open_by_handle: add -s option to sleep and keep files open by handle
[xfstests-dev.git] / src / open_by_handle.c
index 76510ff2aaa77097f2bc31cad4071073b1e16c00..f5be2350e3fdefd447edb419467e812b550ea8fd 100644 (file)
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
 
+/*
+
+usage: open_by_handle [-cludmrwapknhs] [<-i|-o> <handles_file>] <test_dir> [num_files]
+
+Examples:
+
+1. Create test set of of test_dir with N files and try to get their NFS handles:
+
+   open_by_handle -cp <test_dir> [N]
+
+   This is used by new helper _require_exportfs() to check
+   if filesystem supports exportfs
+
+2. Get file handles for existing test set, drop caches and try to
+   open all files by handle:
+
+   open_by_handle -p <test_dir> [N]
+
+3. Get file handles for existing test set and write them to a file:
+
+   open_by_handle -p -o <handles_file> <test_dir> [N]
+
+4. Read file handles from file and open files by handle without
+   dropping caches beforehand. Sleep afterhand to keep files open:
+
+   open_by_handle -nps -i <handles_file> <test_dir> [N]
+
+5. Get file handles for existing test set, write data to files,
+   drop caches, open all files by handle, read and verify written
+   data, write new data to file:
+
+   open_by_handle -rwa <test_dir> [N]
+
+6. Get file handles for existing test set, unlink all test files,
+   remove test_dir, drop caches, try to open all files by handle
+   and expect ESTALE:
+
+   open_by_handle -dp <test_dir> [N]
+
+7. Get file handles for existing test set, keep open file handles for all
+   test files, unlink all test files, drop caches and try to open all files
+   by handle (should work):
+
+   open_by_handle -dk <test_dir> [N]
+
+8. Get file handles for existing test set, rename all test files,
+   drop caches, try to open all files by handle (should work):
+
+   open_by_handle -m <test_dir> [N]
+
+9. Get file handles for existing test set, hardlink all test files,
+   then unlink the original files, drop caches and try to open all
+   files by handle (should work):
+
+   open_by_handle -l <test_dir> [N]
+   open_by_handle -u <test_dir> [N]
+
+   This test is done with 2 invocations of the program, first to
+   hardlink (-l) and then to unlink the originals (-u), because
+   we would like to be able to perform the hardlinks on overlay
+   lower layer and unlink on upper layer.
+
+   NOTE that open_by_handle -u doesn't check if the files are
+   hardlinked, it just assumes that they are.  If they are not
+   then the test will fail, because file handles would be stale.
+*/
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
 #include <errno.h>
 #include <linux/limits.h>
+#include <libgen.h>
 
-#define NUMFILES 1024
+#define MAXFILES 1024
 
 struct handle {
        struct file_handle fh;
        unsigned char fid[MAX_HANDLE_SZ];
-} handle[NUMFILES];
+} handle[MAXFILES], dir_handle;
+
+void usage(void)
+{
+       fprintf(stderr, "usage: open_by_handle [-cludmrwapknhs] [<-i|-o> <handles_file>] <test_dir> [num_files]\n");
+       fprintf(stderr, "\n");
+       fprintf(stderr, "open_by_handle -c <test_dir> [N] - create N test files under test_dir, try to get file handles and exit\n");
+       fprintf(stderr, "open_by_handle    <test_dir> [N] - get file handles of test files, drop caches and try to open by handle\n");
+       fprintf(stderr, "open_by_handle -n <test_dir> [N] - get file handles of test files and try to open by handle without drop caches\n");
+       fprintf(stderr, "open_by_handle -k <test_dir> [N] - get file handles of files that are kept open, drop caches and try to open by handle\n");
+       fprintf(stderr, "open_by_handle -w <test_dir> [N] - write data to test files before open by handle\n");
+       fprintf(stderr, "open_by_handle -r <test_dir> [N] - read data from test files after open by handle and verify written data\n");
+       fprintf(stderr, "open_by_handle -a <test_dir> [N] - write data to test files after open by handle\n");
+       fprintf(stderr, "open_by_handle -l <test_dir> [N] - create hardlinks to test files, drop caches and try to open by handle\n");
+       fprintf(stderr, "open_by_handle -u <test_dir> [N] - unlink (hardlinked) test files, drop caches and try to open by handle\n");
+       fprintf(stderr, "open_by_handle -d <test_dir> [N] - unlink test files and hardlinks, drop caches and try to open by handle\n");
+       fprintf(stderr, "open_by_handle -m <test_dir> [N] - rename test files, drop caches and try to open by handle\n");
+       fprintf(stderr, "open_by_handle -p <test_dir>     - create/delete and try to open by handle also test_dir itself\n");
+       fprintf(stderr, "open_by_handle -i <handles_file> <test_dir> [N] - read test files handles from file and try to open by handle\n");
+       fprintf(stderr, "open_by_handle -o <handles_file> <test_dir> [N] - get file handles of test files and write handles to file\n");
+       fprintf(stderr, "open_by_handle -s <test_dir> [N] - wait in sleep loop after opening files by handle to keep them open\n");
+       exit(EXIT_FAILURE);
+}
 
 int main(int argc, char **argv)
 {
-       int     i;
+       int     i, c;
        int     fd;
-       int     ret;
+       int     ret = 0;
        int     failed = 0;
+       char    dname[PATH_MAX];
        char    fname[PATH_MAX];
+       char    fname2[PATH_MAX];
        char    *test_dir;
+       char    *mount_dir;
        int     mount_fd, mount_id;
+       char    *infile = NULL, *outfile = NULL;
+       int     in_fd = 0, out_fd = 0;
+       int     numfiles = 1;
+       int     create = 0, delete = 0, nlink = 1, move = 0;
+       int     rd = 0, wr = 0, wrafter = 0, parent = 0;
+       int     keepopen = 0, drop_caches = 1, sleep_loop = 0;
 
-       if (argc != 2) {
-               fprintf(stderr, "usage: open_by_handle <test_dir>\n");
-               return EXIT_FAILURE;
+       if (argc < 2)
+               usage();
+
+       while ((c = getopt(argc, argv, "cludmrwapknhi:o:s")) != -1) {
+               switch (c) {
+               case 'c':
+                       create = 1;
+                       break;
+               case 'w':
+                       /* Write data before open_by_handle_at() */
+                       wr = 1;
+                       break;
+               case 'r':
+                       /* Read data after open_by_handle_at() */
+                       rd = 1;
+                       break;
+               case 'a':
+                       /* Write data after open_by_handle_at() */
+                       wrafter = 1;
+                       break;
+               case 'l':
+                       nlink = 2;
+                       break;
+               case 'u':
+                       delete = 1;
+                       nlink = 1;
+                       break;
+               case 'd':
+                       delete = 1;
+                       nlink = 0;
+                       break;
+               case 'm':
+                       move = 1;
+                       break;
+               case 'p':
+                       parent = 1;
+                       break;
+               case 'k':
+                       keepopen = 1;
+                       break;
+               case 'n':
+                       drop_caches = 0;
+                       break;
+               case 'i':
+                       infile = optarg;
+                       in_fd = open(infile, O_RDONLY);
+                       if (in_fd < 0) {
+                               perror(infile);
+                               return EXIT_FAILURE;
+                       }
+                       break;
+               case 'o':
+                       outfile = optarg;
+                       out_fd = creat(outfile, 0644);
+                       if (out_fd < 0) {
+                               perror(outfile);
+                               return EXIT_FAILURE;
+                       }
+                       break;
+               case 's':
+                       sleep_loop = 1;
+                       break;
+               default:
+                       fprintf(stderr, "illegal option '%s'\n", argv[optind]);
+               case 'h':
+                       usage();
+               }
+       }
+        if (optind == argc)
+            usage();
+       test_dir = argv[optind++];
+       if (optind < argc)
+               numfiles = atoi(argv[optind]);
+       if (!numfiles || numfiles > MAXFILES) {
+               fprintf(stderr, "illegal value '%s' for num_files\n", argv[optind]);
+               usage();
+       }
+
+       /*
+        * The way we determine the mount_dir to be used for mount_fd argument
+        * for open_by_handle_at() depends on other command line arguments:
+        *
+        * -p flag usually (see -i below) implies that test_dir is NOT a mount
+        *    point, but a directory inside a mount point that we will create
+        *    and/or encode/decode during the test, so we use test_dir's parent
+        *    for mount_fd. Even when not creatig test_dir, if we would use
+        *    test_dir as mount_fd, then drop_caches will not drop the test_dir
+        *    dcache entry.
+        *
+        * If -p is not specified, we don't have a hint whether test_dir is a
+        *    mount point or not, so we assume the worst case, that it is a
+        *    mount point and therefore, we cannnot use parent as mount_fd,
+        *    because parent may be on a differnt file system.
+        *
+        * -i flag, even with -p flag, implies that test_dir IS a mount point,
+        *    because we are testing open by handle of dir, which may have been
+        *    deleted or renamed and we are not creating nor encoding the
+        *    directory file handle. -i flag is meant to be used for tests
+        *    after encoding file handles and mount cycle the file system. If
+        *    we would require the test to pass in with -ip the test_dir we
+        *    want to decode and not the mount point, that would have populated
+        *    the dentry cache and the use of -ip flag combination would not
+        *    allow testing decode of dir file handle in cold dcache scenario.
+        */
+       if (parent && !in_fd) {
+               strcpy(dname, test_dir);
+               mount_dir = dirname(dname);
+               if (create)
+                       ret = mkdir(test_dir, 0700);
+               if (ret < 0 && errno != EEXIST) {
+                       strcat(dname, ": mkdir");
+                       perror(dname);
+                       return EXIT_FAILURE;
+               }
+       } else {
+               mount_dir = test_dir;
        }
 
-       test_dir = argv[1];
-       mount_fd = open(test_dir, O_RDONLY|O_DIRECTORY);
+       mount_fd = open(mount_dir, O_RDONLY|O_DIRECTORY);
        if (mount_fd < 0) {
-               perror("open test_dir");
+               perror(mount_dir);
                return EXIT_FAILURE;
        }
 
        /*
-        * create a large number of files to force allocation of new inode
-        * chunks on disk.
+        * Create the test files and remove leftover hardlinks from previous run
         */
-       for (i=0; i < NUMFILES; i++) {
+       for (i=0; create && i < numfiles; i++) {
                sprintf(fname, "%s/file%06d", test_dir, i);
+               sprintf(fname2, "%s/link%06d", test_dir, i);
                fd = open(fname, O_RDWR | O_CREAT | O_TRUNC, 0644);
                if (fd < 0) {
-                       printf("Warning (%s,%d), open(%s) failed.\n", __FILE__, __LINE__, fname);
+                       strcat(fname, ": open(O_CREAT)");
                        perror(fname);
                        return EXIT_FAILURE;
                }
                close(fd);
+               /* blow up leftovers hardlinks if they exist */
+               ret = unlink(fname2);
+               if (ret < 0 && errno != ENOENT) {
+                       strcat(fname2, ": unlink");
+                       perror(fname2);
+                       return EXIT_FAILURE;
+               }
        }
 
        /* sync to get the new inodes to hit the disk */
        sync();
 
-       /* create the handles */
-       for (i=0; i < NUMFILES; i++) {
+       /*
+        * encode the file handles or read them from file (-i) and maybe store
+        * them to a file (-o).
+        */
+       for (i=0; i < numfiles; i++) {
                sprintf(fname, "%s/file%06d", test_dir, i);
-               handle[i].fh.handle_bytes = MAX_HANDLE_SZ;
-               ret = name_to_handle_at(AT_FDCWD, fname, &handle[i].fh, &mount_id, 0);
+               if (in_fd) {
+                       ret = read(in_fd, (char *)&handle[i], sizeof(*handle));
+                       if (ret < sizeof(*handle)) {
+                               fprintf(stderr, "failed reading file handle #%d from '%s'\n", i, infile);
+                               return EXIT_FAILURE;
+                       }
+               } else {
+                       handle[i].fh.handle_bytes = MAX_HANDLE_SZ;
+                       ret = name_to_handle_at(AT_FDCWD, fname, &handle[i].fh, &mount_id, 0);
+                       if (ret < 0) {
+                               strcat(fname, ": name_to_handle");
+                               perror(fname);
+                               return EXIT_FAILURE;
+                       }
+               }
+               if (keepopen) {
+                       /* Open without close to keep unlinked files around */
+                       fd = open(fname, O_RDONLY);
+                       if (fd < 0) {
+                               strcat(fname, ": open(O_RDONLY)");
+                               perror(fname);
+                               return EXIT_FAILURE;
+                       }
+               }
+               if (out_fd) {
+                       ret = write(out_fd, (char *)&handle[i], sizeof(*handle));
+                       if (ret < sizeof(*handle)) {
+                               fprintf(stderr, "failed writing file handle #%d to '%s'\n", i, outfile);
+                               return EXIT_FAILURE;
+                       }
+               }
+       }
+
+       if (parent) {
+               if (in_fd) {
+                       ret = read(in_fd, (char *)&dir_handle, sizeof(*handle));
+                       if (ret < sizeof(*handle)) {
+                               fprintf(stderr, "failed reading dir file handle from '%s'\n", infile);
+                               return EXIT_FAILURE;
+                       }
+               } else {
+                       dir_handle.fh.handle_bytes = MAX_HANDLE_SZ;
+                       ret = name_to_handle_at(AT_FDCWD, test_dir, &dir_handle.fh, &mount_id, 0);
+                       if (ret < 0) {
+                               strcat(dname, ": name_to_handle");
+                               perror(dname);
+                               return EXIT_FAILURE;
+                       }
+               }
+               if (out_fd) {
+                       ret = write(out_fd, (char *)&dir_handle, sizeof(*handle));
+                       if (ret < sizeof(*handle)) {
+                               fprintf(stderr, "failed writing dir file handle to '%s'\n", outfile);
+                               return EXIT_FAILURE;
+                       }
+               }
+       }
+
+       /* write data to files */
+       for (i=0; wr && i < numfiles; i++) {
+               sprintf(fname, "%s/file%06d", test_dir, i);
+               fd = open(fname, O_WRONLY, 0644);
+               if (fd < 0) {
+                       strcat(fname, ": open");
+                       perror(fname);
+                       return EXIT_FAILURE;
+               }
+               if (write(fd, "aaaa", 4) != 4) {
+                       strcat(fname, ": write before");
+                       perror(fname);
+                       return EXIT_FAILURE;
+               }
+               close(fd);
+       }
+
+       /* If creating test set or saving files handles, we are done */
+       if (create || out_fd)
+               return EXIT_SUCCESS;
+
+       /* hardlink the files */
+       for (i=0; nlink > 1 && i < numfiles; i++) {
+               sprintf(fname, "%s/file%06d", test_dir, i);
+               sprintf(fname2, "%s/link%06d", test_dir, i);
+               ret = link(fname, fname2);
+               if (ret < 0) {
+                       strcat(fname2, ": link");
+                       perror(fname2);
+                       return EXIT_FAILURE;
+               }
+       }
+
+       /* rename the files */
+       for (i=0; move && i < numfiles; i++) {
+               sprintf(fname, "%s/file%06d", test_dir, i);
+               sprintf(fname2, "%s/link%06d", test_dir, i);
+               ret = rename(fname, fname2);
                if (ret < 0) {
-                       perror("name_to_handle");
+                       strcat(fname2, ": rename");
+                       perror(fname2);
                        return EXIT_FAILURE;
                }
        }
 
        /* unlink the files */
-       for (i=0; i < NUMFILES; i++) {
+       for (i=0; delete && i < numfiles; i++) {
                sprintf(fname, "%s/file%06d", test_dir, i);
+               sprintf(fname2, "%s/link%06d", test_dir, i);
                ret = unlink(fname);
                if (ret < 0) {
-                       perror("unlink");
+                       strcat(fname, ": unlink");
+                       perror(fname);
+                       return EXIT_FAILURE;
+               }
+               /* with -d flag, delete the hardlink if it exists */
+               if (!nlink)
+                       ret = unlink(fname2);
+               if (ret < 0 && errno != ENOENT) {
+                       strcat(fname2, ": unlink");
+                       perror(fname2);
+                       return EXIT_FAILURE;
+               }
+       }
+
+       if (parent && delete && !nlink) {
+               ret = rmdir(test_dir);
+               if (ret < 0) {
+                       strcat(dname, ": rmdir");
+                       perror(dname);
                        return EXIT_FAILURE;
                }
        }
@@ -114,30 +449,110 @@ int main(int argc, char **argv)
         * buftarg page cache is emptied so that the inode cluster has to be
         * fetched from disk again for the open_by_handle() call.
         */
-       ret = system("echo 3 > /proc/sys/vm/drop_caches");
-       if (ret < 0) {
-               perror("drop_caches");
-               return EXIT_FAILURE;
+       if (drop_caches) {
+               ret = system("echo 3 > /proc/sys/vm/drop_caches");
+               if (ret < 0) {
+                       perror("drop_caches");
+                       return EXIT_FAILURE;
+               }
        }
 
        /*
-        * now try to open the files by the stored handles. Expecting ENOENT
-        * for all of them.
+        * now try to open the files by the stored handles. Expecting ESTALE
+        * if all files and their hardlinks have been unlinked.
         */
-       for (i=0; i < NUMFILES; i++) {
+       for (i=0; i < numfiles; i++) {
                errno = 0;
-               fd = open_by_handle_at(mount_fd, &handle[i].fh, O_RDWR);
-               if (fd < 0 && (errno == ENOENT || errno == ESTALE)) {
+               fd = open_by_handle_at(mount_fd, &handle[i].fh, wrafter ? O_RDWR : O_RDONLY);
+               if ((nlink || keepopen) && fd >= 0) {
+                       if (rd) {
+                               char buf[4] = {0};
+                               int size = read(fd, buf, 4);
+                               if (size < 0) {
+                                       strcat(fname, ": read");
+                                       perror(fname);
+                                       return EXIT_FAILURE;
+                               }
+                               if (size < 4 || memcmp(buf, "aaaa", 4)) {
+                                       printf("open_by_handle(%s) returned stale data '%.*s'!\n", fname, size, buf);
+                               }
+                       }
+                       if (wrafter && write(fd, "aaaa", 4) != 4) {
+                               strcat(fname, ": write after");
+                               perror(fname);
+                               return EXIT_FAILURE;
+                       }
+                       if (!sleep_loop)
+                               close(fd);
+                       continue;
+               } else if (!nlink && !keepopen && fd < 0 && (errno == ENOENT || errno == ESTALE)) {
                        continue;
                }
+               sprintf(fname, "%s/file%06d", test_dir, i);
                if (fd >= 0) {
-                       printf("open_by_handle(%d) opened an unlinked file!\n", i);
+                       printf("open_by_handle(%s) opened an unlinked file!\n", fname);
                        close(fd);
-               } else
-                       printf("open_by_handle(%d) returned %d incorrectly on an unlinked file!\n", i, errno);
+               } else {
+                       printf("open_by_handle(%s) returned %d incorrectly on %s%s file!\n",
+                                       fname, errno,
+                                       nlink ? "a linked" : "an unlinked",
+                                       keepopen ? " open" : "");
+               }
                failed++;
        }
+
+       if (parent) {
+               fd = open_by_handle_at(mount_fd, &dir_handle.fh, O_RDONLY|O_DIRECTORY);
+               if (fd >= 0) {
+                       if (!nlink) {
+                               printf("open_by_handle(%s) opened an unlinked dir!\n", dname);
+                               return EXIT_FAILURE;
+                       } else if (rd) {
+                               /*
+                                * Sanity check dir fd - expect to access orig file IFF
+                                * it was not unlinked nor renamed.
+                                */
+                               strcpy(fname, "file000000");
+                               ret = faccessat(fd, fname, F_OK, 0);
+                               if ((ret == 0) != (!delete && !move) ||
+                                   ((ret < 0) && errno != ENOENT)) {
+                                       strcat(fname, ": unexpected result from faccessat");
+                                       perror(fname);
+                                       return EXIT_FAILURE;
+                               }
+                               /*
+                                * Expect to access link file if ran test with -l flag
+                                * (nlink > 1), -m flag (orig moved to link name) or
+                                * -u flag (which implied previous -l run).
+                                */
+                               strcpy(fname2, "link000000");
+                               ret = faccessat(fd, fname2, F_OK, 0);
+                               if (ret < 0 && (nlink > 1 || delete || move ||
+                                               errno != ENOENT)) {
+                                       strcat(fname2, ": unexpected result from faccessat");
+                                       perror(fname2);
+                                       return EXIT_FAILURE;
+                               }
+                       }
+                       if (!sleep_loop)
+                               close(fd);
+               } else if (nlink || !(errno == ENOENT || errno == ESTALE)) {
+                       printf("open_by_handle(%s) returned %d incorrectly on %s dir!\n",
+                                       dname, errno,
+                                       nlink ? "a linked" : "an unlinked");
+                       return EXIT_FAILURE;
+               }
+       }
+
        if (failed)
                return EXIT_FAILURE;
+
+       /*
+        * Sleep keeping files open by handle - the program need to be killed
+        * to release the open files.
+        */
+       while (sleep_loop)
+               sleep(1);
+
        return EXIT_SUCCESS;
 }