mainlining shenanigans
Let fat handle idmapped mounts. This allows to have the same fat mount appear in multiple locations with different id mappings. This allows to expose a vfat formatted USB stick to multiple user with different ids on the host or in user namespaces allowing for dac permissions: mount -o uid=1000,gid=1000 /dev/sdb /mnt u1001@f2-vm:/lower1$ ls -ln /mnt/ total 4 -rwxr-xr-x 1 1000 1000 4 Oct 28 03:44 aaa -rwxr-xr-x 1 1000 1000 0 Oct 28 01:09 bbb -rwxr-xr-x 1 1000 1000 0 Oct 28 01:10 ccc -rwxr-xr-x 1 1000 1000 0 Oct 28 03:46 ddd -rwxr-xr-x 1 1000 1000 0 Oct 28 04:01 eee mount-idmapped --map-mount b:1000:1001:1 u1001@f2-vm:/lower1$ ls -ln /lower1/ total 4 -rwxr-xr-x 1 1001 1001 4 Oct 28 03:44 aaa -rwxr-xr-x 1 1001 1001 0 Oct 28 01:09 bbb -rwxr-xr-x 1 1001 1001 0 Oct 28 01:10 ccc -rwxr-xr-x 1 1001 1001 0 Oct 28 03:46 ddd -rwxr-xr-x 1 1001 1001 0 Oct 28 04:01 eee u1001@f2-vm:/lower1$ touch /lower1/fff u1001@f2-vm:/lower1$ ls -ln /lower1/fff -rwxr-xr-x 1 1001 1001 0 Oct 28 04:03 /lower1/fff u1001@f2-vm:/lower1$ ls -ln /mnt/fff -rwxr-xr-x 1 1000 1000 0 Oct 28 04:03 /mnt/fff Link: https://lore.kernel.org/r/20210121131959.646623-38-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> |
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arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.