BMC/Intel-BMC/linux.git/fs/nfs/nfsroot.c, branch dev

NFS: a couple off by ones

2015-01-31T01:43:30+00:00

These tests are off by one because if len == sizeof(nfs_export_path) then we have truncated the name. Signed-off-by: Dan Carpenter Signed-off-by: Trond Myklebust

SUNRPC/NFS: Add Kbuild dependencies for NFS_DEBUG/RPC_DEBUG

2012-03-20T17:08:26+00:00

This allows us to turn on/off the dprintk() debugging interfaces for those distributions that don't ship the 'rpcdebug' utility. It also allows us to add Kbuild dependencies. Specifically, we already know that dprintk() in general relies on CONFIG_SYSCTL. Now it turns out that the NFS dprintks depend on CONFIG_CRC32 after we added support for the filehandle hash. Reported-by: Paul Gortmaker Signed-off-by: Trond Myklebust

NFS: Revert NFSROOT default mount options

2011-05-27T21:42:47+00:00

Marek Belisko reports that recent attempts to fix regressions in NFSROOT have broken his configuration: > After update from 2.6.38-rc8 to 2.6.38 is mounting rootfs over nfs not possible. > Log: > VFS: Mounted root (nfs filesystem) on device 0:14. > Freeing init memory: 132K > nfs: server 10.146.1.21 not responding, still trying > nfs: server 10.146.1.21 not responding, still trying > > This is never ending. I make short bisect (not too much commits > between versions) > and bad commit was reported: 53d4737580535e073963b91ce87d4216e434fab5 > > NFS: NFSROOT should default to "proto=udp" > > I've tested on mini2440 board (DM9000, static IP). > Is there some missing option or something else to be checked? An examination of a network trace captured during the failure shows that the mount is actually succeeding, but that the client is not seeing READ replies larger than 16KB. This could be a local packet filtering issue on the client, but we didn't troubleshoot this further because of the reported "git bisect" result. Last fall we removed the ad hoc mount option parser in fs/nfs/nfsroot.c in favor of using the main parser in fs/nfs/super.c (see commit 56463e50 "NFS: Use super.c for NFSROOT mount option parsing"). That commit changed the default NFSROOT mount options to be the same as those employed by user space mounts. As it turns out, these new default mount options are not tolerated by many embedded systems. So far these problems have been due to specific behavior of certain embedded NICs. The NFS community does not have such hardware on hand for running tests. Commit 53d47375 recently introduced a clean way to specify default mount options for NFSROOT, so we can now easily restore the traditional defaults for NFSROOT: vers=2,udp,rsize=4096,wsize=4096 This should revert the new default NFSROOT mount options introduced with commit 56463e50. Tested-by: Marek Belisto Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

NFS: NFSROOT should default to "proto=udp"

2011-03-11T20:38:07+00:00

There have been a number of recent reports that NFSROOT is no longer working with default mount options, but fails only with certain NICs. Brian Downing bisected to commit 56463e50 "NFS: Use super.c for NFSROOT mount option parsing". Among other things, this commit changes the default mount options for NFSROOT to use TCP instead of UDP as the underlying transport. TCP seems less able to deal with NICs that are slow to initialize. The system logs that have accompanied reports of problems all show that NFSROOT attempts to establish a TCP connection before the NIC is fully initialized, and thus the TCP connection attempt fails. When a TCP connection attempt fails during a mount operation, the NFS stack needs to fail the operation. Usually user space knows how and when to retry it. The network layer does not report a distinct error code for this particular failure mode. Thus, there isn't a clean way for the RPC client to see that it needs to retry in this case, but not in others. Because NFSROOT is used in some environments where it is not possible to update the kernel command line to specify "udp", the proper thing to do is change NFSROOT to use UDP by default, as it did before commit 56463e50. To make it easier to see how to change default mount options for NFSROOT and to distinguish default settings from mandatory settings, I've adjusted a couple of areas to document the specifics. root_nfs_cat() is also modified to deal with commas properly when concatenating strings containing mount option lists. This keeps root_nfs_cat() call sites simpler, now that we may be concatenating multiple mount option strings. Tested-by: Brian Downing Tested-by: Mark Brown Signed-off-by: Chuck Lever Cc: # 2.6.37 Signed-off-by: Trond Myklebust

NFS: Fix a compile issue in nfs_root

2010-10-26T17:56:42+00:00

Stephen Rothwell reports: > /home/test/linux-2.6/fs/nfs/nfsroot.c: In function 'nfs_root_debug': > /home/test/linux-2.6/fs/nfs/nfsroot.c:110:2: error: 'nfs_debug' > undeclared (first use in this function) > /home/test/linux-2.6/fs/nfs/nfsroot.c:110:2: note: each undeclared > identifier is reported only once for each function it appears in > make[3]: *** [fs/nfs/nfsroot.o] Error 1 > make[2]: *** [fs/nfs] Error 2 > make[1]: *** [fs] Error 2 > make: *** [sub-make] Error 2 Which is caused by commit 306a075362a288683f6346185f97dd0e06df19da (NFS: Allow NFSROOT debugging messages to be enabled dynamically) Fix is to disable this code when RPC_DEBUG is disabled. Reported-by: Zimny Lech Tested-by: Ingo Molnar Signed-off-by: Trond Myklebust

NFS: Allow NFSROOT debugging messages to be enabled dynamically

2010-09-17T14:54:37+00:00

As a convenience, introduce a kernel command line option to enable NFSROOT debugging messages. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

NFS: Clean up nfsroot.c

2010-09-17T14:54:37+00:00

Clean up: now that mount option parsing for nfsroot is handled in fs/nfs/super.c, remove code in fs/nfs/nfsroot.c that is no longer used. This includes code that constructs the legacy nfs_mount_data structure, and code that does a MNT call to the server. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

NFS: Use super.c for NFSROOT mount option parsing

2010-09-17T14:54:37+00:00

Replace duplicate code in NFSROOT for mounting an NFS server on '/' with logic that uses the existing mainline text-based logic in the NFS client. Add documenting comments where appropriate. Note that this means NFSROOT mounts now use the same default settings as v2/v3 mounts done via mount(2) from user space. vers=3,tcp,rsize=,wsize= As before, however, no version/protocol negotiation with the server is done. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

NFS: Clean up NFSROOT command line parsing

2010-09-17T14:54:37+00:00

Clean up: To reduce confusion, rename nfs_root_name as nfs_root_parms, as this buffer contains more than just the name of the remote server. Introduce documenting comments around nfs_root_setup(). Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

nfs: include space for the NUL in root path

2010-07-30T19:33:39+00:00

In root_nfs_name() it does the following: if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) { printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n"); return -1; } sprintf(nfs_export_path, buf, cp); In the original code if (strlen(buf) + strlen(cp) == NFS_MAXPATHLEN) then the sprintf() would lead to an overflow. Generally the rest of the code assumes that the path can have NFS_MAXPATHLEN (1024) characters and a NUL terminator so the fix is to add space to the nfs_export_path[] buffer. Signed-off-by: Dan Carpenter Signed-off-by: Trond Myklebust