X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Freadahead%2Freadahead-common.c;h=1599ac15a476b628bc27b86a0176a446bf84bd86;hp=67214ec3790639e1da651120fa94c05f230f7439;hb=2826d14091e43ed3397d862dee79d09d0115c84e;hpb=e5e83e8362e946890ac991fc86a2c5869f9befdf diff --git a/src/readahead/readahead-common.c b/src/readahead/readahead-common.c index 67214ec37..1599ac15a 100644 --- a/src/readahead/readahead-common.c +++ b/src/readahead/readahead-common.c @@ -6,16 +6,16 @@ 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 + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 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. + Lesser General Public License for more details. - You should have received a copy of the GNU General Public License + You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see . ***/ @@ -32,6 +32,7 @@ #include "log.h" #include "readahead-common.h" #include "util.h" +#include "missing.h" int file_verify(int fd, const char *fn, off_t file_size_max, struct stat *st) { assert(fd >= 0); @@ -62,23 +63,74 @@ int fs_on_ssd(const char *p) { struct udev_device *udev_device = NULL, *look_at = NULL; bool b = false; const char *devtype, *rotational, *model, *id; + int r; assert(p); if (stat(p, &st) < 0) return -errno; - if (major(st.st_dev) == 0) + if (major(st.st_dev) == 0) { + _cleanup_fclose_ FILE *f = NULL; + int mount_id; + struct file_handle *h; + + /* Might be btrfs, which exposes "ssd" as mount flag if it is on ssd. + * + * We first determine the mount ID here, if we can, + * and then lookup the mount ID in mountinfo to find + * the mount options. */ + + h = alloca(MAX_HANDLE_SZ); + h->handle_bytes = MAX_HANDLE_SZ; + r = name_to_handle_at(AT_FDCWD, p, h, &mount_id, AT_SYMLINK_FOLLOW); + if (r < 0) + return false; + + f = fopen("/proc/self/mountinfo", "re"); + if (!f) + return false; + + for (;;) { + char line[LINE_MAX], *e; + _cleanup_free_ char *opts = NULL; + int mid; + + if (!fgets(line, sizeof(line), f)) + return false; + + truncate_nl(line); + + if (sscanf(line, "%i", &mid) != 1) + continue; + + if (mid != mount_id) + continue; + + e = strstr(line, " - "); + if (!e) + continue; + + if (sscanf(e+3, "%*s %*s %ms", &opts) != 1) + continue; + + if (streq(opts, "ssd") || startswith(opts, "ssd,") || endswith(opts, ",ssd") || strstr(opts, ",ssd,")) + return true; + } + return false; + } - if (!(udev = udev_new())) + udev = udev_new(); + if (!udev) return -ENOMEM; - if (!(udev_device = udev_device_new_from_devnum(udev, 'b', st.st_dev))) + udev_device = udev_device_new_from_devnum(udev, 'b', st.st_dev); + if (!udev_device) goto finish; - if ((devtype = udev_device_get_property_value(udev_device, "DEVTYPE")) && - streq(devtype, "partition")) + devtype = udev_device_get_property_value(udev_device, "DEVTYPE"); + if (devtype && streq(devtype, "partition")) look_at = udev_device_get_parent(udev_device); else look_at = udev_device; @@ -87,21 +139,26 @@ int fs_on_ssd(const char *p) { goto finish; /* First, try high-level property */ - if ((id = udev_device_get_property_value(look_at, "ID_SSD"))) { + id = udev_device_get_property_value(look_at, "ID_SSD"); + if (id) { 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; + rotational = udev_device_get_sysattr_value(look_at, "queue/rotational"); + if (rotational) { + b = streq(rotational, "0"); + goto finish; + } /* Finally, fallback to heuristics */ - if (!(look_at = udev_device_get_parent(look_at))) + look_at = udev_device_get_parent(look_at); + if (!look_at) goto finish; - if ((model = udev_device_get_sysattr_value(look_at, "model"))) + model = udev_device_get_sysattr_value(look_at, "model"); + if (model) b = !!strstr(model, "SSD"); finish: @@ -170,7 +227,7 @@ int open_inotify(void) { mkdir("/run/systemd/readahead", 0755); if (inotify_add_watch(fd, "/run/systemd/readahead", IN_CREATE) < 0) { - log_error("Failed to watch /run/systemd/readahead: %m"); + log_error("Failed to add watch on /run/systemd/readahead: %m"); close_nointr_nofail(fd); return -errno; } @@ -208,9 +265,13 @@ finish: return m; } -#define BUMP_REQUEST_NR (16*1024) +/* We use 20K instead of the more human digestable 16K here. Why? + Simply so that it is more unlikely that users end up picking this + value too so that we can recognize better whether the user changed + the value while we had it temporarily bumped. */ +#define BUMP_REQUEST_NR (20*1024) -int bump_request_nr(const char *p) { +int block_bump_request_nr(const char *p) { struct stat st; uint64_t u; char *ap = NULL, *line = NULL; @@ -267,3 +328,83 @@ finish: return r; } + +int block_get_readahead(const char *p, uint64_t *bytes) { + struct stat st; + char *ap = NULL, *line = NULL; + int r; + dev_t d; + uint64_t u; + + assert(p); + assert(bytes); + + if (stat(p, &st) < 0) + return -errno; + + if (major(st.st_dev) == 0) + return 0; + + d = st.st_dev; + block_get_whole_disk(d, &d); + + if (asprintf(&ap, "/sys/dev/block/%u:%u/bdi/read_ahead_kb", major(d), minor(d)) < 0) { + r = -ENOMEM; + goto finish; + } + + r = read_one_line_file(ap, &line); + if (r < 0) + goto finish; + + r = safe_atou64(line, &u); + if (r < 0) + goto finish; + + *bytes = u * 1024ULL; + +finish: + free(ap); + free(line); + + return r; +} + +int block_set_readahead(const char *p, uint64_t bytes) { + struct stat st; + char *ap = NULL, *line = NULL; + int r; + dev_t d; + + assert(p); + assert(bytes); + + if (stat(p, &st) < 0) + return -errno; + + if (major(st.st_dev) == 0) + return 0; + + d = st.st_dev; + block_get_whole_disk(d, &d); + + if (asprintf(&ap, "/sys/dev/block/%u:%u/bdi/read_ahead_kb", major(d), minor(d)) < 0) { + r = -ENOMEM; + goto finish; + } + + if (asprintf(&line, "%llu", (unsigned long long) bytes / 1024ULL) < 0) { + r = -ENOMEM; + goto finish; + } + + r = write_one_line_file(ap, line); + if (r < 0) + goto finish; + +finish: + free(ap); + free(line); + + return r; +}