Messages in this thread | | | From | (Eric W. Biederman) | Date | Mon, 14 Apr 2014 00:38:47 -0700 | Subject | [RFC][PATCH 0/4] No I/O from mntput |
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There are a lot of ways we could approach this, and I sat down and wrote the simplest variant I could think of, so hopefully there are not silly bugs that get overlooked.
The code move all cleanup from mntput that would do filesystem I/O into work queues.
The code waits in mntput for that I/O to complete if we wait today.
The code has been tested and it works, and it succeeds in running deactivate_super in a stack from with just short of 7500 bytes free. 7500 bytes should be enough for anybody!
I want to double check that I am using work queues correctly, they used to be deadlock prone, and sleep on everything before I commit to a final version but this version is probably good enough.
I may be going overboard in the case where we auto close BSD accounting files, but at this point I figure better safe than sorry.
Eric W. Biederman (4): vfs: Remove useless loop in mntput_no_expire vfs: Move autoclose of BSD accounting into a work queue vfs: In mntput run deactivate_super on a shallow stack. vfs: Block intuitively in the case of BSD accounting files
fs/mount.h | 14 +++++++++++--- fs/namespace.c | 43 +++++++++++++++++++++++++++++++++++-------- kernel/acct.c | 25 ++++++++++++++++++++----- 3 files changed, 66 insertions(+), 16 deletions(-)
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