From: "J. Bruce Fields" <bfields@xxxxxxxxxx> Previous posting: http://mid.gmane.org/<1350424897-26894-1-git-send-email-bfields@xxxxxxxxxx> This patch series implements read delegations, which allow NFSv4 clients to perform read opens without contacting the server, by promising to call back to clients before modifying the data, metadata, or set of links pointing to a file. The main recent change was in response to review from Linus, who didn't want us to hang under directory i_mutex's on timeouts communicating with unresponsive clients. So, this version of the series drops the i_mutex before waiting. The logic ends up looking something like: acquire locks look up inode test for delegation; if found: take reference on inode release locks wait for delegation break drop reference on inode retry The initial test for a delegation happens after the lock on the delegated inode is acquired, but additional directory mutexes may have been acquired further up the call stack. I therefore add a "struct inode **" argument to any intervening functions, which we use to pass the inode back up to the caller in the case it needs to wait for the delegation to be broken. I also allow callers to pass in NULL for the "struct inode **" argument to indicate they'd rather just fail than wait for a delegation. For example, as long as ecryptfs isn't exportable I assume they'd rather not see retry logic there that they won't use. But I may have misjudged in some of these cases. Maybe there's a simpler approach. Happy for any feedback. That aside, I don't know of any bugs at this point, so as far as I'm concerned it's ready for 3.9. --b. J. Bruce Fields (12): vfs: pull ext4's double-i_mutex-locking into common code vfs: don't use PARENT/CHILD lock classes for non-directories vfs: rename I_MUTEX_QUOTA now that it's not used for quotas vfs: take i_mutex on renamed file locks: introduce new FL_DELEG lock flag locks: implement delegations namei: minor vfs_unlink cleanup locks: break delegations on unlink locks: helper functions for delegation breaking locks: break delegations on rename locks: break delegations on link locks: break delegations on any attribute modification Documentation/filesystems/directory-locking | 31 ++++++++--- drivers/base/devtmpfs.c | 6 +- fs/attr.c | 5 +- fs/cachefiles/interface.c | 4 +- fs/cachefiles/namei.c | 4 +- fs/ecryptfs/inode.c | 6 +- fs/ext4/move_extent.c | 40 +------------- fs/hpfs/namei.c | 2 +- fs/inode.c | 35 +++++++++++- fs/locks.c | 51 +++++++++++++---- fs/namei.c | 79 +++++++++++++++++++++------ fs/nfsd/nfs4state.c | 2 +- fs/nfsd/vfs.c | 14 +++-- fs/open.c | 21 +++++-- fs/utimes.c | 9 ++- include/linux/fs.h | 72 ++++++++++++++++++++---- ipc/mqueue.c | 2 +- 17 files changed, 271 insertions(+), 112 deletions(-) -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
