linux-sg2042/fs
Dave Chinner d2e448d5fd xfs: add CRC protection to remote attributes
There are two ways of doing this - the first is to add a CRC to the
remote attribute entry in the attribute block. The second is to
treat them similar to the remote symlink, where each fragment has
it's own header and identifies fragment location in the attribute.

The problem with the CRC in the remote attr entry is that we cannot
identify the owner of the metadata from the metadata blocks
themselves, or where the blocks fit into the remote attribute. The
down side to this approach is that we never know when the attribute
has been read from disk or not and so we have to verify it every
time it is read, and we must calculate it during the create
transaction and log it. We do not log CRCs for any other metadata,
and so this creates a unique set of coherency problems that, in
general, are best avoided.

Adding an identifying header to each allocated block allows us to
identify each fragment and where in the attribute it is located. It
enables us to rebuild the remote attribute from just the raw blocks
containing the attribute. It also provides us to do per-block CRCs
verification at IO time rather than during the transaction context
that creates it or every time it is read into a user buffer. Hence
it avoids all the problems that an external, logged CRC has, and
provides all the benefits of self identifying metadata.

The only complexity is that we have to add a header per fragment,
and we don't know how many fragments will be needed prior to
allocations. If we take the symlink example, the header is 56 bytes
and hence for a 4k block size filesystem, in the worst case 16
headers requires 1 extra block for the 64k attribute data. For 512
byte filesystems the worst case is an extra block for every 9
fragments (i.e. 16 extra blocks in the worse case). This will be
very rare and so it's not really a major concern.

Because allocation is done in two steps - the first finds a hole
large enough in the attribute file, the second does the allocation -
we only need to find a hole big enough for a worst case allocation.
We only need to allocate enough extra blocks for number of headers
required by the fragments, and we can calculate that as we go....

Hence it really only makes sense to use the same model as for
symlinks - it doesn't add that much complexity, does not require an
attribute tree format change, and does not require logging
calculated CRC values.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-04-27 12:58:53 -05:00
..
9p Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-03-03 13:23:03 -08:00
adfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
affs hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
afs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
autofs4 autofs4 - autofs4_catatonic_mode(): remove redundant null check on kfree() 2013-03-01 12:04:39 -08:00
befs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
bfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2013-03-03 13:13:20 -08:00
cachefiles FS-Cache: Mark cancellation of in-progress operation 2012-12-20 22:34:00 +00:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2013-02-28 17:43:09 -08:00
cifs Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6 2013-03-01 12:05:13 -08:00
coda Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
configfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
cramfs new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
debugfs Merge 3.9-rc4 into driver-core-next 2013-01-17 19:48:18 -08:00
devpts userns: Allow the userns root to mount of devpts 2013-01-26 22:22:21 -08:00
dlm hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
ecryptfs hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
efs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
exofs new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
exportfs hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
ext2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
ext3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
ext4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-03-03 13:23:03 -08:00
f2fs more file_inode() open-coded instances 2013-02-27 16:59:05 -05:00
fat hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
freevxfs new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
fscache hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
fuse more file_inode() open-coded instances 2013-02-27 16:59:05 -05:00
gfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
hfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
hfsplus hfsplus: fix issue with unzeroed unused b-tree nodes 2013-02-27 19:10:10 -08:00
hostfs hostfs: directory methods have no business in non-directory inode_operations 2013-02-22 23:31:37 -05:00
hpfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
hppfs new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
hugetlbfs hugetlb_file_setup(): use d_alloc_pseudo() 2013-02-26 02:45:52 -05:00
isofs fs: encode_fh: return FILEID_INVALID if invalid fid_type 2013-02-26 02:46:10 -05:00
jbd jbd: don't wake kjournald unnecessarily 2013-01-14 22:50:45 +01:00
jbd2 jbd2: fix ERR_PTR dereference in jbd2__journal_start 2013-03-02 17:08:46 -05:00
jffs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
jfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
lockd Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux 2013-02-28 18:02:55 -08:00
logfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
minix new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
ncpfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
nfs NFS client bugfixes for Linux 3.9 2013-03-02 16:46:07 -08:00
nfs_common nfs_common: Update the translation between nfsv3 acls linux posix acls 2013-02-13 06:15:14 -08:00
nfsd Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux 2013-02-28 18:02:55 -08:00
nilfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
nls
notify hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
ntfs new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
ocfs2 hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
omfs new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
openpromfs new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
proc fs/proc/vmcore.c: put if tests in the top of the while loop to reduce duplication 2013-02-27 19:10:11 -08:00
pstore A few fixes to reduce places where pstore might hang 2013-02-21 09:38:18 -08:00
qnx4 new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
qnx6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
quota quota: Use the pre-processor to compile out quotactl_cmd_write when !CONFIG_BLOCK 2012-12-13 16:33:24 +01:00
ramfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
reiserfs fs: encode_fh: return FILEID_INVALID if invalid fid_type 2013-02-26 02:46:10 -05:00
romfs new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
squashfs new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
sysfs hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
sysv new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
ubifs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
udf Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
ufs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
xfs xfs: add CRC protection to remote attributes 2013-04-27 12:58:53 -05:00
Kconfig fuse: Move CUSE Kconfig entry from fs/Kconfig into fs/fuse/Kconfig 2013-01-17 13:08:45 +01:00
Kconfig.binfmt
Makefile f2fs: update Kconfig and Makefile 2012-12-11 13:43:42 +09:00
aio.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
anon_inodes.c get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero 2013-02-26 02:46:11 -05:00
attr.c userns: Allow chown and setgid preservation 2012-11-20 04:17:24 -08:00
bad_inode.c lseek: the "whence" argument is called "whence" 2012-12-17 17:15:12 -08:00
binfmt_aout.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
binfmt_elf.c ImgTec Meta architecture changes for v3.9-rc1 2013-03-03 12:06:09 -08:00
binfmt_elf_fdpic.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
binfmt_em86.c exec: use -ELOOP for max recursion depth 2012-12-17 17:15:23 -08:00
binfmt_flat.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
binfmt_misc.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
binfmt_script.c exec: do not leave bprm->interp on stack 2012-12-20 17:40:19 -08:00
binfmt_som.c get rid of pt_regs argument of ->load_binary() 2012-11-28 21:53:38 -05:00
bio-integrity.c
bio.c block: add missing block_bio_complete() tracepoint 2013-01-14 15:00:36 +01:00
block_dev.c Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-block 2013-02-28 12:52:24 -08:00
buffer.c Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-block 2013-02-28 12:52:24 -08:00
char_dev.c
compat.c switch timerfd compat syscalls to COMPAT_SYSCALL_DEFINE 2013-02-03 15:09:25 -05:00
compat_binfmt_elf.c
compat_ioctl.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
coredump.c coredump: remove redundant defines for dumpable states 2013-02-27 19:10:11 -08:00
coredump.h
dcache.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
dcookies.c
direct-io.c fs: Fix possible use-after-free with AIO 2013-02-22 23:31:36 -05:00
drop_caches.c
eventfd.c fs, eventfd: add procfs fdinfo helper 2012-12-17 17:15:27 -08:00
eventpoll.c epoll: prevent missed events on EPOLL_CTL_MOD 2013-01-02 09:16:43 -08:00
exec.c coredump: remove redundant defines for dumpable states 2013-02-27 19:10:11 -08:00
fcntl.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
fhandle.c Merge branch 'for-3.8' of git://linux-nfs.org/~bfields/linux 2012-12-20 14:04:11 -08:00
fifo.c
file.c locking: Various static lock initializer fixes 2013-02-19 08:42:45 +01:00
file_table.c cache the value of file_inode() in struct file 2013-03-01 19:48:30 -05:00
filesystems.c
fs-writeback.c 2 writeback fixes 2013-02-28 13:21:44 -08:00
fs_struct.c constify path_get/path_put and fs_struct.c stuff 2013-03-01 23:51:07 -05:00
generic_acl.c
inode.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
internal.h constify path_get/path_put and fs_struct.c stuff 2013-03-01 23:51:07 -05:00
ioctl.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
ioprio.c
libfs.c vfs: drop vmtruncate 2012-12-20 18:46:29 -05:00
locks.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
mbcache.c
mount.h proc: Usable inode numbers for the namespace file descriptors. 2012-11-20 04:19:49 -08:00
mpage.c
namei.c constify path_get/path_put and fs_struct.c stuff 2013-03-01 23:51:07 -05:00
namespace.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
no-block.c
open.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-03-03 13:23:03 -08:00
pipe.c fs: Preserve error code in get_empty_filp(), part 2 2013-02-22 23:31:32 -05:00
pnode.c
pnode.h vfs: Only support slave subtrees across different user namespaces 2012-11-19 05:59:20 -08:00
posix_acl.c
proc_namespace.c
read_write.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-03-02 08:34:06 -08:00
read_write.h
readdir.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
select.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
seq_file.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-03-03 13:23:03 -08:00
signalfd.c fs, epoll: add procfs fdinfo helper 2012-12-17 17:15:27 -08:00
splice.c export kernel_write(), convert open-coded instances 2013-02-26 02:46:11 -05:00
stack.c
stat.c switch vfs_getattr() to struct path 2013-02-26 02:46:08 -05:00
statfs.c vfs: fix user_statfs to retry once on ESTALE errors 2012-12-20 18:50:07 -05:00
super.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
sync.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
timerfd.c compat: restore timerfd settime and gettime compat syscalls 2013-03-02 09:35:13 -05:00
utimes.c vfs: allow utimensat() calls to retry once on an ESTALE error 2012-12-20 18:50:08 -05:00
xattr.c vfs: make lremovexattr retry once on ESTALE error 2012-12-20 18:50:11 -05:00
xattr_acl.c