EX-7812 llite: use CIT_MISC in check_compression

ll_mmap_check_compression uses a CIT_FAULT io type and
initializes it with cl_io_rw_init.  This doesn't
initialize the IO correctly and this sometimes results
in the following crash during io_fini, because the ft_page
pointer is initialized to something else by cl_io_rw_init:

[ 1512.276302] BUG: unable to handle kernel NULL pointer dereference at 000000000000004a
[ 1512.280778] RIP: 0010:cl_pagevec_put+0x9f/0x3a0 [obdclass]
[ 1512.288693]  vvp_io_fault_fini+0x21/0x40 [lustre]
[ 1512.289294]  cl_io_fini+0x7a/0x230 [obdclass]
[ 1512.289876]  ll_mmap_check_compression+0x403/0x540 [lustre]

Fixes: 95df962a92 ("EX-6265 llite: disable mmap on compressed files"

Signed-off-by: Patrick Farrell <pfarrell@whamcloud.com>
Change-Id: Ib1f270f071370d6c045bb9d799ab5b7b41a6c6be
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/51553
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>

diff --git a/lustre/llite/llite_mmap.c b/lustre/llite/llite_mmap.c
index 096c589..22fcf44 100644 (file)
--- a/lustre/llite/llite_mmap.c
+++ b/lustre/llite/llite_mmap.c
@@ -607,8 +607,6 @@ int ll_mmap_check_compression(struct file *file, loff_t off)
 {
        struct inode *inode = file_inode(file);
        struct ll_inode_info *lli = ll_i2info(inode);
-       struct vvp_io_args *args;
-       struct kiocb kiocb;
        struct lu_env *env;
        struct cl_io *io;
        __u16 refcheck;
@@ -630,38 +628,19 @@ int ll_mmap_check_compression(struct file *file, loff_t off)
        /* XXX: ignore PCC for a while */
        if (lli->lli_pcc_inode || lli->lli_pcc_generation)
                RETURN(0);
-       init_sync_kiocb(&kiocb, file);
-       kiocb.ki_pos = off;
-#ifdef HAVE_KIOCB_KI_LEFT
-       kiocb.ki_left = 4096;
-#elif defined(HAVE_KI_NBYTES)
-       kiocb.ki_nbytes = 4096;
-#endif
-
-       env = cl_env_get(&refcheck);
-       if (IS_ERR(env))
-               RETURN(PTR_ERR(env));
 
-       io = vvp_env_thread_io(env);
-
-       args = ll_env_args(env);
-       args->u.normal.via_iter = NULL;
-       args->u.normal.via_iocb = &kiocb;
-       ll_io_init(io, file, CIT_FAULT, args);
-
-       io->ci_dio_aio = NULL;
-       io->ci_dio_lock = 0;
-       io->ci_ndelay_tried = 0;
-       io->ci_parallel_dio = false;
+       rc = cl_io_get(inode, &env, &io, &refcheck);
+       if (rc <= 0)
+               RETURN(rc);
 
-       rc = cl_io_rw_init(env, io, CIT_FAULT, off, 4096);
+       rc = cl_io_init(env, io, CIT_MISC, lli->lli_clob);
        if (rc == 0) {
                if (io->ci_compressed_io)
                        rc = -EOPNOTSUPP;
        } else if (rc == 1 || rc == -ENODATA) {
                rc = 0;
        } else {
-               CERROR("%s: "DFID" cl_io_rw_init() failed: rc = %d\n",
+               CERROR("%s: "DFID" cl_io_init() failed: rc = %d\n",
                       ll_i2sbi(inode)->ll_fsname, PFID(&lli->lli_fid), rc);
        }
 

diff --git a/lustre/obdclass/cl_io.c b/lustre/obdclass/cl_io.c
index 6e16645..aae858e 100644 (file)
--- a/lustre/obdclass/cl_io.c
+++ b/lustre/obdclass/cl_io.c
@@ -208,8 +208,8 @@ EXPORT_SYMBOL(cl_io_init);
 int cl_io_rw_init(const struct lu_env *env, struct cl_io *io,
                  enum cl_io_type iot, loff_t pos, size_t count)
 {
-       LINVRNT(iot == CIT_READ || iot == CIT_WRITE);
-       LINVRNT(io->ci_obj != NULL);
+       LASSERT(iot == CIT_READ || iot == CIT_WRITE);
+       LASSERT(io->ci_obj != NULL);
        ENTRY;
 
        LU_OBJECT_HEADER(D_VFSTRACE, env, &io->ci_obj->co_lu,