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5cf37738e0
Paulo Alcantara says:
====================
Experimental SMB rootfs support
This patch series enables Linux to mount root file systems over the
network by utilizing SMB protocol.
Upstream commit 8eecd1c2e5 ("cifs: Add support for root file
systems") introduced a new CONFIG_CIFS_ROOT option, a virtual device
(Root_CIFS) and a kernel cmdline parameter "cifsroot=" which tells the
kernel to actually mount the root filesystem over a SMB share.
The feature relies on ipconfig to set up the network prior to mounting
the rootfs, so when it is set along with "cifsroot=" parameter:
(1) cifs_root_setup() parses all necessary data out of "cifsroot="
parameter for the init process know how to mount the SMB rootfs
(e.g. SMB server address, mount options).
(2) If DHCP failed for some reason in ipconfig, we keep retrying
forever as we have nowhere to go for NFS or SMB root
filesystems (see PATCH 2/2). Otherwise go to (3).
(3) mount_cifs_root() is then called by mount_root() (ROOT_DEV ==
Root_CIFS), retrieves early parsed data from (1), then attempt to
mount SMB rootfs by CIFSROOT_RETRY_MAX times at most (see PATCH
1/2).
(4) If all attempts failed, fall back to floppy drive, otherwise
continue the boot process with rootfs mounted over a SMB share.
My idea was to keep the same behavior of nfsroot - as it seems to work
for most users so far.
For more information on how this feature works, see
Documentation/filesystems/cifs/cifsroot.txt.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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.