This patch adds support to mounting devices using a kernel parameter. Such feature is usefull for virtual guests. It allows easily automating mounts without having to change the base image (which can be read-only).
In /tools/kvm we are interested in such feature to allow us to automatically mount user home directory using virtio-9p from the host to the guest filesystem under '/hostfs'. Cc: Avi Kivity <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Pekka Enberg <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- Documentation/kernel-parameters.txt | 6 +++ init/do_mounts.c | 61 +++++++++++++++++++++++++++++++++++ 2 files changed, 67 insertions(+), 0 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index aa47be7..e1955fb 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1476,6 +1476,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. log everything. Information is printed at KERN_DEBUG so loglevel=8 may also need to be specified. + mount= + [KNL] Mount a device to a mount point after loading + rootfs and setting up devices. Can be used to mount + up to 16 devices. + Format: <source>,<destination>,<fs>[,<params>] + mousedev.tap_time= [MOUSE] Maximum time between finger touching and leaving touchpad surface for touch to be considered diff --git a/init/do_mounts.c b/init/do_mounts.c index c0851a8..0948f1d 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -29,9 +29,24 @@ int root_mountflags = MS_RDONLY | MS_SILENT; static char * __initdata root_device_name; static char __initdata saved_root_name[64]; static int __initdata root_wait; +static char * __initdata user_mount[16]; +static int __initdata user_mount_count; dev_t ROOT_DEV; +static int __init setup_user_mount(char *str) +{ + if (user_mount_count > 15) { + printk(KERN_ERR "More than 16 'mount=' options specified.") + return 1; + } + + user_mount[user_mount_count++] = str; + + return 1; +} +__setup("mount=", setup_user_mount); + static int __init load_ramdisk(char *str) { rd_doload = simple_strtol(str,NULL,0) & 3; @@ -431,6 +446,51 @@ void __init mount_root(void) #endif } +int __init do_user_mounts(void) +{ + int i, res; + char *src, *dst, *fs, *params, *cur; + + for (i = 0; i < user_mount_count; i++) { + src = user_mount[i]; + cur = strstr(user_mount[i], ","); + if (!cur) + goto fail_str; + + *cur = '\0'; + dst = ++cur; + + cur = strstr(cur, ","); + if (!cur) + goto fail_str; + + *cur = '\0'; + fs = ++cur; + + cur = strstr(cur, ","); + if (cur) { + *cur = '\0'; + params = ++cur; + } else { + params = NULL; + } + + res = sys_mount(src, dst, fs, 0, params); + if (res == 0) + printk(KERN_INFO "Mounted (%s filesystem) %s to %s\n", + fs, src, dst); + else + printk(KERN_ERR "Failed mounting (%s filesystem) %s to" + " %s. Err: %d\n", fs, src, dst, res); + } + + return 0; + +fail_str: + printk(KERN_ERR "Bad mount str: %s\n", user_mount[i]); + return -1; +} + /* * Prepare the namespace - decide what/where to mount, load ramdisks, etc. */ @@ -490,4 +550,5 @@ out: devtmpfs_mount("dev"); sys_mount(".", "/", NULL, MS_MOVE, NULL); sys_chroot((const char __user __force *)"."); + do_user_mounts(); } -- 1.7.6 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
