EX-6265 llite: allow mmap reads of compressed files

mmap reads of compressed files work, so we should only
block writes.

We cannot block the actual fault operations because that
will cause the application to get a SIGBUS, so we check
the file open mode when we go to create the memory mapping.

Signed-off-by: Patrick Farrell <pfarrell@whamcloud.com>
Change-Id: I636f398fd247ddcd153f94bf8116440540e8469c
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/51506
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Qian Yingjin <qian@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>

diff --git a/lustre/llite/llite_mmap.c b/lustre/llite/llite_mmap.c
index 11d0570..096c589 100644 (file)
--- a/lustre/llite/llite_mmap.c
+++ b/lustre/llite/llite_mmap.c
@@ -603,7 +603,7 @@ static const struct vm_operations_struct ll_file_vm_ops = {
        .close                  = ll_vm_close,
 };
 
-int ll_mmap_check_compression(struct file *file, unsigned long off)
+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);
@@ -615,9 +615,14 @@ int ll_mmap_check_compression(struct file *file, unsigned long off)
        int rc = 0;
        __u32 gen;
 
+       /* mmap reads of compressed files are supported */
+       if ((file->f_flags & O_ACCMODE) == O_RDONLY)
+               RETURN(0);
+
        rc = ll_layout_refresh(inode, &gen);
        if (rc) {
-               CERROR("can't refresh layout: rc=%d\n", rc);
+               CERROR("%s: "DFID" cannot refresh layout: rc = %d\n",
+                      ll_i2sbi(inode)->ll_fsname, PFID(&lli->lli_fid), rc);
                RETURN(rc);
        }
        if (ll_layout_version_get(lli) == CL_LAYOUT_GEN_EMPTY)
@@ -655,8 +660,10 @@ int ll_mmap_check_compression(struct file *file, unsigned long off)
                        rc = -EOPNOTSUPP;
        } else if (rc == 1 || rc == -ENODATA) {
                rc = 0;
-       } else
-               CDEBUG(D_ERROR, "rc=%d\n", rc);
+       } else {
+               CERROR("%s: "DFID" cl_io_rw_init() failed: rc = %d\n",
+                      ll_i2sbi(inode)->ll_fsname, PFID(&lli->lli_fid), rc);
+       }
 
        cl_io_fini(env, io);
 
@@ -681,7 +688,7 @@ int ll_file_mmap(struct file *file, struct vm_area_struct * vma)
        if (ll_file_nolock(file))
                RETURN(-EOPNOTSUPP);
 
-       rc = ll_mmap_check_compression(file, vma->vm_pgoff << PAGE_SHIFT);
+       rc = ll_mmap_check_compression(file, (loff_t)vma->vm_pgoff<<PAGE_SHIFT);
        if (rc)
                RETURN(rc);
 

diff --git a/lustre/tests/multiop.c b/lustre/tests/multiop.c
index 70b61d8..09ff6e1 100644 (file)
--- a/lustre/tests/multiop.c
+++ b/lustre/tests/multiop.c
@@ -516,20 +516,39 @@ int main(int argc, char **argv)
                        }
                        break;
                case 'M':
+               {
+                       int mmap_mode = 0;
+                       int fd_flags;
+
                        if (st.st_size == 0) {
                                fprintf(stderr,
                                        "mmap without preceeding stat, or on zero length file.\n");
                                exit(-1);
                        }
+
+                       /* match mmap mode to file open mode */
+                       fd_flags = fcntl(fd, F_GETFL);
+                       if (fd_flags < 0) {
+                               fprintf(stderr,
+                                       "unable to get file flags for mmap\n");
+                               exit (-1);
+                       }
+                       if (fd_flags & O_RDONLY || fd_flags & O_RDWR)
+                               mmap_mode |= PROT_READ;
+
+                       if (fd_flags & O_WRONLY || fd_flags & O_RDWR)
+                               mmap_mode |= PROT_WRITE;
+
                        mmap_len = st.st_size;
-                       mmap_ptr = mmap(NULL, mmap_len, PROT_WRITE | PROT_READ,
-                                       MAP_SHARED, fd, 0);
+                       mmap_ptr = mmap(NULL, mmap_len, mmap_mode, MAP_SHARED,
+                                       fd, 0);
                        if (mmap_ptr == MAP_FAILED) {
                                save_errno = errno;
                                perror("mmap");
                                exit(save_errno);
                        }
                        break;
+               }
                case 'n':
                        oldpath = POP_ARG();
                        if (!oldpath)

diff --git a/lustre/tests/sanity.sh b/lustre/tests/sanity.sh
index 321a4ca..5814088 100755 (executable)
--- a/lustre/tests/sanity.sh
+++ b/lustre/tests/sanity.sh
@@ -27778,44 +27778,46 @@ test_460d() {
 run_test 460d "Check encrypt pools output"
 
 test_460e() {
-       (( MDS1_VERSION >= $(version_code 2.14.0.85) )) ||
-               skip "Need MDS version at least 2.14.0.85"
+       (( MDS1_VERSION >= $(version_code 2.14.0.91) )) ||
+               skip "Need MDS version at least 2.14.0.91"
 
        local tf=$DIR/$tfile
 
-       stack_trap "rm -Rf $DIR/$tfile; disable_compression"
+       stack_trap "rm -f $tf; disable_compression"
        enable_compression
 
        $LFS setstripe -E -1 -Z lz4:5 --compress-chunk=64 $tf ||
                error "set a compress component in $tf failed"
 
-       dd if=/dev/zero of=$tf bs=32k count=5 ||
-               error "dd to $stored failed"
+       dd if=/dev/zero of=$tf bs=32k count=5 || error "dd to $stored failed"
 
        sync; echo 3 > /proc/sys/vm/drop_caches
 
        $LFS getstripe $tf
-       $LFS getstripe $tf | grep lcme_flags.*compress ||
+       $LFS getstripe $tf | grep -q lcme_flags.*compress ||
                error "no compressed component"
 
-       $MULTIOP $tf OSMc && error "mmap must be disabled"
+       $MULTIOP $tf OSMc &&
+               error "(0) writeable mmap of compressed files should not work"
+       $MULTIOP $tf oSMc ||
+               error "(1) readonly mmap of compressed files should work"
 
        rm -f $tf
-       dd if=/dev/zero of=$tf bs=32k count=5 ||
-               error "dd to $stored failed"
-       $MULTIOP $tf OSMc || error "mmap must be disabled"
-
-       return 0
+       dd if=/dev/zero of=$tf bs=32k count=5 || error "dd(2) to $stored failed"
+       $MULTIOP $tf OSMc ||
+               error "(2) writeable mmap of uncompressed files should work"
+       $MULTIOP $tf oSMc ||
+               error "(3) readonly mmap of uncompressed files should work"
 }
 run_test 460e "verify mmap is disabled with compressed files"
 
 test_460f() {
-       (( MDS1_VERSION >= $(version_code 2.14.0.90) )) ||
-               skip "Need MDS version at least 2.14.0.90"
+       (( MDS1_VERSION >= $(version_code 2.14.0.91) )) ||
+               skip "Need MDS version at least 2.14.0.91"
 
        local tf=$DIR/$tfile
 
-       stack_trap "rm -f $DIR/$tfile; disable_compression"
+       stack_trap "rm -f $tf; disable_compression"
        enable_compression
 
        $LFS setstripe -E -1 -Z gzip:3 --compress-chunk=64 $tf ||
@@ -27836,7 +27838,6 @@ test_460f() {
        [[ $offset == 131072 ]] || error "offset $offset != 131072"
        printf "Seeking data from $offset ... "
        lseek_test -d $offset $tf && error "data lseek should fail"
-       rm -f $tf
 
        return 0
 }