History log of /linux/fs/xfs/libxfs/xfs_attr_remote.h (Results 126 – 146 of 146)
Revision (<<< Hide revision tags) (Show revision tags >>>) Date Author Comments
Revision tags: v5.6-rc1
# 91f1a956 30-Jan-2020 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'xfs-5.6-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Darrick Wong:
"In this release we clean out the last of the old 32-bit timestamp
code, fix a num

Merge tag 'xfs-5.6-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Darrick Wong:
"In this release we clean out the last of the old 32-bit timestamp
code, fix a number of bugs and memory corruptions on 32-bit platforms,
and a refactoring of some of the extended attribute code.

I think I'll be back next week with some refactoring of how the XFS
buffer code returns error codes, however I prefer to hold onto that
for another week to let it soak a while longer

Summary:

- Get rid of compat_time_t

- Convert time_t to time64_t in quota code

- Remove shadow variables

- Prevent ATTR_ flag misuse in the attrmulti ioctls

- Clean out strlen in the attr code

- Remove some bogus asserts

- Fix various file size limit calculation errors with 32-bit kernels

- Pack xfs_dir2_sf_entry_t to fix build errors on arm oabi

- Fix nowait inode locking calls for directio aio reads

- Fix memory corruption bugs when invalidating remote xattr value
buffers

- Streamline remote attr value removal

- Make the buffer log format size consistent across platforms

- Strengthen buffer log format size checking

- Fix messed up return types of xfs_inode_need_cow

- Fix some unused variable warnings"

* tag 'xfs-5.6-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (24 commits)
xfs: remove unused variable 'done'
xfs: fix uninitialized variable in xfs_attr3_leaf_inactive
xfs: change return value of xfs_inode_need_cow to int
xfs: check log iovec size to make sure it's plausibly a buffer log format
xfs: make struct xfs_buf_log_format have a consistent size
xfs: complain if anyone tries to create a too-large buffer log item
xfs: clean up xfs_buf_item_get_format return value
xfs: streamline xfs_attr3_leaf_inactive
xfs: fix memory corruption during remote attr value buffer invalidation
xfs: refactor remote attr value buffer invalidation
xfs: fix IOCB_NOWAIT handling in xfs_file_dio_aio_read
xfs: Add __packed to xfs_dir2_sf_entry_t definition
xfs: fix s_maxbytes computation on 32-bit kernels
xfs: truncate should remove all blocks, not just to the end of the page cache
xfs: introduce XFS_MAX_FILEOFF
xfs: remove bogus assertion when online repair isn't enabled
xfs: Remove all strlen in all xfs_attr_* functions for attr names.
xfs: fix misuse of the XFS_ATTR_INCOMPLETE flag
xfs: also remove cached ACLs when removing the underlying attr
xfs: reject invalid flags combinations in XFS_IOC_ATTRMULTI_BY_HANDLE
...

show more ...


Revision tags: v5.5, v5.5-rc7, v5.5-rc6
# 8edbb26b 08-Jan-2020 Darrick J. Wong <darrick.wong@oracle.com>

xfs: refactor remote attr value buffer invalidation

Hoist the code that invalidates remote extended attribute value buffers
into a separate helper function. This prepares us for a memory
corruption

xfs: refactor remote attr value buffer invalidation

Hoist the code that invalidates remote extended attribute value buffers
into a separate helper function. This prepares us for a memory
corruption fix in the next patch.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

show more ...


Revision tags: v5.5-rc5, v5.5-rc4, v5.5-rc3, v5.5-rc2, v5.5-rc1, v5.4, v5.4-rc8, v5.4-rc7, v5.4-rc6, v5.4-rc5, v5.4-rc4, v5.4-rc3, v5.4-rc2, v5.4-rc1, v5.3, v5.3-rc8, v5.3-rc7, v5.3-rc6, v5.3-rc5, v5.3-rc4, v5.3-rc3, v5.3-rc2, v5.3-rc1, v5.2, v5.2-rc7, v5.2-rc6, v5.2-rc5, v5.2-rc4, v5.2-rc3, v5.2-rc2, v5.2-rc1, v5.1, v5.1-rc7, v5.1-rc6, v5.1-rc5, v5.1-rc4, v5.1-rc3, v5.1-rc2, v5.1-rc1, v5.0, v5.0-rc8, v5.0-rc7, v5.0-rc6, v5.0-rc5, v5.0-rc4, v5.0-rc3
# 3eb66e91 14-Jan-2019 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge tag 'v4.20' into for-linus

Sync with mainline to get linux/overflow.h among other things.


# 4116941b 14-Jan-2019 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge tag 'v4.20' into next

Merge with mainline to bring in the new APIs.


Revision tags: v5.0-rc2, v5.0-rc1, v4.20, v4.20-rc7, v4.20-rc6, v4.20-rc5, v4.20-rc4, v4.20-rc3, v4.20-rc2, v4.20-rc1, v4.19, v4.19-rc8, v4.19-rc7, v4.19-rc6, v4.19-rc5, v4.19-rc4, v4.19-rc3, v4.19-rc2, v4.19-rc1, v4.18, v4.18-rc8, v4.18-rc7
# c74a7469 23-Jul-2018 Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-next into drm-intel-next-queued

We need a backmerge to get DP_DPCD_REV_14 before we push other
i915 changes to dinq that could break compilation.

Signed-off-by: Rodrigo Vivi <rodrigo.

Merge drm/drm-next into drm-intel-next-queued

We need a backmerge to get DP_DPCD_REV_14 before we push other
i915 changes to dinq that could break compilation.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

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# 415d2b33 20-Aug-2018 Jiri Kosina <jkosina@suse.cz>

Merge branch 'for-4.19/cougar' into for-linus

New device support for hid-cougar


# a3479c7f 24-Jul-2018 Andreas Gruenbacher <agruenba@redhat.com>

Merge branch 'iomap-write' into linux-gfs2/for-next

Pull in the gfs2 iomap-write changes: Tweak the existing code to
properly support iomap write and eliminate an unnecessary special case
in gfs2_bl

Merge branch 'iomap-write' into linux-gfs2/for-next

Pull in the gfs2 iomap-write changes: Tweak the existing code to
properly support iomap write and eliminate an unnecessary special case
in gfs2_block_map. Implement iomap write support for buffered and
direct I/O. Simplify some of the existing code and eliminate code that
is no longer used:

gfs2: Remove gfs2_write_{begin,end}
gfs2: iomap direct I/O support
gfs2: gfs2_extent_length cleanup
gfs2: iomap buffered write support
gfs2: Further iomap cleanups

This is based on the following changes on the xfs 'iomap-4.19-merge'
branch:

iomap: add private pointer to struct iomap
iomap: add a page_done callback
iomap: generic inline data handling
iomap: complete partial direct I/O writes synchronously
iomap: mark newly allocated buffer heads as new
fs: factor out a __generic_write_end helper

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

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# d5e748ff 23-Jul-2018 Benjamin Herrenschmidt <benh@kernel.crashing.org>

Merge remote-tracking branch 'gpio/ib-aspeed' into upstream-ready

Merge the GPIO tree "ib-aspeed" topic branch which contains pre-requisites
for subsequent changes. This branch is also in gpio "next

Merge remote-tracking branch 'gpio/ib-aspeed' into upstream-ready

Merge the GPIO tree "ib-aspeed" topic branch which contains pre-requisites
for subsequent changes. This branch is also in gpio "next".

show more ...


Revision tags: v4.18-rc6, v4.18-rc5, v4.18-rc4, v4.18-rc3
# 6b16f5d1 28-Jun-2018 Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Merge tag 'v4.18-rc2' of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into fbdev-for-next

Linux 4.18-rc2


# 57b54d74 25-Jun-2018 James Morris <james.morris@microsoft.com>

Merge tag 'v4.18-rc2' into next-general

Merge to Linux 4.18-rc2 for security subsystem developers.


Revision tags: v4.18-rc2
# 7731b8bc 22-Jun-2018 Thomas Gleixner <tglx@linutronix.de>

Merge branch 'linus' into x86/urgent

Required to queue a dependent fix.


Revision tags: v4.18-rc1
# a205f0c9 12-Jun-2018 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'xfs-4.18-merge-10' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull more xfs updates from Darrick Wong:
"Here's the second round of patches for XFS for 4.18. Most of the
commits a

Merge tag 'xfs-4.18-merge-10' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull more xfs updates from Darrick Wong:
"Here's the second round of patches for XFS for 4.18. Most of the
commits are small cleanups, bug fixes, and continued strengthening of
metadata verifiers; the bulk of the diff is the conversion of the
fs/xfs/ tree to use SPDX tags.

This series has been run through a full xfstests run over the weekend
and through a quick xfstests run against this morning's master, with
no major failures reported.

Summary:

- Strengthen metadata checking to avoid ASSERTing on bad disk
contents

- Validate btree records that are being retrieved for clients

- Strengthen root inode verification

- Convert license blurbs to SPDX tags

- Enable changing DAX flag on directories

- Fix some writeback deadlocks in reflink

- Refactor out some old xfs helpers

- Move type verifiers to a separate file

- Fix some fuzzer crashes

- Various other bug fixes"

* tag 'xfs-4.18-merge-10' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (31 commits)
xfs: update incore per-AG inode count
xfs: replace do_mod with native operations
xfs: don't call xfs_da_shrink_inode with NULL bp
xfs: clean up MIN/MAX
xfs: move various type verifiers to common file
xfs: xfs_reflink_convert_cow() memory allocation deadlock
xfs: setup VFS i_rwsem lockdep state correctly
xfs: fix string handling in label get/set functions
xfs: convert to SPDX license tags
xfs: validate btree records on retrieval
xfs: push corruption -> ESTALE conversion to xfs_nfs_get_inode()
xfs: verify root inode more thoroughly
xfs: verify COW extent size hint is valid in inode verifier
xfs: verify extent size hint is valid in inode verifier
xfs: catch bad stripe alignment configurations
iomap: fsync swap files before iterating mappings
xfs: use xfs_trans_getsb in xfs_sync_sb_buf
xfs: don't assert on corrupted unlinked inode list
xfs: explicitly pass buffer size to xfs_corruption_error
xfs: don't assert when on-disk btree pointers are garbage
...

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# 0b61f8a4 06-Jun-2018 Dave Chinner <dchinner@redhat.com>

xfs: convert to SPDX license tags

Remove the verbose license text from XFS files and replace them
with SPDX tags. This does not change the license of any of the code,
merely refers to the common, up

xfs: convert to SPDX license tags

Remove the verbose license text from XFS files and replace them
with SPDX tags. This does not change the license of any of the code,
merely refers to the common, up-to-date license files in LICENSES/

This change was mostly scripted. fs/xfs/Makefile and
fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected
and modified by the following command:

for f in `git grep -l "GNU General" fs/xfs/` ; do
echo $f
cat $f | awk -f hdr.awk > $f.new
mv -f $f.new $f
done

And the hdr.awk script that did the modification (including
detecting the difference between GPL-2.0 and GPL-2.0+ licenses)
is as follows:

$ cat hdr.awk
BEGIN {
hdr = 1.0
tag = "GPL-2.0"
str = ""
}

/^ \* This program is free software/ {
hdr = 2.0;
next
}

/any later version./ {
tag = "GPL-2.0+"
next
}

/^ \*\// {
if (hdr > 0.0) {
print "// SPDX-License-Identifier: " tag
print str
print $0
str=""
hdr = 0.0
next
}
print $0
next
}

/^ \* / {
if (hdr > 1.0)
next
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
next
}

/^ \*/ {
if (hdr > 0.0)
next
print $0
next
}

// {
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
}

END { }
$

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

show more ...


Revision tags: v4.17, v4.17-rc7, v4.17-rc6, v4.17-rc5, v4.17-rc4, v4.17-rc3, v4.17-rc2, v4.17-rc1, v4.16, v4.16-rc7, v4.16-rc6, v4.16-rc5, v4.16-rc4, v4.16-rc3, v4.16-rc2, v4.16-rc1, v4.15, v4.15-rc9, v4.15-rc8, v4.15-rc7, v4.15-rc6, v4.15-rc5, v4.15-rc4, v4.15-rc3, v4.15-rc2, v4.15-rc1, v4.14, v4.14-rc8, v4.14-rc7, v4.14-rc6, v4.14-rc5, v4.14-rc4, v4.14-rc3, v4.14-rc2, v4.14-rc1, v4.13, v4.13-rc7, v4.13-rc6, v4.13-rc5, v4.13-rc4, v4.13-rc3, v4.13-rc2, v4.13-rc1, v4.12, v4.12-rc7, v4.12-rc6, v4.12-rc5, v4.12-rc4, v4.12-rc3, v4.12-rc2, v4.12-rc1, v4.11, v4.11-rc8, v4.11-rc7, v4.11-rc6, v4.11-rc5, v4.11-rc4, v4.11-rc3, v4.11-rc2, v4.11-rc1, v4.10, v4.10-rc8, v4.10-rc7, v4.10-rc6, v4.10-rc5, v4.10-rc4, v4.10-rc3, v4.10-rc2, v4.10-rc1, v4.9, v4.9-rc8, v4.9-rc7, v4.9-rc6, v4.9-rc5, v4.9-rc4, v4.9-rc3, v4.9-rc2, v4.9-rc1, v4.8, v4.8-rc8, v4.8-rc7, v4.8-rc6, v4.8-rc5, v4.8-rc4, v4.8-rc3, v4.8-rc2, v4.8-rc1, v4.7, v4.7-rc7, v4.7-rc6, v4.7-rc5, v4.7-rc4, v4.7-rc3, v4.7-rc2, v4.7-rc1, v4.6, v4.6-rc7, v4.6-rc6, v4.6-rc5, v4.6-rc4, v4.6-rc3, v4.6-rc2, v4.6-rc1, v4.5, v4.5-rc7, v4.5-rc6
# e5451c8f 23-Feb-2016 Laxman Dewangan <ldewangan@nvidia.com>

Merge remote-tracking branch 'linusw-gpio/for-next' into devm_gpiochip

Base for demv_gpiochip_add_data() and devm_gpiochip_remove().


Revision tags: v4.5-rc5, v4.5-rc4, v4.5-rc3, v4.5-rc2, v4.5-rc1, v4.4, v4.4-rc8, v4.4-rc7, v4.4-rc6, v4.4-rc5, v4.4-rc4, v4.4-rc3, v4.4-rc2, v4.4-rc1, v4.3, v4.3-rc7, v4.3-rc6, v4.3-rc5, v4.3-rc4, v4.3-rc3, v4.3-rc2, v4.3-rc1, v4.2, v4.2-rc8, v4.2-rc7, v4.2-rc6, v4.2-rc5, v4.2-rc4, v4.2-rc3, v4.2-rc2, v4.2-rc1, v4.1, v4.1-rc8, v4.1-rc7, v4.1-rc6, v4.1-rc5, v4.1-rc4, v4.1-rc3, v4.1-rc2, v4.1-rc1, v4.0, v4.0-rc7, v4.0-rc6, v4.0-rc5, v4.0-rc4, v4.0-rc3, v4.0-rc2, v4.0-rc1, v3.19, v3.19-rc7, v3.19-rc6, v3.19-rc5, v3.19-rc4, v3.19-rc3, v3.19-rc2, v3.19-rc1, v3.18, v3.18-rc7, v3.18-rc6, v3.18-rc5, v3.18-rc4, v3.18-rc3, v3.18-rc2, v3.18-rc1, v3.17, v3.17-rc7, v3.17-rc6, v3.17-rc5, v3.17-rc4, v3.17-rc3, v3.17-rc2, v3.17-rc1, v3.16, v3.16-rc7, v3.16-rc6, v3.16-rc5, v3.16-rc4, v3.16-rc3
# 84be0ffc 25-Jun-2014 Dave Chinner <dchinner@redhat.com>

libxfs: move header files

Move all the header files that are shared with userspace into
libxfs. This is done as one big chunk simpy to get it done quickly.

Signed-off-by: Dave Chinner <dchinner@red

libxfs: move header files

Move all the header files that are shared with userspace into
libxfs. This is done as one big chunk simpy to get it done quickly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

show more ...


Revision tags: v3.16-rc2, v3.16-rc1, v3.15, v3.15-rc8, v3.15-rc7, v3.15-rc6, v3.15-rc5, v3.15-rc4, v3.15-rc3, v3.15-rc2, v3.15-rc1, v3.14, v3.14-rc8, v3.14-rc7, v3.14-rc6, v3.14-rc5, v3.14-rc4, v3.14-rc3, v3.14-rc2, v3.14-rc1, v3.13, v3.13-rc8, v3.13-rc7, v3.13-rc6, v3.13-rc5, v3.13-rc4, v3.13-rc3, v3.13-rc2, v3.13-rc1, v3.12, v3.12-rc7, v3.12-rc6
# 57062787 14-Oct-2013 Dave Chinner <dchinner@redhat.com>

xfs: unify directory/attribute format definitions

The on-disk format definitions for the directory and attribute
structures are spread across 3 header files right now, only one of
which is dedicated

xfs: unify directory/attribute format definitions

The on-disk format definitions for the directory and attribute
structures are spread across 3 header files right now, only one of
which is dedicated to defining on-disk structures and their
manipulation (xfs_dir2_format.h). Pull all the format definitions
into a single header file - xfs_da_format.h - and switch all the
code over to point at that.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

show more ...


# 70a9883c 22-Oct-2013 Dave Chinner <dchinner@redhat.com>

xfs: create a shared header file for format-related information

All of the buffer operations structures are needed to be exported
for xfs_db, so move them all to a common location rather than
spread

xfs: create a shared header file for format-related information

All of the buffer operations structures are needed to be exported
for xfs_db, so move them all to a common location rather than
spreading them all over the place. They are verifying the on-disk
format, so while xfs_format.h might be a good place, it is not part
of the on disk format.

Hence we need to create a new header file that we centralise these
related definitions. Start by moving the bffer operations
structures, and then also move all the other definitions that have
crept into xfs_log_format.h and xfs_format.h as there was no other
shared header file to put them in.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

show more ...


Revision tags: v3.12-rc5, v3.12-rc4, v3.12-rc3, v3.12-rc2, v3.12-rc1, v3.11, v3.11-rc7, v3.11-rc6, v3.11-rc5, v3.11-rc4, v3.11-rc3, v3.11-rc2, v3.11-rc1, v3.10, v3.10-rc7, v3.10-rc6, v3.10-rc5, v3.10-rc4, v3.10-rc3
# 7bc0dc27 21-May-2013 Dave Chinner <dchinner@redhat.com>

xfs: rework remote attr CRCs

Note: this changes the on-disk remote attribute format. I assert
that this is OK to do as CRCs are marked experimental and the first
kernel it is included in has not yet

xfs: rework remote attr CRCs

Note: this changes the on-disk remote attribute format. I assert
that this is OK to do as CRCs are marked experimental and the first
kernel it is included in has not yet reached release yet. Further,
the userspace utilities are still evolving and so anyone using this
stuff right now is a developer or tester using volatile filesystems
for testing this feature. Hence changing the format right now to
save longer term pain is the right thing to do.

The fundamental change is to move from a header per extent in the
attribute to a header per filesytem block in the attribute. This
means there are more header blocks and the parsing of the attribute
data is slightly more complex, but it has the advantage that we
always know the size of the attribute on disk based on the length of
the data it contains.

This is where the header-per-extent method has problems. We don't
know the size of the attribute on disk without first knowing how
many extents are used to hold it. And we can't tell from a
mapping lookup, either, because remote attributes can be allocated
contiguously with other attribute blocks and so there is no obvious
way of determining the actual size of the atribute on disk short of
walking and mapping buffers.

The problem with this approach is that if we map a buffer
incorrectly (e.g. we make the last buffer for the attribute data too
long), we then get buffer cache lookup failure when we map it
correctly. i.e. we get a size mismatch on lookup. This is not
necessarily fatal, but it's a cache coherency problem that can lead
to returning the wrong data to userspace or writing the wrong data
to disk. And debug kernels will assert fail if this occurs.

I found lots of niggly little problems trying to fix this issue on a
4k block size filesystem, finally getting it to pass with lots of
fixes. The thing is, 1024 byte filesystems still failed, and it was
getting really complex handling all the corner cases that were
showing up. And there were clearly more that I hadn't found yet.

It is complex, fragile code, and if we don't fix it now, it will be
complex, fragile code forever more.

Hence the simple fix is to add a header to each filesystem block.
This gives us the same relationship between the attribute data
length and the number of blocks on disk as we have without CRCs -
it's a linear mapping and doesn't require us to guess anything. It
is simple to implement, too - the remote block count calculated at
lookup time can be used by the remote attribute set/get/remove code
without modification for both CRC and non-CRC filesystems. The world
becomes sane again.

Because the copy-in and copy-out now need to iterate over each
filesystem block, I moved them into helper functions so we separate
the block mapping and buffer manupulations from the attribute data
and CRC header manipulations. The code becomes much clearer as a
result, and it is a lot easier to understand and debug. It also
appears to be much more robust - once it worked on 4k block size
filesystems, it has worked without failure on 1k block size
filesystems, too.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

(cherry picked from commit ad1858d77771172e08016890f0eb2faedec3ecee)

show more ...


Revision tags: v3.10-rc2, v3.10-rc1, v3.9, v3.9-rc8, v3.9-rc7, v3.9-rc6
# d75afeb3 03-Apr-2013 Dave Chinner <dchinner@redhat.com>

xfs: add buffer types to directory and attribute buffers

Add buffer types to the buffer log items so that log recovery can
validate the buffers and calculate CRCs correctly after the buffers
are rec

xfs: add buffer types to directory and attribute buffers

Add buffer types to the buffer log items so that log recovery can
validate the buffers and calculate CRCs correctly after the buffers
are recovered.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

show more ...


# d2e448d5 03-Apr-2013 Dave Chinner <dchinner@redhat.com>

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

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>

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# 95920cd6 03-Apr-2013 Dave Chinner <dchinner@redhat.com>

xfs: split remote attribute code out

Adding CRC support to remote attributes adds a significant amount of
remote attribute specific code. Split the existing remote attribute
code out into it's own f

xfs: split remote attribute code out

Adding CRC support to remote attributes adds a significant amount of
remote attribute specific code. Split the existing remote attribute
code out into it's own file so that all the relevant remote
attribute code is in a single, easy to find place.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

show more ...


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