From c2637e80a09e0d6c698d2771d7230f59c2138122 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 14 Nov 2020 19:19:57 +0100 Subject: init: refactor name_to_dev_t Split each case into a self-contained helper, and move the block dependent code entirely under the pre-existing #ifdef CONFIG_BLOCK. This allows to remove the blk_lookup_devt stub in genhd.h. Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman Reviewed-by: Jan Kara Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Acked-by: Tejun Heo Signed-off-by: Jens Axboe --- init/do_mounts.c | 183 +++++++++++++++++++++++++++---------------------------- 1 file changed, 90 insertions(+), 93 deletions(-) (limited to 'init/do_mounts.c') diff --git a/init/do_mounts.c b/init/do_mounts.c index b5f9604d0c98..aef2f24461c7 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -90,7 +90,6 @@ no_match: return 0; } - /** * devt_from_partuuid - looks up the dev_t of a partition by its UUID * @uuid_str: char array containing ascii UUID @@ -186,7 +185,83 @@ static int match_dev_by_label(struct device *dev, const void *data) return 0; } -#endif + +static dev_t devt_from_partlabel(const char *label) +{ + struct device *dev; + dev_t devt = 0; + + dev = class_find_device(&block_class, NULL, label, &match_dev_by_label); + if (dev) { + devt = dev->devt; + put_device(dev); + } + + return devt; +} + +static dev_t devt_from_devname(const char *name) +{ + dev_t devt = 0; + int part; + char s[32]; + char *p; + + if (strlen(name) > 31) + return 0; + strcpy(s, name); + for (p = s; *p; p++) { + if (*p == '/') + *p = '!'; + } + + devt = blk_lookup_devt(s, 0); + if (devt) + return devt; + + /* + * Try non-existent, but valid partition, which may only exist after + * opening the device, like partitioned md devices. + */ + while (p > s && isdigit(p[-1])) + p--; + if (p == s || !*p || *p == '0') + return 0; + + /* try disk name without */ + part = simple_strtoul(p, NULL, 10); + *p = '\0'; + devt = blk_lookup_devt(s, part); + if (devt) + return devt; + + /* try disk name without p */ + if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p') + return 0; + p[-1] = '\0'; + return blk_lookup_devt(s, part); +} +#endif /* CONFIG_BLOCK */ + +static dev_t devt_from_devnum(const char *name) +{ + unsigned maj, min, offset; + dev_t devt = 0; + char *p, dummy; + + if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 || + sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, &dummy) == 3) { + devt = MKDEV(maj, min); + if (maj != MAJOR(devt) || min != MINOR(devt)) + return 0; + } else { + devt = new_decode_dev(simple_strtoul(name, &p, 16)); + if (*p) + return 0; + } + + return devt; +} /* * Convert a name into device number. We accept the following variants: @@ -218,101 +293,23 @@ static int match_dev_by_label(struct device *dev, const void *data) * name contains slashes, the device name has them replaced with * bangs. */ - dev_t name_to_dev_t(const char *name) { - char s[32]; - char *p; - dev_t res = 0; - int part; - + if (strcmp(name, "/dev/nfs") == 0) + return Root_NFS; + if (strcmp(name, "/dev/cifs") == 0) + return Root_CIFS; + if (strcmp(name, "/dev/ram") == 0) + return Root_RAM0; #ifdef CONFIG_BLOCK - if (strncmp(name, "PARTUUID=", 9) == 0) { - name += 9; - res = devt_from_partuuid(name); - if (!res) - goto fail; - goto done; - } else if (strncmp(name, "PARTLABEL=", 10) == 0) { - struct device *dev; - - dev = class_find_device(&block_class, NULL, name + 10, - &match_dev_by_label); - if (!dev) - goto fail; - - res = dev->devt; - put_device(dev); - goto done; - } + if (strncmp(name, "PARTUUID=", 9) == 0) + return devt_from_partuuid(name + 9); + if (strncmp(name, "PARTLABEL=", 10) == 0) + return devt_from_partlabel(name + 10); + if (strncmp(name, "/dev/", 5) == 0) + return devt_from_devname(name + 5); #endif - - if (strncmp(name, "/dev/", 5) != 0) { - unsigned maj, min, offset; - char dummy; - - if ((sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2) || - (sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, &dummy) == 3)) { - res = MKDEV(maj, min); - if (maj != MAJOR(res) || min != MINOR(res)) - goto fail; - } else { - res = new_decode_dev(simple_strtoul(name, &p, 16)); - if (*p) - goto fail; - } - goto done; - } - - name += 5; - res = Root_NFS; - if (strcmp(name, "nfs") == 0) - goto done; - res = Root_CIFS; - if (strcmp(name, "cifs") == 0) - goto done; - res = Root_RAM0; - if (strcmp(name, "ram") == 0) - goto done; - - if (strlen(name) > 31) - goto fail; - strcpy(s, name); - for (p = s; *p; p++) - if (*p == '/') - *p = '!'; - res = blk_lookup_devt(s, 0); - if (res) - goto done; - - /* - * try non-existent, but valid partition, which may only exist - * after revalidating the disk, like partitioned md devices - */ - while (p > s && isdigit(p[-1])) - p--; - if (p == s || !*p || *p == '0') - goto fail; - - /* try disk name without */ - part = simple_strtoul(p, NULL, 10); - *p = '\0'; - res = blk_lookup_devt(s, part); - if (res) - goto done; - - /* try disk name without p */ - if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p') - goto fail; - p[-1] = '\0'; - res = blk_lookup_devt(s, part); - if (res) - goto done; - -fail: - return 0; -done: - return res; + return devt_from_devnum(name); } EXPORT_SYMBOL_GPL(name_to_dev_t); -- cgit v1.2.3