#define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include "cgroup_helpers.h" /* * To avoid relying on the system setup, when setup_cgroup_env is called * we create a new mount namespace, and cgroup namespace. The cgroup2 * root is mounted at CGROUP_MOUNT_PATH * * Unfortunately, most people don't have cgroupv2 enabled at this point in time. * It's easier to create our own mount namespace and manage it ourselves. * * We assume /mnt exists. */ #define WALK_FD_LIMIT 16 #define CGROUP_MOUNT_PATH "/mnt" #define CGROUP_WORK_DIR "/cgroup-test-work-dir" #define format_cgroup_path(buf, path) \ snprintf(buf, sizeof(buf), "%s%s%s", CGROUP_MOUNT_PATH, \ CGROUP_WORK_DIR, path) /** * setup_cgroup_environment() - Setup the cgroup environment * * After calling this function, cleanup_cgroup_environment should be called * once testing is complete. * * This function will print an error to stderr and return 1 if it is unable * to setup the cgroup environment. If setup is successful, 0 is returned. */ int setup_cgroup_environment(void) { char cgroup_workdir[PATH_MAX + 1]; format_cgroup_path(cgroup_workdir, ""); if (unshare(CLONE_NEWNS)) { log_err("unshare"); return 1; } if (mount("none", "/", NULL, MS_REC | MS_PRIVATE, NULL)) { log_err("mount fakeroot"); return 1; } if (mount("none", CGROUP_MOUNT_PATH, "cgroup2", 0, NULL)) { log_err("mount cgroup2"); return 1; } /* Cleanup existing failed runs, now that the environment is setup */ cleanup_cgroup_environment(); if (mkdir(cgroup_workdir, 0777) && errno != EEXIST) { log_err("mkdir cgroup work dir"); return 1; } return 0; } static int nftwfunc(const char *filename, const struct stat *statptr, int fileflags, struct FTW *pfwt) { if ((fileflags & FTW_D) && rmdir(filename)) log_err("Removing cgroup: %s", filename); return 0; } static int join_cgroup_from_top(char *cgroup_path) { char cgroup_procs_path[PATH_MAX + 1]; pid_t pid = getpid(); int fd, rc = 0; snprintf(cgroup_procs_path, sizeof(cgroup_procs_path), "%s/cgroup.procs", cgroup_path); fd = open(cgroup_procs_path, O_WRONLY); if (fd < 0) { log_err("Opening Cgroup Procs: %s", cgroup_procs_path); return 1; } if (dprintf(fd, "%d\n", pid) < 0) { log_err("Joining Cgroup"); rc = 1; } close(fd); return rc; } /** * join_cgroup() - Join a cgroup * @path: The cgroup path, relative to the workdir, to join * * This function expects a cgroup to already be created, relative to the cgroup * work dir, and it joins it. For example, passing "/my-cgroup" as the path * would actually put the calling process into the cgroup * "/cgroup-test-work-dir/my-cgroup" * * On success, it returns 0, otherwise on failure it returns 1. */ int join_cgroup(char *path) { char cgroup_path[PATH_MAX + 1]; format_cgroup_path(cgroup_path, path); return join_cgroup_from_top(cgroup_path); } /** * cleanup_cgroup_environment() - Cleanup Cgroup Testing Environment * * This is an idempotent function to delete all temporary cgroups that * have been created during the test, including the cgroup testing work * directory. * * At call time, it moves the calling process to the root cgroup, and then * runs the deletion process. It is idempotent, and should not fail, unless * a process is lingering. * * On failure, it will print an error to stderr, and try to continue. */ void cleanup_cgroup_environment(void) { char cgroup_workdir[PATH_MAX + 1]; format_cgroup_path(cgroup_workdir, ""); join_cgroup_from_top(CGROUP_MOUNT_PATH); nftw(cgroup_workdir, nftwfunc, WALK_FD_LIMIT, FTW_DEPTH | FTW_MOUNT); } /** * create_and_get_cgroup() - Create a cgroup, relative to workdir, and get the FD * @path: The cgroup path, relative to the workdir, to join * * This function creates a cgroup under the top level workdir and returns the * file descriptor. It is idempotent. * * On success, it returns the file descriptor. On failure it returns 0. * If there is a failure, it prints the error to stderr. */ int create_and_get_cgroup(char *path) { char cgroup_path[PATH_MAX + 1]; int fd; format_cgroup_path(cgroup_path, path); if (mkdir(cgroup_path, 0777) && errno != EEXIST) { log_err("mkdiring cgroup"); return 0; } fd = open(cgroup_path, O_RDONLY); if (fd < 0) { log_err("Opening Cgroup"); return 0; } return fd; } m>
authorJan Kara <jack@suse.cz>2016-08-10 17:22:44 +0200
committerDan Williams <dan.j.williams@intel.com>2016-12-26 20:29:24 -0800
commitc6dcf52c23d2d3fb5235cec42d7dd3f786b87d55 (patch)
tree7e63a6c0225a769e679b194f54b5723e4cfba385 /include/pcmcia/device_id.h
parente568df6b84ff05a22467503afc11bee7a6ba0700 (diff)
mm: Invalidate DAX radix tree entries only if appropriate
Currently invalidate_inode_pages2_range() and invalidate_mapping_pages() just delete all exceptional radix tree entries they find. For DAX this is not desirable as we track cache dirtiness in these entries and when they are evicted, we may not flush caches although it is necessary. This can for example manifest when we write to the same block both via mmap and via write(2) (to different offsets) and fsync(2) then does not properly flush CPU caches when modification via write(2) was the last one. Create appropriate DAX functions to handle invalidation of DAX entries for invalidate_inode_pages2_range() and invalidate_mapping_pages() and wire them up into the corresponding mm functions. Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'include/pcmcia/device_id.h')