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* xfs: disable swap extents ioctl on CRC enabled filesystemsDave Chinner2013-05-301-0/+8
| | | | | | | | | | | | | | | | | | | | | | Currently, swapping extents from one inode to another is a simple act of switching data and attribute forks from one inode to another. This, unfortunately in no longer so simple with CRC enabled filesystems as there is owner information embedded into the BMBT blocks that are swapped between inodes. Hence swapping the forks between inodes results in the inodes having mapping blocks that point to the wrong owner and hence are considered corrupt. To fix this we need an extent tree block or record based swap algorithm so that the BMBT block owner information can be updated atomically in the swap transaction. This is a significant piece of new work, so for the moment simply don't allow swap extent operations to succeed on CRC enabled filesystems. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: fix split buffer vector log recovery supportDave Chinner2013-05-302-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A long time ago in a galaxy far away.... .. the was a commit made to fix some ilinux specific "fragmented buffer" log recovery problem: http://oss.sgi.com/cgi-bin/gitweb.cgi?p=archive/xfs-import.git;a=commitdiff;h=b29c0bece51da72fb3ff3b61391a391ea54e1603 That problem occurred when a contiguous dirty region of a buffer was split across across two pages of an unmapped buffer. It's been a long time since that has been done in XFS, and the changes to log the entire inode buffers for CRC enabled filesystems has re-introduced that corner case. And, of course, it turns out that the above commit didn't actually fix anything - it just ensured that log recovery is guaranteed to fail when this situation occurs. And now for the gory details. xfstest xfs/085 is failing with this assert: XFS (vdb): bad number of regions (0) in inode log format XFS: Assertion failed: 0, file: fs/xfs/xfs_log_recover.c, line: 1583 Largely undocumented factoid #1: Log recovery depends on all log buffer format items starting with this format: struct foo_log_format { __uint16_t type; __uint16_t size; .... As recoery uses the size field and assumptions about 32 bit alignment in decoding format items. So don't pay much attention to the fact log recovery thinks that it decoding an inode log format item - it just uses them to determine what the size of the item is. But why would it see a log format item with a zero size? Well, luckily enough xfs_logprint uses the same code and gives the same error, so with a bit of gdb magic, it turns out that it isn't a log format that is being decoded. What logprint tells us is this: Oper (130): tid: a0375e1a len: 28 clientid: TRANS flags: none BUF: #regs: 2 start blkno: 144 (0x90) len: 16 bmap size: 2 flags: 0x4000 Oper (131): tid: a0375e1a len: 4096 clientid: TRANS flags: none BUF DATA ---------------------------------------------------------------------------- Oper (132): tid: a0375e1a len: 4096 clientid: TRANS flags: none xfs_logprint: unknown log operation type (4e49) ********************************************************************** * ERROR: data block=2 * ********************************************************************** That we've got a buffer format item (oper 130) that has two regions; the format item itself and one dirty region. The subsequent region after the buffer format item and it's data is them what we are tripping over, and the first bytes of it at an inode magic number. Not a log opheader like there is supposed to be. That means there's a problem with the buffer format item. It's dirty data region is 4096 bytes, and it contains - you guessed it - initialised inodes. But inode buffers are 8k, not 4k, and we log them in their entirety. So something is wrong here. The buffer format item contains: (gdb) p /x *(struct xfs_buf_log_format *)in_f $22 = {blf_type = 0x123c, blf_size = 0x2, blf_flags = 0x4000, blf_len = 0x10, blf_blkno = 0x90, blf_map_size = 0x2, blf_data_map = {0xffffffff, 0xffffffff, .... }} Two regions, and a signle dirty contiguous region of 64 bits. 64 * 128 = 8k, so this should be followed by a single 8k region of data. And the blf_flags tell us that the type of buffer is a XFS_BLFT_DINO_BUF. It contains inodes. And because it doesn't have the XFS_BLF_INODE_BUF flag set, that means it's an inode allocation buffer. So, it should be followed by 8k of inode data. But we know that the next region has a header of: (gdb) p /x *ohead $25 = {oh_tid = 0x1a5e37a0, oh_len = 0x100000, oh_clientid = 0x69, oh_flags = 0x0, oh_res2 = 0x0} and so be32_to_cpu(oh_len) = 0x1000 = 4096 bytes. It's simply not long enough to hold all the logged data. There must be another region. There is - there's a following opheader for another 4k of data that contains the other half of the inode cluster data - the one we assert fail on because it's not a log format header. So why is the second part of the data not being accounted to the correct buffer log format structure? It took a little more work with gdb to work out that the buffer log format structure was both expecting it to be there but hadn't accounted for it. It was at that point I went to the kernel code, as clearly this wasn't a bug in xfs_logprint and the kernel was writing bad stuff to the log. First port of call was the buffer item formatting code, and the discontiguous memory/contiguous dirty region handling code immediately stood out. I've wondered for a long time why the code had this comment in it: vecp->i_addr = xfs_buf_offset(bp, buffer_offset); vecp->i_len = nbits * XFS_BLF_CHUNK; vecp->i_type = XLOG_REG_TYPE_BCHUNK; /* * You would think we need to bump the nvecs here too, but we do not * this number is used by recovery, and it gets confused by the boundary * split here * nvecs++; */ vecp++; And it didn't account for the extra vector pointer. The case being handled here is that a contiguous dirty region lies across a boundary that cannot be memcpy()d across, and so has to be split into two separate operations for xlog_write() to perform. What this code assumes is that what is written to the log is two consecutive blocks of data that are accounted in the buf log format item as the same contiguous dirty region and so will get decoded as such by the log recovery code. The thing is, xlog_write() knows nothing about this, and so just does it's normal thing of adding an opheader for each vector. That means the 8k region gets written to the log as two separate regions of 4k each, but because nvecs has not been incremented, the buf log format item accounts for only one of them. Hence when we come to log recovery, we process the first 4k region and then expect to come across a new item that starts with a log format structure of some kind that tells us whenteh next data is going to be. Instead, we hit raw buffer data and things go bad real quick. So, the commit from 2002 that commented out nvecs++ is just plain wrong. It breaks log recovery completely, and it would seem the only reason this hasn't been since then is that we don't log large contigous regions of multi-page unmapped buffers very often. Never would be a closer estimate, at least until the CRC code came along.... So, lets fix that by restoring the nvecs accounting for the extra region when we hit this case..... .... and there's the problemin log recovery it is apparently working around: XFS: Assertion failed: i == item->ri_total, file: fs/xfs/xfs_log_recover.c, line: 2135 Yup, xlog_recover_do_reg_buffer() doesn't handle contigous dirty regions being broken up into multiple regions by the log formatting code. That's an easy fix, though - if the number of contiguous dirty bits exceeds the length of the region being copied out of the log, only account for the number of dirty bits that region covers, and then loop again and copy more from the next region. It's a 2 line fix. Now xfstests xfs/085 passes, we have one less piece of mystery code, and one more important piece of knowledge about how to structure new log format items.. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: fix incorrect remote symlink block countDave Chinner2013-05-301-14/+6
| | | | | | | | | | | | | | | | | | | | When CRCs are enabled, the number of blocks needed to hold a remote symlink on a 1k block size filesystem may be 2 instead of 1. The transaction reservation for the allocated blocks was not taking this into account and only allocating one block. Hence when trying to read or invalidate such symlinks, we are mapping a hole where there should be a block and things go bad at that point. Fix the reservation to use the correct block count, clean up the block count calculation similar to the remote attribute calculation, and add a debug guard to detect when we don't write the entire symlink to disk. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: don't emit v5 superblock warnings on writeDave Chinner2013-05-301-7/+11
| | | | | | | | | | | | | | | | | | | | | | We write the superblock every 30s or so which results in the verifier being called. Right now that results in this output every 30s: XFS (vda): Version 5 superblock detected. This kernel has EXPERIMENTAL support enabled! Use of these features in this kernel is at your own risk! And spamming the logs. We don't need to check for whether we support v5 superblocks or whether there are feature bits we don't support set as these are only relevant when we first mount the filesytem. i.e. on superblock read. Hence for the write verification we can just skip all the checks (and hence verbose output) altogether. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: rework remote attr CRCsDave Chinner2013-05-234-158/+247
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* xfs: fully initialise temp leaf in xfs_attr3_leaf_compactDave Chinner2013-05-231-16/+26
| | | | | | | | | | | | | | | | | | | | | xfs_attr3_leaf_compact() uses a temporary buffer for compacting the the entries in a leaf. It copies the the original buffer into the temporary buffer, then zeros the original buffer completely. It then copies the entries back into the original buffer. However, the original buffer has not been correctly initialised, and so the movement of the entries goes horribly wrong. Make sure the zeroed destination buffer is fully initialised, and once we've set up the destination incore header appropriately, write is back to the buffer before starting to move entries around. While debugging this, the _d/_s prefixes weren't sufficient to remind me what buffer was what, so rename then all _src/_dst. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: fully initialise temp leaf in xfs_attr3_leaf_unbalanceDave Chinner2013-05-231-3/+13
| | | | | | | | | | | | | | | | | | xfs_attr3_leaf_unbalance() uses a temporary buffer for recombining the entries in two leaves when the destination leaf requires compaction. The temporary buffer ends up being copied back over the original destination buffer, so the header in the temporary buffer needs to contain all the information that is in the destination buffer. To make sure the temporary buffer is fully initialised, once we've set up the temporary incore header appropriately, write is back to the temporary buffer before starting to move entries around. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: correctly map remote attr buffers during removalDave Chinner2013-05-231-9/+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>
* xfs: remote attribute tail zeroing does too muchDave Chinner2013-05-231-19/+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>
* xfs: remote attribute read too shortDave Chinner2013-05-231-6/+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>
* xfs: remote attribute allocation may be contiguousDave Chinner2013-05-211-1/+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>
* xfs: avoid nesting transactions in xfs_qm_scall_setqlim()Dave Chinner2013-05-211-17/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lockdep reports: ============================================= [ INFO: possible recursive locking detected ] 3.9.0+ #3 Not tainted --------------------------------------------- setquota/28368 is trying to acquire lock: (sb_internal){++++.?}, at: [<c11e8846>] xfs_trans_alloc+0x26/0x50 but task is already holding lock: (sb_internal){++++.?}, at: [<c11e8846>] xfs_trans_alloc+0x26/0x50 from xfs_qm_scall_setqlim()->xfs_dqread() when a dquot needs to be allocated. xfs_qm_scall_setqlim() is starting a transaction and then not passing it into xfs_qm_dqet() and so it starts it's own transaction when allocating the dquot. Splat! Fix this by not allocating the dquot in xfs_qm_scall_setqlim() inside the setqlim transaction. This requires getting the dquot first (and allocating it if necessary) then dropping and relocking the dquot before joining it to the setqlim transaction. Reported-by: Michael L. Semon <mlsemon35@gmail.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: remote attribute lookups require the value lengthDave Chinner2013-05-201-1/+2
| | | | | | | | | | | | | | | When reading a remote attribute, to correctly calculate the length of the data buffer for CRC enable filesystems, we need to know the length of the attribute data. We get this information when we look up the attribute, but we don't store it in the args structure along with the other remote attr information we get from the lookup. Add this information to the args structure so we can use it appropriately. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: xfs_attr_shortform_allfit() does not handle attr3 format.Dave Chinner2013-05-201-11/+13
| | | | | | | | | | | | | xfstests generic/117 fails with: XFS: Assertion failed: leaf->hdr.info.magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) indicating a function that does not handle the attr3 format correctly. Fix it. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: xfs_da3_node_read_verify() doesn't handle XFS_ATTR3_LEAF_MAGICDave Chinner2013-05-201-0/+1
| | | | | | | 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 missing KM_NOFS tags to keep lockdep happyDave Chinner2013-05-204-5/+7
| | | | | | | | | | | | | | | There are several places where we use KM_SLEEP allocation contexts and use the fact that they are called from transaction context to add KM_NOFS where appropriate. Unfortunately, there are several places where the code makes this assumption but can be called from outside transaction context but with filesystem locks held. These places need explicit KM_NOFS annotations to avoid lockdep complaining about reclaim contexts. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: Don't reference the EFI after it is freedDave Chinner2013-05-201-2/+3
| | | | | | | | | | | | | Checking the EFI for whether it is being released from recovery after we've already released the known active reference is a mistake worthy of a brown paper bag. Fix the (now) obvious use after free that it can cause. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: fix rounding in xfs_free_file_spaceDave Chinner2013-05-201-2/+2
| | | | | | | | | | | | | | | | | | The offset passed into xfs_free_file_space() needs to be rounded down to a certain size, but the rounding mask is built by a 32 bit variable. Hence the mask will always mask off the upper 32 bits of the offset and lead to incorrect writeback and invalidation ranges. This is not actually exposed as a bug because we writeback and invalidate from the rounded offset to the end of the file, and hence the offset we are actually punching a hole out of will always be covered by the code. This needs fixing, however, if we ever want to use exact ranges for writeback/invalidation here... Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: fix sub-page blocksize data integrity writesDave Chinner2013-05-201-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | FSX on 512 byte block size filesystems has been failing for some time with corrupted data. The fault dates back to the change in the writeback data integrity algorithm that uses a mark-and-sweep approach to avoid data writeback livelocks. Unfortunately, a side effect of this mark-and-sweep approach is that each page will only be written once for a data integrity sync, and there is a condition in writeback in XFS where a page may require two writeback attempts to be fully written. As a result of the high level change, we now only get a partial page writeback during the integrity sync because the first pass through writeback clears the mark left on the page index to tell writeback that the page needs writeback.... The cause is writing a partial page in the clustering code. This can happen when a mapping boundary falls in the middle of a page - we end up writing back the first part of the page that the mapping covers, but then never revisit the page to have the remainder mapped and written. The fix is simple - if the mapping boundary falls inside a page, then simple abort clustering without touching the page. This means that the next ->writepage entry that write_cache_pages() will make is the page we aborted on, and xfs_vm_writepage() will map all sections of the page correctly. This behaviour is also optimal for non-data integrity writes, as it results in contiguous sequential writeback of the file rather than missing small holes and having to write them a "random" writes in a future pass. With this fix, all the fsx tests in xfstests now pass on a 512 byte block size filesystem on a 4k page machine. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: Avoid pathological backwards allocationJan Kara2013-05-201-6/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Writing a large file using direct IO in 16 MB chunks sometimes results in a pathological allocation pattern where 16 MB chunks of large free extent are allocated to a file in a reversed order. So extents of a file look for example as: ext logical physical expected length flags 0 0 13 4550656 1 4550656 188136807 4550668 12562432 2 17113088 200699240 200699238 622592 3 17735680 182046055 201321831 4096 4 17739776 182041959 182050150 4096 5 17743872 182037863 182046054 4096 6 17747968 182033767 182041958 4096 7 17752064 182029671 182037862 4096 ... 6757 45400064 154381644 154389835 4096 6758 45404160 154377548 154385739 4096 6759 45408256 252951571 154381643 73728 eof This happens because XFS_ALLOCTYPE_THIS_BNO allocation fails (the last extent in the file cannot be further extended) so we fall back to XFS_ALLOCTYPE_NEAR_BNO allocation which picks end of a large free extent as the best place to continue the file. Since the chunk at the end of the free extent again cannot be further extended, this behavior repeats until the whole free extent is consumed in a reversed order. For data allocations this backward allocation isn't beneficial so make xfs_alloc_compute_diff() pick start of a free extent instead of its end for them. That avoids the backward allocation pattern. See thread at http://oss.sgi.com/archives/xfs/2013-03/msg00144.html for more details about the reproduction case and why this solution was chosen. Based on idea by Dave Chinner <dchinner@redhat.com>. CC: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* Linux 3.10-rc1v3.10-rc1Linus Torvalds2013-05-111-2/+2
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* Merge tag 'trace-fixes-v3.10' of ↵Linus Torvalds2013-05-116-108/+368
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing/kprobes update from Steven Rostedt: "The majority of these changes are from Masami Hiramatsu bringing kprobes up to par with the latest changes to ftrace (multi buffering and the new function probes). He also discovered and fixed some bugs in doing so. When pulling in his patches, I also found a few minor bugs as well and fixed them. This also includes a compile fix for some archs that select the ring buffer but not tracing. I based this off of the last patch you took from me that fixed the merge conflict error, as that was the commit that had all the changes I needed for this set of changes." * tag 'trace-fixes-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing/kprobes: Support soft-mode disabling tracing/kprobes: Support ftrace_event_file base multibuffer tracing/kprobes: Pass trace_probe directly from dispatcher tracing/kprobes: Increment probe hit-count even if it is used by perf tracing/kprobes: Use bool for retprobe checker ftrace: Fix function probe when more than one probe is added ftrace: Fix the output of enabled_functions debug file ftrace: Fix locking in register_ftrace_function_probe() tracing: Add helper function trace_create_new_event() to remove duplicate code tracing: Modify soft-mode only if there's no other referrer tracing: Indicate enabled soft-mode in enable file tracing/kprobes: Fix to increment return event probe hit-count ftrace: Cleanup regex_lock and ftrace_lock around hash updating ftrace, kprobes: Fix a deadlock on ftrace_regex_lock ftrace: Have ftrace_regex_write() return either read or error tracing: Return error if register_ftrace_function_probe() fails for event_enable_func() tracing: Don't succeed if event_enable_func did not register anything ring-buffer: Select IRQ_WORK
| * tracing/kprobes: Support soft-mode disablingMasami Hiramatsu2013-05-091-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Support soft-mode disabling on kprobe-based dynamic events. Soft-disabling is just ignoring recording if the soft disabled flag is set. Link: http://lkml.kernel.org/r/20130509054454.30398.7237.stgit@mhiramat-M0-7522 Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing/kprobes: Support ftrace_event_file base multibufferMasami Hiramatsu2013-05-091-36/+214
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Support multi-buffer on kprobe-based dynamic events by using ftrace_event_file. Link: http://lkml.kernel.org/r/20130509054449.30398.88343.stgit@mhiramat-M0-7522 Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing/kprobes: Pass trace_probe directly from dispatcherMasami Hiramatsu2013-05-091-17/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pass the pointer of struct trace_probe directly from probe dispatcher to handlers. This removes redundant container_of macro uses. Same thing has already done in trace_uprobe. Link: http://lkml.kernel.org/r/20130509054441.30398.69112.stgit@mhiramat-M0-7522 Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing/kprobes: Increment probe hit-count even if it is used by perfMasami Hiramatsu2013-05-091-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Increment probe hit-count for profiling even if it is used by perf tool. Same thing has already done in trace_uprobe. Link: http://lkml.kernel.org/r/20130509054436.30398.21133.stgit@mhiramat-M0-7522 Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing/kprobes: Use bool for retprobe checkerMasami Hiramatsu2013-05-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Use bool instead of int for kretprobe checker. Link: http://lkml.kernel.org/r/20130509054431.30398.38561.stgit@mhiramat-M0-7522 Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Fix function probe when more than one probe is addedSteven Rostedt (Red Hat)2013-05-091-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the first function probe is added and the function tracer is updated the functions are modified to call the probe. But when a second function is added, it updates the function records to have the second function also update, but it fails to update the actual function itself. This prevents the second (or third or forth and so on) probes from having their functions called. # echo vfs_symlink:enable_event:sched:sched_switch > set_ftrace_filter # echo vfs_unlink:enable_event:sched:sched_switch > set_ftrace_filter # cat trace # tracer: nop # # entries-in-buffer/entries-written: 0/0 #P:4 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | # touch /tmp/a # rm /tmp/a # cat trace # tracer: nop # # entries-in-buffer/entries-written: 0/0 #P:4 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | # ln -s /tmp/a # cat trace # tracer: nop # # entries-in-buffer/entries-written: 414/414 #P:4 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | <idle>-0 [000] d..3 2847.923031: sched_switch: prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=2786 next_prio=120 <...>-3114 [001] d..4 2847.923035: sched_switch: prev_comm=ln prev_pid=3114 prev_prio=120 prev_state=x ==> next_comm=swapper/1 next_pid=0 next_prio=120 bash-2786 [000] d..3 2847.923535: sched_switch: prev_comm=bash prev_pid=2786 prev_prio=120 prev_state=S ==> next_comm=kworker/0:1 next_pid=34 next_prio=120 kworker/0:1-34 [000] d..3 2847.923552: sched_switch: prev_comm=kworker/0:1 prev_pid=34 prev_prio=120 prev_state=S ==> next_comm=swapper/0 next_pid=0 next_prio=120 <idle>-0 [002] d..3 2847.923554: sched_switch: prev_comm=swapper/2 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=sshd next_pid=2783 next_prio=120 sshd-2783 [002] d..3 2847.923660: sched_switch: prev_comm=sshd prev_pid=2783 prev_prio=120 prev_state=S ==> next_comm=swapper/2 next_pid=0 next_prio=120 Still need to update the functions even though the probe itself does not need to be registered again when added a new probe. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Fix the output of enabled_functions debug fileSteven Rostedt (Red Hat)2013-05-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The enabled_functions debugfs file was created to be able to see what functions have been modified from nops to calling a tracer. The current method uses the counter in the function record. As when a ftrace_ops is registered to a function, its count increases. But that doesn't mean that the function is actively being traced. /proc/sys/kernel/ftrace_enabled can be set to zero which would disable it, as well as something can go wrong and we can think its enabled when only the counter is set. The record's FTRACE_FL_ENABLED flag is set or cleared when its function is modified. That is a much more accurate way of knowing what function is enabled or not. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Fix locking in register_ftrace_function_probe()Steven Rostedt (Red Hat)2013-05-091-4/+6
| | | | | | | | | | | | | | The iteration of the ftrace function list and the call to ftrace_match_record() need to be protected by the ftrace_lock. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add helper function trace_create_new_event() to remove duplicate codeSteven Rostedt (Red Hat)2013-05-091-12/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Both __trace_add_new_event() and __trace_early_add_new_event() do basically the same thing, except that __trace_add_new_event() does a little more. Instead of having duplicate code between the two functions, add a helper function trace_create_new_event() that both can use. This will help against having bugs fixed in one function but not the other. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Modify soft-mode only if there's no other referrerMasami Hiramatsu2013-05-092-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modify soft-mode flag only if no other soft-mode referrer (currently only the ftrace triggers) by using a reference counter in each ftrace_event_file. Without this fix, adding and removing several different enable/disable_event triggers on the same event clear soft-mode bit from the ftrace_event_file. This also happens with a typo of glob on setting triggers. e.g. # echo vfs_symlink:enable_event:net:netif_rx > set_ftrace_filter # cat events/net/netif_rx/enable 0* # echo typo_func:enable_event:net:netif_rx > set_ftrace_filter # cat events/net/netif_rx/enable 0 # cat set_ftrace_filter #### all functions enabled #### vfs_symlink:enable_event:net:netif_rx:unlimited As above, we still have a trigger, but soft-mode is gone. Link: http://lkml.kernel.org/r/20130509054429.30398.7464.stgit@mhiramat-M0-7522 Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: David Sharp <dhsharp@google.com> Cc: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Indicate enabled soft-mode in enable fileMasami Hiramatsu2013-05-091-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Indicate enabled soft-mode event as "1*" in "enable" file for each event, because it can be soft-disabled when disable_event trigger is hit. Link: http://lkml.kernel.org/r/20130509054426.30398.28202.stgit@mhiramat-M0-7522 Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing/kprobes: Fix to increment return event probe hit-countMasami Hiramatsu2013-05-091-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix to increment probe hit-count for function return event. Link: http://lkml.kernel.org/r/20130509054424.30398.34058.stgit@mhiramat-M0-7522 Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Cleanup regex_lock and ftrace_lock around hash updatingMasami Hiramatsu2013-05-091-27/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cleanup regex_lock and ftrace_lock locking points around ftrace_ops hash update code. The new rule is that regex_lock protects ops->*_hash read-update-write code for each ftrace_ops. Usually, hash update is done by following sequence. 1. allocate a new local hash and copy the original hash. 2. update the local hash. 3. move(actually, copy) back the local hash to ftrace_ops. 4. update ftrace entries if needed. 5. release the local hash. This makes regex_lock protect #1-#4, and ftrace_lock to protect #3, #4 and adding and removing ftrace_ops from the ftrace_ops_list. The ftrace_lock protects #3 as well because the move functions update the entries too. Link: http://lkml.kernel.org/r/20130509054421.30398.83411.stgit@mhiramat-M0-7522 Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace, kprobes: Fix a deadlock on ftrace_regex_lockMasami Hiramatsu2013-05-092-21/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a deadlock on ftrace_regex_lock which happens when setting an enable_event trigger on dynamic kprobe event as below. ---- sh-2.05b# echo p vfs_symlink > kprobe_events sh-2.05b# echo vfs_symlink:enable_event:kprobes:p_vfs_symlink_0 > set_ftrace_filter ============================================= [ INFO: possible recursive locking detected ] 3.9.0+ #35 Not tainted --------------------------------------------- sh/72 is trying to acquire lock: (ftrace_regex_lock){+.+.+.}, at: [<ffffffff810ba6c1>] ftrace_set_hash+0x81/0x1f0 but task is already holding lock: (ftrace_regex_lock){+.+.+.}, at: [<ffffffff810b7cbd>] ftrace_regex_write.isra.29.part.30+0x3d/0x220 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(ftrace_regex_lock); lock(ftrace_regex_lock); *** DEADLOCK *** ---- To fix that, this introduces a finer regex_lock for each ftrace_ops. ftrace_regex_lock is too big of a lock which protects all filter/notrace_hash operations, but it doesn't need to be a global lock after supporting multiple ftrace_ops because each ftrace_ops has its own filter/notrace_hash. Link: http://lkml.kernel.org/r/20130509054417.30398.84254.stgit@mhiramat-M0-7522 Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> [ Added initialization flag and automate mutex initialization for non ftrace.c ftrace_probes. ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Have ftrace_regex_write() return either read or errorSteven Rostedt (Red Hat)2013-05-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | As ftrace_regex_write() reads the result of ftrace_process_regex() which can sometimes return a positive number, only consider a failure if the return is negative. Otherwise, it will skip possible other registered probes and by returning a positive number that wasn't read, it will confuse the user processes doing the writing. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Return error if register_ftrace_function_probe() fails for ↵Steven Rostedt (Red Hat)2013-05-091-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | event_enable_func() register_ftrace_function_probe() returns the number of functions it registered, which can be zero, it can also return a negative number if something went wrong. But event_enable_func() only checks for the case that it didn't register anything, it needs to also check for the case that something went wrong and return that error code as well. Added some comments about the code as well, to make it more understandable. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Don't succeed if event_enable_func did not register anythingMasami Hiramatsu2013-05-091-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Return 0 instead of the number of activated ftrace function probes if event_enable_func succeeded and return an error code if it failed or did not register any functions. But it currently returns the number of registered functions and if it didn't register anything, it returns 0, but that is considered success. This also fixes the return value. As if it succeeds, it returns the number of functions that were enabled, which is returned back to the user in ftrace_regex_write (the write() return code). If only one function is enabled, then the return code of the write is one, and this can confuse the user program in thinking it only wrote 1 byte. Link: http://lkml.kernel.org/r/20130509054413.30398.55650.stgit@mhiramat-M0-7522 Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> [ Rewrote change log to reflect that this fixes two bugs - SR ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Select IRQ_WORKSteven Rostedt (Red Hat)2013-05-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As the wake up logic for waiters on the buffer has been moved from the tracing code to the ring buffer, it requires also adding IRQ_WORK as the wake up code is performed via irq_work. This fixes compile breakage when a user of the ring buffer is selected but tracing and irq_work are not. Link http://lkml.kernel.org/r/20130503115332.GT8356@rric.localhost Cc: Arnd Bergmann <arnd@arndb.de> Reported-by: Robert Richter <rric@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge tag 'stable/for-linus-3.10-rc0-tag-two' of ↵Linus Torvalds2013-05-115-7/+55
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen Pull Xen bug-fixes from Konrad Rzeszutek Wilk: - More fixes in the vCPU PVHVM hotplug path. - Add more documentation. - Fix various ARM related issues in the Xen generic drivers. - Updates in the xen-pciback driver per Bjorn's updates. - Mask the x2APIC feature for PV guests. * tag 'stable/for-linus-3.10-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/pci: Used cached MSI-X capability offset xen/pci: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASK xen: clear IRQ_NOAUTOEN and IRQ_NOREQUEST xen: mask x2APIC feature in PV xen: SWIOTLB is only used on x86 xen/spinlock: Fix check from greater than to be also be greater or equal to. xen/smp/pvhvm: Don't point per_cpu(xen_vpcu, 33 and larger) to shared_info xen/vcpu: Document the xen_vcpu_info and xen_vcpu xen/vcpu/pvhvm: Fix vcpu hotplugging hanging.
| * | xen/pci: Used cached MSI-X capability offsetBjorn Helgaas2013-05-101-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We now cache the MSI-X capability offset in the struct pci_dev, so no need to find the capability again. Acked-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | xen/pci: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASKBjorn Helgaas2013-05-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PCI_MSIX_FLAGS_BIRMASK is mis-named because the BIR mask is in the Table Offset register, not the flags ("Message Control" per spec) register. Acked-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | xen: clear IRQ_NOAUTOEN and IRQ_NOREQUESTJulien Grall2013-05-081-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn't call irq_startup, that is responsible for calling irq_unmask at startup time. As a result event channels remain masked. The clear is already made in bind_evtchn_to_irq with commit a8636c0 but was missing on all others bind_*_to_irq. Move the clear in xen_irq_info_common_init. On x86, IRQ_NOAUTOEN and IRQ_NOREQUEST are cleared by default, so this commit doesn't impact this architecture. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Julien Grall <julien.grall@linaro.org> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | xen: mask x2APIC feature in PVZhenzhong Duan2013-05-081-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On x2apic enabled pvm, doing sysrq+l, got NULL pointer dereference as below. SysRq : Show backtrace of all active CPUs BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8125e3cb>] memcpy+0xb/0x120 Call Trace: [<ffffffff81039633>] ? __x2apic_send_IPI_mask+0x73/0x160 [<ffffffff8103973e>] x2apic_send_IPI_all+0x1e/0x20 [<ffffffff8103498c>] arch_trigger_all_cpu_backtrace+0x6c/0xb0 [<ffffffff81501be4>] ? _raw_spin_lock_irqsave+0x34/0x50 [<ffffffff8131654e>] sysrq_handle_showallcpus+0xe/0x10 [<ffffffff8131616d>] __handle_sysrq+0x7d/0x140 [<ffffffff81316230>] ? __handle_sysrq+0x140/0x140 [<ffffffff81316287>] write_sysrq_trigger+0x57/0x60 [<ffffffff811ca996>] proc_reg_write+0x86/0xc0 [<ffffffff8116dd8e>] vfs_write+0xce/0x190 [<ffffffff8116e3e5>] sys_write+0x55/0x90 [<ffffffff8150a242>] system_call_fastpath+0x16/0x1b That's because apic points to apic_x2apic_cluster or apic_x2apic_phys but the basic element like cpumask isn't initialized. Mask x2APIC feature in pvm to avoid overwrite of apic pointer, update commit message per Konrad's suggestion. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Tested-by: Tamon Shiose <tamon.shiose@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | xen: SWIOTLB is only used on x86Arnd Bergmann2013-05-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enabling SWIOTLB_XEN on ARM results in build errors because the underlying SWIOTLB is only available on X86: drivers/xen/swiotlb-xen.c: In function 'is_xen_swiotlb_buffer': drivers/xen/swiotlb-xen.c:105:2: error: implicit declaration of function 'mfn_to_local_pfn Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | xen/spinlock: Fix check from greater than to be also be greater or equal to.Konrad Rzeszutek Wilk2013-05-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During review of git commit cb9c6f15f318aa3aeb62fe525aa5c6dcf6eee159 ("xen/spinlock: Check against default value of -1 for IRQ line.") Stefano pointed out a bug in the patch. Unfortunatly due to vacation timing the fix was not applied and this patch fixes it up. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | xen/smp/pvhvm: Don't point per_cpu(xen_vpcu, 33 and larger) to shared_infoKonrad Rzeszutek Wilk2013-05-081-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As it will point to some data, but not event channel data (the shared_info has an array limited to 32). This means that for PVHVM guests with more than 32 VCPUs without the usage of VCPUOP_register_info any interrupts to VCPUs larger than 32 would have gone unnoticed during early bootup. That is OK, as during early bootup, in smp_init we end up calling the hotplug mechanism (xen_hvm_cpu_notify) which makes the VCPUOP_register_vcpu_info call for all VCPUs and we can receive interrupts on VCPUs 33 and further. This is just a cleanup. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | xen/vcpu: Document the xen_vcpu_info and xen_vcpuKonrad Rzeszutek Wilk2013-05-071-1/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | They are important structures and it is not clear at first look what they are for. The xen_vcpu is a pointer. By default it points to the shared_info structure (at the CPU offset location). However if the VCPUOP_register_vcpu_info hypercall is implemented we can make the xen_vcpu pointer point to a per-CPU location. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> [v1: Added comments from Ian Campbell] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | xen/vcpu/pvhvm: Fix vcpu hotplugging hanging.Konrad Rzeszutek Wilk2013-05-061-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a user did: echo 0 > /sys/devices/system/cpu/cpu1/online echo 1 > /sys/devices/system/cpu/cpu1/online we would (this a build with DEBUG enabled) get to: smpboot: ++++++++++++++++++++=_---CPU UP 1 .. snip.. smpboot: Stack at about ffff880074c0ff44 smpboot: CPU1: has booted. and hang. The RCU mechanism would kick in an try to IPI the CPU1 but the IPIs (and all other interrupts) would never arrive at the CPU1. At first glance at least. A bit digging in the hypervisor trace shows that (using xenanalyze): [vla] d4v1 vec 243 injecting 0.043163027 --|x d4v1 intr_window vec 243 src 5(vector) intr f3 ] 0.043163639 --|x d4v1 vmentry cycles 1468 ] 0.043164913 --|x d4v1 vmexit exit_reason PENDING_INTERRUPT eip ffffffff81673254 0.043164913 --|x d4v1 inj_virq vec 243 real [vla] d4v1 vec 243 injecting 0.043164913 --|x d4v1 intr_window vec 243 src 5(vector) intr f3 ] 0.043165526 --|x d4v1 vmentry cycles 1472 ] 0.043166800 --|x d4v1 vmexit exit_reason PENDING_INTERRUPT eip ffffffff81673254 0.043166800 --|x d4v1 inj_virq vec 243 real [vla] d4v1 vec 243 injecting there is a pending event (subsequent debugging shows it is the IPI from the VCPU0 when smpboot.c on VCPU1 has done "set_cpu_online(smp_processor_id(), true)") and the guest VCPU1 is interrupted with the callback IPI (0xf3 aka 243) which ends up calling __xen_evtchn_do_upcall. The __xen_evtchn_do_upcall seems to do *something* but not acknowledge the pending events. And the moment the guest does a 'cli' (that is the ffffffff81673254 in the log above) the hypervisor is invoked again to inject the IPI (0xf3) to tell the guest it has pending interrupts. This repeats itself forever. The culprit was the per_cpu(xen_vcpu, cpu) pointer. At the bootup we set each per_cpu(xen_vcpu, cpu) to point to the shared_info->vcpu_info[vcpu] but later on use the VCPUOP_register_vcpu_info to register per-CPU structures (xen_vcpu_setup). This is used to allow events for more than 32 VCPUs and for performance optimizations reasons. When the user performs the VCPU hotplug we end up calling the the xen_vcpu_setup once more. We make the hypercall which returns -EINVAL as it does not allow multiple registration calls (and already has re-assigned where the events are being set). We pick the fallback case and set per_cpu(xen_vcpu, cpu) to point to the shared_info->vcpu_info[vcpu] (which is a good fallback during bootup). However the hypervisor is still setting events in the register per-cpu structure (per_cpu(xen_vcpu_info, cpu)). As such when the events are set by the hypervisor (such as timer one), and when we iterate in __xen_evtchn_do_upcall we end up reading stale events from the shared_info->vcpu_info[vcpu] instead of the per_cpu(xen_vcpu_info, cpu) structures. Hence we never acknowledge the events that the hypervisor has set and the hypervisor keeps on reminding us to ack the events which we never do. The fix is simple. Don't on the second time when xen_vcpu_setup is called over-write the per_cpu(xen_vcpu, cpu) if it points to per_cpu(xen_vcpu_info). Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> CC: stable@vger.kernel.org Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>