| /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
| |
| /*** |
| This file is part of systemd. |
| |
| Copyright 2010 Lennart Poettering |
| |
| systemd is free software; you can redistribute it and/or modify it |
| under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| systemd is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| ***/ |
| |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/sysinfo.h> |
| #include <sys/inotify.h> |
| #include <fcntl.h> |
| #include <sys/mman.h> |
| #include <unistd.h> |
| #include <libudev.h> |
| |
| #include "log.h" |
| #include "readahead-common.h" |
| #include "util.h" |
| |
| int file_verify(int fd, const char *fn, off_t file_size_max, struct stat *st) { |
| assert(fd >= 0); |
| assert(fn); |
| assert(st); |
| |
| if (fstat(fd, st) < 0) { |
| log_warning("fstat(%s) failed: %m", fn); |
| return -errno; |
| } |
| |
| if (!S_ISREG(st->st_mode)) { |
| log_debug("Not preloading special file %s", fn); |
| return 0; |
| } |
| |
| if (st->st_size <= 0 || st->st_size > file_size_max) { |
| log_debug("Not preloading file %s with size out of bounds %llu", fn, (unsigned long long) st->st_size); |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| int fs_on_ssd(const char *p) { |
| struct stat st; |
| struct udev *udev = NULL; |
| struct udev_device *udev_device = NULL, *look_at = NULL; |
| bool b = false; |
| const char *devtype, *rotational, *model, *id; |
| |
| assert(p); |
| |
| if (stat(p, &st) < 0) |
| return -errno; |
| |
| if (major(st.st_dev) == 0) |
| return false; |
| |
| if (!(udev = udev_new())) |
| return -ENOMEM; |
| |
| if (!(udev_device = udev_device_new_from_devnum(udev, 'b', st.st_dev))) |
| goto finish; |
| |
| if ((devtype = udev_device_get_property_value(udev_device, "DEVTYPE")) && |
| streq(devtype, "partition")) |
| look_at = udev_device_get_parent(udev_device); |
| else |
| look_at = udev_device; |
| |
| if (!look_at) |
| goto finish; |
| |
| /* First, try high-level property */ |
| if ((id = udev_device_get_property_value(look_at, "ID_SSD"))) { |
| b = streq(id, "1"); |
| goto finish; |
| } |
| |
| /* Second, try kernel attribute */ |
| if ((rotational = udev_device_get_sysattr_value(look_at, "queue/rotational"))) |
| if ((b = streq(rotational, "0"))) |
| goto finish; |
| |
| /* Finally, fallback to heuristics */ |
| if (!(look_at = udev_device_get_parent(look_at))) |
| goto finish; |
| |
| if ((model = udev_device_get_sysattr_value(look_at, "model"))) |
| b = !!strstr(model, "SSD"); |
| |
| finish: |
| if (udev_device) |
| udev_device_unref(udev_device); |
| |
| if (udev) |
| udev_unref(udev); |
| |
| return b; |
| } |
| |
| int fs_on_read_only(const char *p) { |
| struct stat st; |
| struct udev *udev = NULL; |
| struct udev_device *udev_device = NULL; |
| bool b = false; |
| const char *read_only; |
| |
| assert(p); |
| |
| if (stat(p, &st) < 0) |
| return -errno; |
| |
| if (major(st.st_dev) == 0) |
| return false; |
| |
| if (!(udev = udev_new())) |
| return -ENOMEM; |
| |
| if (!(udev_device = udev_device_new_from_devnum(udev, 'b', st.st_dev))) |
| goto finish; |
| |
| if ((read_only = udev_device_get_sysattr_value(udev_device, "ro"))) |
| if ((b = streq(read_only, "1"))) |
| goto finish; |
| |
| finish: |
| if (udev_device) |
| udev_device_unref(udev_device); |
| |
| if (udev) |
| udev_unref(udev); |
| |
| return b; |
| } |
| |
| bool enough_ram(void) { |
| struct sysinfo si; |
| |
| assert_se(sysinfo(&si) >= 0); |
| |
| return si.totalram > 127 * 1024*1024; /* Enable readahead only |
| * with at least 128MB |
| * memory */ |
| } |
| |
| int open_inotify(void) { |
| int fd; |
| |
| if ((fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) { |
| log_error("Failed to create inotify handle: %m"); |
| return -errno; |
| } |
| |
| mkdir("/dev/.systemd", 0755); |
| mkdir("/dev/.systemd/readahead", 0755); |
| |
| if (inotify_add_watch(fd, "/dev/.systemd/readahead", IN_CREATE) < 0) { |
| log_error("Failed to watch /dev/.systemd/readahead: %m"); |
| close_nointr_nofail(fd); |
| return -errno; |
| } |
| |
| return fd; |
| } |
| |
| ReadaheadShared *shared_get(void) { |
| int fd; |
| ReadaheadShared *m = NULL; |
| |
| mkdir("/dev/.systemd", 0755); |
| mkdir("/dev/.systemd/readahead", 0755); |
| |
| if ((fd = open("/dev/.systemd/readahead/shared", O_CREAT|O_RDWR|O_CLOEXEC, 0644)) < 0) { |
| log_error("Failed to create shared memory segment: %m"); |
| goto finish; |
| } |
| |
| if (ftruncate(fd, sizeof(ReadaheadShared)) < 0) { |
| log_error("Failed to truncate shared memory segment: %m"); |
| goto finish; |
| } |
| |
| if ((m = mmap(NULL, sizeof(ReadaheadShared), PROT_WRITE|PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) { |
| log_error("Failed to mmap shared memory segment: %m"); |
| m = NULL; |
| goto finish; |
| } |
| |
| finish: |
| if (fd >= 0) |
| close_nointr_nofail(fd); |
| |
| return m; |
| } |
| |
| |
| #define BUMP_REQUEST_NR (16*1024) |
| |
| int bump_request_nr(const char *p) { |
| struct stat st; |
| struct udev *udev = NULL; |
| struct udev_device *udev_device = NULL, *look_at = NULL; |
| const char *nr_requests; |
| uint64_t u; |
| char nr[64], *ap = NULL; |
| int r; |
| |
| assert(p); |
| |
| if (stat(p, &st) < 0) |
| return -errno; |
| |
| if (major(st.st_dev) == 0) |
| return 0; |
| |
| if (!(udev = udev_new())) |
| return -ENOMEM; |
| |
| if (!(udev_device = udev_device_new_from_devnum(udev, 'b', st.st_dev))) { |
| r = -ENOENT; |
| goto finish; |
| } |
| |
| look_at = udev_device; |
| if (!(nr_requests = udev_device_get_sysattr_value(look_at, "queue/nr_requests"))) { |
| |
| /* Hmm, if the block device doesn't have a queue |
| * subdir, the let's look in the parent */ |
| look_at = udev_device_get_parent(udev_device); |
| nr_requests = udev_device_get_sysattr_value(look_at, "queue/nr_requests"); |
| } |
| |
| if (!nr_requests) { |
| r = -ENOENT; |
| goto finish; |
| } |
| |
| if (safe_atou64(nr_requests, &u) >= 0 && u >= BUMP_REQUEST_NR) { |
| r = 0; |
| goto finish; |
| } |
| |
| if (asprintf(&ap, "%s/queue/nr_requests", udev_device_get_syspath(look_at)) < 0) { |
| r = -ENOMEM; |
| goto finish; |
| } |
| |
| snprintf(nr, sizeof(nr), "%lu", (unsigned long) BUMP_REQUEST_NR); |
| |
| if ((r = write_one_line_file(ap, nr)) < 0) |
| goto finish; |
| |
| log_info("Bumped block_nr parameter of %s to %lu. This is a temporary hack and should be removed one day.", udev_device_get_devnode(look_at), (unsigned long) BUMP_REQUEST_NR); |
| r = 1; |
| |
| finish: |
| if (udev_device) |
| udev_device_unref(udev_device); |
| |
| if (udev) |
| udev_unref(udev); |
| |
| free(ap); |
| |
| return r; |
| } |