On 04/08/2011 07:16 AM, Sean Finney wrote: > Previously, when writing to /proc/net/rpc/*/channel, if a cache line > were larger than the default buffer size (likely 1024 bytes), mountd > and svcgssd would split writes into a number of buffer-sized writes. > Each of these writes would get an EINVAL error back from the kernel > procfs handle (it expects line-oriented input and does not account for > multiple/split writes), and no cache update would occur. > > When such behavior occurs, NFS clients depending on mountd to finish > the cache operation would block/hang, or receive EPERM, depending on > the context of the operation. This is likely to happen if a user is a > member of a large (~100-200) number of groups. > > Instead, every fopen() on the procfs files in question is followed by > a call to setvbuf(), using a per-file dedicated buffer of > RPC_CHAN_BUF_SIZE length. > > Really, mountd should not be using stdio-style buffered file operations > on files in /proc to begin with. A better solution would be to use > internally managed buffers and calls to write() instead of these stdio > calls, but that would be a more extensive change; so this is proposed > as a quick and not-so-dirty fix in the meantime. > > Signed-off-by: Sean Finney <sean.finney@xxxxxxxxxxxxxxxx> The same with this one... Committed! steved. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
