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linux-kernel: [PATCH 00/27] Permit filesystem local caching

[PATCH 00/27] Permit filesystem local caching

From: David Howells <dhowells_at_nospam>
Date: Wed Jan 23 2008 - 00:43:45 GMT

These patches add local caching for network filesystems such as NFS.

The patches can roughly be broken down into a number of sets:

(*) 01-keys-inc-payload.diff
(*) 02-keys-search-keyring.diff
(*) 03-keys-callout-blob.diff
Three patches to the keyring code made to help the CIFS people. Included because of patches 05-08.

(*) 04-keys-get-label.diff
A patch to allow the security label of a key to be retrieved. Included because of patches 05-08.
(*) 05-security-current-fsugid.diff
(*) 06-security-separate-task-bits.diff
(*) 07-security-subjective.diff
(*) 08-security-secctx2secid.diff
(*) 09-security-additional-classes.diff
(*) 10-security-kernel_service-class.diff
(*) 11-security-kernel-service.diff
(*) 12-security-nfsd.diff
Patches to permit the subjective security of a task to be overridden. All the security details in task_struct are decanted into a new struct that task_struct then has two pointers two: one that defines the objective security of that task (how other tasks may affect it) and one that defines the subjective security (how it may affect other objects). Note that I have dropped the idea of struct cred for the moment. With the amount of stuff that was excluded from it, it wasn't actually any use to me. However, it can be added later. Required for cachefiles.
(*) 13-release-page.diff
(*) 14-fscache-page-flags.diff
(*) 15-add_wait_queue_tail.diff
(*) 16-fscache.diff

      Patches to provide a local caching facility for network filesystems.

(*) 17-cachefiles-ia64.diff
(*) 18-cachefiles-ext3-f_mapping.diff
(*) 19-cachefiles-write.diff
(*) 20-cachefiles-monitor.diff
(*) 21-cachefiles-export.diff
(*) 22-cachefiles.diff
Patches to provide a local cache in a directory of an already mounted filesystem.
(*) 23-nfs-memleak.diff
(*) 24-fscache-nfs.diff
(*) 25-fscache-nfs-mount.diff
(*) 26-fscache-nfs-display.diff
(*) 27-fscache-nfs-persb.diff
Patches to provide NFS with local caching. The fifth of these patches makes caching configurable per superblock.

I've updated the patches to compile on as many arches I can get compilers for and can get to compile. However, for patch 06, the sparc and alpha arches need some asm work as they access security information from asm code, using asm-offsets to calculate the offset.

The SELinux base code will also need updating to have the security class, lest the following error appear in dmesg:

        context_struct_compute_av: unrecognized class 69

I've provided a patch to make NFSd use task_security and current->act_as to change its security settings.

I've also renamed the accessors for the PG_fscache and PG_fscache_write bits in page-flags.h, pagemap.h and filemap.c (they subclass PG_private_2 and PG_owner_priv_2 so these are the accessors in the main headers). I've then wrapped them in fscache.h. -- A tarball of the patches is available at: To use this version of CacheFiles, the cachefilesd-0.9 is also required. It is available as an SRPM: Or as individual bits: The .fc, .if and .te files are for manipulating SELinux. David - To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to More majordomo info at