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* xfs: fix static and extern sparse warningsDave Chinner2013-10-301-0/+1
| | | | | | | | | | | | The kbuild test robot indicated that there were some new sparse warnings in fs/xfs/xfs_dquot_buf.c. Actually, there were a lot more that is wasn't warning about, so fix them all up. Reported-by: kbuild test robot Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: decouple inode and bmap btree header filesDave Chinner2013-10-231-3/+2
| | | | | | | | | | | | | | | | | | | | Currently the xfs_inode.h header has a dependency on the definition of the BMAP btree records as the inode fork includes an array of xfs_bmbt_rec_host_t objects in it's definition. Move all the btree format definitions from xfs_btree.h, xfs_bmap_btree.h, xfs_alloc_btree.h and xfs_ialloc_btree.h to xfs_format.h to continue the process of centralising the on-disk format definitions. With this done, the xfs inode definitions are no longer dependent on btree header files. The enables a massive culling of unnecessary includes, with close to 200 #include directives removed from the XFS kernel code base. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: decouple log and transaction headersDave Chinner2013-10-231-4/+3
| | | | | | | | | | | | | | | | | | | | | xfs_trans.h has a dependency on xfs_log.h for a couple of structures. Most code that does transactions doesn't need to know anything about the log, but this dependency means that they have to include xfs_log.h. Decouple the xfs_trans.h and xfs_log.h header files and clean up the includes to be in dependency order. In doing this, remove the direct include of xfs_trans_reserve.h from xfs_trans.h so that we remove the dependency between xfs_trans.h and xfs_mount.h. Hence the xfs_trans.h include can be moved to the indicate the actual dependencies other header files have on it. Note that these are kernel only header files, so this does not translate to any userspace changes at all. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: unify directory/attribute format definitionsDave Chinner2013-10-231-0/+1
| | | | | | | | | | | | | | 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>
* xfs: fix issues that cause userspace warningsDave Chinner2013-08-121-4/+4
| | | | | | | | | | | Some of the code shared with userspace causes compilation warnings from things turned off in the kernel code, such as differences in variable signedness. Fix those issues. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: minor cleanupsDave Chinner2013-08-121-7/+1
| | | | | | | | | | These come from syncing the shared userspace and kernel code. Small whitespace and trivial cleanups. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: create xfs_bmap_util.[ch]Dave Chinner2013-08-121-0/+1
| | | | | | | | | | | | | | | | | | | | | | | There is a bunch of code in xfs_bmap.c that is kernel specific and not shared with userspace. To minimise the difference between the kernel and userspace code, shift this unshared code to xfs_bmap_util.c, and the declarations to xfs_bmap_util.h. The biggest issue here is xfs_bmap_finish() - userspace has it's own definition of this function, and so we need to move it out of xfs_bmap.[ch]. This means several other files need to include xfs_bmap_util.h as well. It also introduces and interesting dance for the stack switching code in xfs_bmapi_allocate(). The stack switching/workqueue code is actually moved to xfs_bmap_util.c, so that userspace can simply use a #define in a header file to connect the dots without needing to know about the stack switch code at all. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: sync minor header differences needed by userspace.Dave Chinner2013-08-121-0/+1
| | | | | | | | | | | Little things like exported functions, __KERNEL__ protections, and so on that ensure user and kernel shared headers are identical. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: rework remote attr CRCsDave Chinner2013-05-301-153/+228
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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)
* xfs: correctly map remote attr buffers during removalDave Chinner2013-05-301-9/+18
| | | | | | | | | | | | | | | If we don't map the buffers correctly (same as for get/set operations) then the incore buffer lookup will fail. If a block number matches but a length is wrong, then debug kernels will ASSERT fail in _xfs_buf_find() due to the length mismatch. Ensure that we map the buffers correctly by basing the length of the buffer on the attribute data length rather than the remote block count. 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 6863ef8449f1908c19f43db572e4474f24a1e9da)
* xfs: remote attribute tail zeroing does too muchDave Chinner2013-05-301-19/+18
| | | | | | | | | | | | | | | | | | | | | | | | When an attribute data does not fill then entire remote block, we zero the remaining part of the buffer. This, however, needs to take into account that the buffer has a header, and so the offset where zeroing starts and the length of zeroing need to take this into account. Otherwise we end up with zeros over the end of the attribute value when CRCs are enabled. While there, make sure we only ask to map an extent that covers the remaining range of the attribute, rather than asking every time for the full length of remote data. If the remote attribute blocks are contiguous with other parts of the attribute tree, it will map those blocks as well and we can potentially zero them incorrectly. We can also get buffer size mistmatches when trying to read or remove the remote attribute, and this can lead to not finding the correct buffer when looking it up in cache. 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 4af3644c9a53eb2f1ecf69cc53576561b64be4c6)
* xfs: remote attribute read too shortDave Chinner2013-05-301-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | Reading a maximally size remote attribute fails when CRCs are enabled with this verification error: XFS (vdb): remote attribute header does not match required off/len/owner) There are two reasons for this, the first being that the length of the buffer being read is determined from the args->rmtblkcnt which doesn't take into account CRC headers. Hence the mapped length ends up being too short and so we need to calculate it directly from the value length. The second is that the byte count of valid data within a buffer is capped by the length of the data and so doesn't take into account that the buffer might be longer due to headers. Hence we need to calculate the data space in the buffer first before calculating the actual byte count of data. 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 913e96bc292e1bb248854686c79d6545ef3ee720)
* xfs: remote attribute allocation may be contiguousDave Chinner2013-05-301-1/+5
| | | | | | | | | | | | | | | | | When CRCs are enabled, there may be multiple allocations made if the headers cause a length overflow. This, however, does not mean that the number of headers required increases, as the second and subsequent extents may be contiguous with the previous extent. Hence when we map the extents to write the attribute data, we may end up with less extents than allocations made. Hence the assertion that we consume the number of headers we calculated in the allocation loop is incorrect and needs to be removed. 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 90253cf142469a40f89f989904abf0a1e500e1a6)
* xfs: Remote attr validation fixes and optimisationsDave Chinner2013-05-011-14/+5
| | | | | | | | | | | | - optimise the calcuation for the number of blocks in a remote xattr. - check attribute length against MAX_XATTR_SIZE, not MAXPATHLEN - whitespace fixes Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: add CRC protection to remote attributesDave Chinner2013-04-271-51/+273
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* xfs: split remote attribute code outDave Chinner2013-04-271-0/+328
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>