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| author | Rob Landley <rob@landley.net> | 2013-09-11 14:26:12 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-11 15:59:37 -0700 |
| commit | 16203a7a9422315bc929461503e3a046459ea5ff (patch) | |
| tree | f32de38261ac95e4ac3467595a3f7be445b02797 | |
| parent | 57f150a58c40cda598c31af8bceb8598f43c3e5f (diff) | |
| download | lwn-16203a7a9422315bc929461503e3a046459ea5ff.tar.gz lwn-16203a7a9422315bc929461503e3a046459ea5ff.zip | |
initmpfs: make rootfs use tmpfs when CONFIG_TMPFS enabled
Conditionally call the appropriate fs_init function and fill_super
functions. Add a use once guard to shmem_init() to simply succeed on a
second call.
(Note that IS_ENABLED() is a compile time constant so dead code
elimination removes unused function calls when CONFIG_TMPFS is disabled.)
Signed-off-by: Rob Landley <rob@landley.net>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | init/do_mounts.c | 10 | ||||
| -rw-r--r-- | mm/shmem.c | 4 |
2 files changed, 12 insertions, 2 deletions
diff --git a/init/do_mounts.c b/init/do_mounts.c index 5d8d48fd0ee4..e27908b949d4 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -27,6 +27,7 @@ #include <linux/fs_struct.h> #include <linux/slab.h> #include <linux/ramfs.h> +#include <linux/shmem_fs.h> #include <linux/nfs_fs.h> #include <linux/nfs_fs_sb.h> @@ -598,7 +599,8 @@ static struct dentry *rootfs_mount(struct file_system_type *fs_type, if (test_and_set_bit(0, &once)) return ERR_PTR(-ENODEV); - return mount_nodev(fs_type, flags, data, ramfs_fill_super); + return mount_nodev(fs_type, flags, data, + IS_ENABLED(CONFIG_TMPFS) ? shmem_fill_super : ramfs_fill_super); } static struct file_system_type rootfs_fs_type = { @@ -614,7 +616,11 @@ int __init init_rootfs(void) if (err) return err; - err = init_ramfs_fs(); + if (IS_ENABLED(CONFIG_TMPFS)) + err = shmem_init(); + else + err = init_ramfs_fs(); + if (err) unregister_filesystem(&rootfs_fs_type); diff --git a/mm/shmem.c b/mm/shmem.c index a1b8bf4391c2..8297623fcaed 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2819,6 +2819,10 @@ int __init shmem_init(void) { int error; + /* If rootfs called this, don't re-init */ + if (shmem_inode_cachep) + return 0; + error = bdi_init(&shmem_backing_dev_info); if (error) goto out4; |