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path: root/fs/ecryptfs/kthread.c
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2011-04-25eCryptfs: Add reference counting to lower filesTyler Hicks
For any given lower inode, eCryptfs keeps only one lower file open and multiplexes all eCryptfs file operations through that lower file. The lower file was considered "persistent" and stayed open from the first lookup through the lifetime of the inode. This patch keeps the notion of a single, per-inode lower file, but adds reference counting around the lower file so that it is closed when not currently in use. If the reference count is at 0 when an operation (such as open, create, etc.) needs to use the lower file, a new lower file is opened. Since the file is no longer persistent, all references to the term persistent file are changed to lower file. Locking is added around the sections of code that opens the lower file and assign the pointer in the inode info, as well as the code the fputs the lower file when all eCryptfs users are done with it. This patch is needed to fix issues, when mounted on top of the NFSv3 client, where the lower file is left silly renamed until the eCryptfs inode is destroyed. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2010-08-27ecryptfs: properly mark init functionsJerome Marchand
Some ecryptfs init functions are not prefixed by __init and thus not freed after initialization. This patch saved about 1kB in ecryptfs module. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-09-23eCryptfs: Check for O_RDONLY lower inodes when opening lower filesTyler Hicks
If the lower inode is read-only, don't attempt to open the lower file read/write and don't hand off the open request to the privileged eCryptfs kthread for opening it read/write. Instead, only try an unprivileged, read-only open of the file and give up if that fails. This patch fixes an oops when eCryptfs is mounted on top of a read-only mount. Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Eric Sandeen <esandeen@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: ecryptfs-devel@lists.launchpad.net Cc: stable <stable@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2008-11-14CRED: Pass credentials through dentry_open()David Howells
Pass credentials through dentry_open() so that the COW creds patch can have SELinux's flush_unauthorized_files() pass the appropriate creds back to itself when it opens its null chardev. The security_dentry_open() call also now takes a creds pointer, as does the dentry_open hook in struct security_operations. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Signed-off-by: James Morris <jmorris@namei.org>
2008-07-24eCryptfs: Privileged kthread for lower file opensMichael Halcrow
eCryptfs would really like to have read-write access to all files in the lower filesystem. Right now, the persistent lower file may be opened read-only if the attempt to open it read-write fails. One way to keep from having to do that is to have a privileged kthread that can open the lower persistent file on behalf of the user opening the eCryptfs file; this patch implements this functionality. This patch will properly allow a less-privileged user to open the eCryptfs file, followed by a more-privileged user opening the eCryptfs file, with the first user only being able to read and the second user being able to both read and write. eCryptfs currently does this wrong; it will wind up calling vfs_write() on a file that was opened read-only. This is fixed in this patch. Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>