From a40dc6cc2e121abcbd1b22583ef5447763df510c Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 10 Jan 2012 09:12:55 -0800 Subject: ceph: enable/disable dentry complete flags via mount option Enable/disable use of the dentry dir 'complete' flag via a mount option. This lets the admin control whether ceph uses the dcache to satisfy negative lookups or readdir when it has the entire directory contents in its cache. This is purely a performance optimization; correctness is guaranteed whether it is enabled or not. Reviewed-by: Christoph Hellwig Signed-off-by: Sage Weil --- Documentation/filesystems/ceph.txt | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'Documentation/filesystems') diff --git a/Documentation/filesystems/ceph.txt b/Documentation/filesystems/ceph.txt index 763d8ebbbebd..d6030aa33376 100644 --- a/Documentation/filesystems/ceph.txt +++ b/Documentation/filesystems/ceph.txt @@ -119,12 +119,20 @@ Mount Options must rely on TCP's error correction to detect data corruption in the data payload. - noasyncreaddir - Disable client's use its local cache to satisfy readdir - requests. (This does not change correctness; the client uses - cached metadata only when a lease or capability ensures it is - valid.) + dcache + Use the dcache contents to perform negative lookups and + readdir when the client has the entire directory contents in + its cache. (This does not change correctness; the client uses + cached metadata only when a lease or capability ensures it is + valid.) + + nodcache + Do not use the dcache as above. This avoids a significant amount of + complex code, sacrificing performance without affecting correctness, + and is useful for tracking down bugs. + noasyncreaddir + Do not use the dcache as above for readdir. More Information ================ -- cgit v1.2.3-59-g8ed1b