/lov_io.c b/drivers/staging/lustre/lustre/lov/lov_io.c
index f443778..da4784b 100644 (file)
--- a/drivers/staging/lustre/lustre/lov/lov_io.c
+++ b/drivers/staging/lustre/lustre/lov/lov_io.c
@@ -277,10 +277,11 @@ struct lov_io_sub *lov_page_subio(const struct lu_env *env, struct lov_io *lio,
 static int lov_io_subio_init(const struct lu_env *env, struct lov_io *lio,
                             struct cl_io *io)
 {
-       struct lov_stripe_md *lsm = lio->lis_object->lo_lsm;
+       struct lov_stripe_md *lsm;
        int result;
 
        LASSERT(lio->lis_object);
+       lsm = lio->lis_object->lo_lsm;
 
        /*
         * Need to be optimized, we can't afford to allocate a piece of memory