[PATCH 12/24] init: move the nfs/cifs/ram special cases out of name_to_dev_t

Christoph Hellwig
2023-05-31T12:58:04Z

The nfs/cifs/ram special case only needs to be parsed once, and only in
the boot code. Move them out of name_to_dev_t and into
prepare_namespace.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
Documentation/admin-guide/kernel-parameters.txt | 7 ++++++-
init/do_mounts.c | 14 ++++++--------
2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 9e5bab29685ff0..457c342d15977e 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5452,7 +5452,12 @@
port and the regular usb controller gets disabled.

root= [KNL] Root filesystem
- See name_to_dev_t comment in init/do_mounts.c.
+ Usually this a a block device specifier of some kind,
+ see the name_to_dev_t comment in init/do_mounts.c for
+ details.
+ Alternatively this can be "ram" for the legacy initial
+ ramdisk, "nfs" and "cifs" for root on a network file
+ system, or "mtd" and "ubi" for mounting from raw flash.

rootdelay= [KNL] Delay (in seconds) to pause before attempting to
mount the root filesystem
diff --git a/init/do_mounts.c b/init/do_mounts.c
index d5c06c1546e82c..86599faf2bf8a1 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -248,7 +248,6 @@ static dev_t devt_from_devnum(const char *name)
*
* 1) <hex_major><hex_minor> device number in hexadecimal represents itself
* no leading 0x, for example b302.
- * 2) /dev/nfs represents Root_NFS (0xff)
* 3) /dev/<disk_name> represents the device number of disk
* 4) /dev/<disk_name><decimal> represents the device number
* of partition - device number of disk plus the partition number
@@ -266,7 +265,6 @@ static dev_t devt_from_devnum(const char *name)
* a colon.
* 9) PARTLABEL=<name> with name being the GPT partition label.
* MSDOS partitions do not support labels!
- * 10) /dev/cifs represents Root_CIFS (0xfe)
*
* If name doesn't have fall into the categories above, we return (0,0).
* block_class is used to check if something is a disk name. If the disk
@@ -275,12 +273,6 @@ static dev_t devt_from_devnum(const char *name)
*/
dev_t name_to_dev_t(const char *name)
{
- 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)
return devt_from_partuuid(name + 9);
@@ -631,6 +623,12 @@ static dev_t __init parse_root_device(char *root_device_name)
if (!strncmp(root_device_name, "mtd", 3) ||
!strncmp(root_device_name, "ubi", 3))
return Root_Generic;
+ if (strcmp(root_device_name, "/dev/nfs") == 0)
+ return Root_NFS;
+ if (strcmp(root_device_name, "/dev/cifs") == 0)
+ return Root_CIFS;
+ if (strcmp(root_device_name, "/dev/ram") == 0)
+ return Root_RAM0;
return name_to_dev_t(root_device_name);
}

--
2.39.2