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2016-05-30Btrfs: fix race between device replace and chunk allocationFilipe Manana
While iterating and copying extents from the source device, the device replace code keeps adjusting a left cursor that is used to make sure that once we finish processing a device extent, any future writes to extents from the corresponding block group will get into both the source and target devices. This left cursor is also used for resuming the device replace operation at mount time. However using this left cursor to decide whether writes go into both devices or only the source device is not enough to guarantee we don't miss copying extents into the target device. There are two cases where the current approach fails. The first one is related to when there are holes in the device and they get allocated for new block groups while the device replace operation is iterating the device extents (more on this explained below). The second one is that when that loop over the device extents finishes, we start dellaloc, wait for all ordered extents and then commit the current transaction, we might have got new block groups allocated that are now using a device extent that has an offset greater then or equals to the value of the left cursor, in which case writes to extents belonging to these new block groups will get issued only to the source device. For the first case where the current approach of using a left cursor fails, consider the source device currently has the following layout: [ extent bg A ] [ hole, unallocated space ] [extent bg B ] 3Gb 4Gb 5Gb While we are iterating the device extents from the source device using the commit root of the device tree, the following happens: CPU 1 CPU 2 <we are at transaction N> scrub_enumerate_chunks() --> searches the device tree for extents belonging to the source device using the device tree's commit root --> 1st iteration finds extent belonging to block group A --> sets block group A to RO mode (btrfs_inc_block_group_ro) --> sets cursor left to found_key.offset which is 3Gb --> scrub_chunk() starts copies all allocated extents from block group's A stripe at source device into target device btrfs_alloc_chunk() --> allocates device extent in the range [4Gb, 5Gb[ from the source device for a new block group C extent allocated from block group C for a direct IO, buffered write or btree node/leaf extent is written to, perhaps in response to a writepages() call from the VM or directly through direct IO the write is made only against the source device and not against the target device because the extent's offset is in the interval [4Gb, 5Gb[ which is larger then the value of cursor_left (3Gb) --> scrub_chunks() finishes --> updates left cursor from 3Gb to 4Gb --> btrfs_dec_block_group_ro() sets block group A back to RW mode <we are still at transaction N> --> 2nd iteration finds extent belonging to block group B - it did not find the new extent in the range [4Gb, 5Gb[ for block group C because we are using the device tree's commit root or even because the block group's items are not all yet inserted in the respective btrees, that is, the block group is still attached to some transaction handle's new_bgs list and btrfs_create_pending_block_groups() was not called yet against that transaction handle, so the device extent items were not yet inserted into the devices tree <we are still at transaction N> --> so we end not copying anything from the newly allocated device extent from the source device to the target device So fix this by making __btrfs_map_block() always redirect writes to the target device as well, independently of the left cursor's value. With this change the left cursor is now used only for the purpose of tracking progress and allow a mount operation to resume a device replace. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30Btrfs: fix race setting block group back to RW mode during device replaceFilipe Manana
After it finishes processing a device extent, the device replace code sets back the block group to RW mode and then after that it sets the left cursor to match the logical end address of the block group, so that future writes into extents belonging to the block group go both the source (old) and target (new) devices. However from the moment we turn the block group back to RW mode we have a short time window, that lasts until we update the left cursor's value, where extents can be allocated from the block group and written to, in which case they will not be copied/written to the target (new) device. Fix this by updating the left cursor's value before turning the block group back to RW mode. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30Btrfs: fix unprotected assignment of the left cursor for device replaceFilipe Manana
We were assigning new values to fields of the device replace object without holding the respective lock after processing each device extent. This is important for the left cursor field which can be accessed by a concurrent task running __btrfs_map_block (which, correctly, takes the device replace lock). So change these fields while holding the device replace lock. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30Btrfs: fix race setting block group readonly during device replaceFilipe Manana
When we do a device replace, for each device extent we find from the source device, we set the corresponding block group to readonly mode to prevent writes into it from happening while we are copying the device extent from the source to the target device. However just before we set the block group to readonly mode some concurrent task might have already allocated an extent from it or decided it could perform a nocow write into one of its extents, which can make the device replace process to miss copying an extent since it uses the extent tree's commit root to search for extents and only once it finishes searching for all extents belonging to the block group it does set the left cursor to the logical end address of the block group - this is a problem if the respective ordered extents finish while we are searching for extents using the extent tree's commit root and no transaction commit happens while we are iterating the tree, since it's the delayed references created by the ordered extents (when they complete) that insert the extent items into the extent tree (using the non-commit root of course). Example: CPU 1 CPU 2 btrfs_dev_replace_start() btrfs_scrub_dev() scrub_enumerate_chunks() --> finds device extent belonging to block group X <transaction N starts> starts buffered write against some inode writepages is run against that inode forcing dellaloc to run btrfs_writepages() extent_writepages() extent_write_cache_pages() __extent_writepage() writepage_delalloc() run_delalloc_range() cow_file_range() btrfs_reserve_extent() --> allocates an extent from block group X (which is not yet in RO mode) btrfs_add_ordered_extent() --> creates ordered extent Y flush_epd_write_bio() --> bio against the extent from block group X is submitted btrfs_inc_block_group_ro(bg X) --> sets block group X to readonly scrub_chunk(bg X) scrub_stripe(device extent from srcdev) --> keeps searching for extent items belonging to the block group using the extent tree's commit root --> it never blocks due to fs_info->scrub_pause_req as no one tries to commit transaction N --> copies all extents found from the source device into the target device --> finishes search loop bio completes ordered extent Y completes and creates delayed data reference which will add an extent item to the extent tree when run (typically at transaction commit time) --> so the task doing the scrub/device replace at CPU 1 misses this and does not copy this extent into the new/target device btrfs_dec_block_group_ro(bg X) --> turns block group X back to RW mode dev_replace->cursor_left is set to the logical end offset of block group X So fix this by waiting for all cow and nocow writes after setting a block group to readonly mode. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30Btrfs: fix race between device replace and block group removalFilipe Manana
When it's finishing, the device replace code iterates all extent maps representing block group and for each one that has a stripe that refers to the source device, it replaces its device with the target device. However when it replaces the source device with the target device it, the target device still has an ID of 0ULL (BTRFS_DEV_REPLACE_DEVID), only after its ID is changed to match the one from the source device. This leads to races with the chunk removal code that can temporarly see a device with an ID of 0ULL and then attempt to use that ID to remove items from the device tree and fail, causing a transaction abort: [ 9238.594364] BTRFS info (device sdf): dev_replace from /dev/sdf (devid 3) to /dev/sde finished [ 9238.594377] ------------[ cut here ]------------ [ 9238.594402] WARNING: CPU: 14 PID: 21566 at fs/btrfs/volumes.c:2771 btrfs_remove_chunk+0x2e5/0x793 [btrfs] [ 9238.594403] BTRFS: Transaction aborted (error 1) [ 9238.594416] Modules linked in: btrfs crc32c_generic acpi_cpufreq xor tpm_tis tpm raid6_pq ppdev parport_pc processor psmouse parport i2c_piix4 evdev sg i2c_core se rio_raw pcspkr button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix virtio_pci libata virtio_ring virtio e1000 scsi_mod fl oppy [last unloaded: btrfs] [ 9238.594418] CPU: 14 PID: 21566 Comm: btrfs-cleaner Not tainted 4.6.0-rc7-btrfs-next-29+ #1 [ 9238.594419] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 9238.594421] 0000000000000000 ffff88017f1dbc60 ffffffff8126b42c ffff88017f1dbcb0 [ 9238.594422] 0000000000000000 ffff88017f1dbca0 ffffffff81052b14 00000ad37f1dbd18 [ 9238.594423] 0000000000000001 ffff88018068a558 ffff88005c4b9c00 ffff880233f60db0 [ 9238.594424] Call Trace: [ 9238.594428] [<ffffffff8126b42c>] dump_stack+0x67/0x90 [ 9238.594430] [<ffffffff81052b14>] __warn+0xc2/0xdd [ 9238.594432] [<ffffffff81052b7a>] warn_slowpath_fmt+0x4b/0x53 [ 9238.594434] [<ffffffff8116c311>] ? kmem_cache_free+0x128/0x188 [ 9238.594450] [<ffffffffa04d43f5>] btrfs_remove_chunk+0x2e5/0x793 [btrfs] [ 9238.594452] [<ffffffff8108e456>] ? arch_local_irq_save+0x9/0xc [ 9238.594464] [<ffffffffa04a26fa>] btrfs_delete_unused_bgs+0x317/0x382 [btrfs] [ 9238.594476] [<ffffffffa04a961d>] cleaner_kthread+0x1ad/0x1c7 [btrfs] [ 9238.594489] [<ffffffffa04a9470>] ? btree_invalidatepage+0x8e/0x8e [btrfs] [ 9238.594490] [<ffffffff8106f403>] kthread+0xd4/0xdc [ 9238.594494] [<ffffffff8149e242>] ret_from_fork+0x22/0x40 [ 9238.594495] [<ffffffff8106f32f>] ? kthread_stop+0x286/0x286 [ 9238.594496] ---[ end trace 183efbe50275f059 ]--- The sequence of steps leading to this is like the following: CPU 1 CPU 2 btrfs_dev_replace_finishing() at this point dev_replace->tgtdev->devid == BTRFS_DEV_REPLACE_DEVID (0ULL) ... btrfs_start_transaction() btrfs_commit_transaction() btrfs_delete_unused_bgs() btrfs_remove_chunk() looks up for the extent map corresponding to the chunk lock_chunks() (chunk_mutex) check_system_chunk() unlock_chunks() (chunk_mutex) locks fs_info->chunk_mutex btrfs_dev_replace_update_device_in_mapping_tree() --> iterates fs_info->mapping_tree and replaces the device in every extent map's map->stripes[] with dev_replace->tgtdev, which still has an id of 0ULL (BTRFS_DEV_REPLACE_DEVID) iterates over all stripes from the extent map --> calls btrfs_free_dev_extent() passing it the target device that still has an ID of 0ULL --> btrfs_free_dev_extent() fails --> aborts current transaction finishes setting up the target device, namely it sets tgtdev->devid to the value of srcdev->devid (which is necessarily > 0) frees the srcdev unlocks fs_info->chunk_mutex So fix this by taking the device list mutex while processing the stripes for the chunk's extent map. This is similar to the race between device replace and block group creation that was fixed by commit 50460e37186a ("Btrfs: fix race when finishing dev replace leading to transaction abort"). Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30Btrfs: fix race between readahead and device replace/removalFilipe Manana
The list of devices is protected by the device_list_mutex and the device replace code, in its finishing phase correctly takes that mutex before removing the source device from that list. However the readahead code was iterating that list without acquiring the respective mutex leading to crashes later on due to invalid memory accesses: [125671.831036] general protection fault: 0000 [#1] PREEMPT SMP [125671.832129] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq acpi_cpufreq tpm_tis tpm ppdev evdev parport_pc psmouse sg parport processor ser [125671.834973] CPU: 10 PID: 19603 Comm: kworker/u32:19 Tainted: G W 4.6.0-rc7-btrfs-next-29+ #1 [125671.834973] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [125671.834973] Workqueue: btrfs-readahead btrfs_readahead_helper [btrfs] [125671.834973] task: ffff8801ac520540 ti: ffff8801ac918000 task.ti: ffff8801ac918000 [125671.834973] RIP: 0010:[<ffffffff81270479>] [<ffffffff81270479>] __radix_tree_lookup+0x6a/0x105 [125671.834973] RSP: 0018:ffff8801ac91bc28 EFLAGS: 00010206 [125671.834973] RAX: 0000000000000000 RBX: 6b6b6b6b6b6b6b6a RCX: 0000000000000000 [125671.834973] RDX: 0000000000000000 RSI: 00000000000c1bff RDI: ffff88002ebd62a8 [125671.834973] RBP: ffff8801ac91bc70 R08: 0000000000000001 R09: 0000000000000000 [125671.834973] R10: ffff8801ac91bc70 R11: 0000000000000000 R12: ffff88002ebd62a8 [125671.834973] R13: 0000000000000000 R14: 0000000000000000 R15: 00000000000c1bff [125671.834973] FS: 0000000000000000(0000) GS:ffff88023fd40000(0000) knlGS:0000000000000000 [125671.834973] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [125671.834973] CR2: 000000000073cae4 CR3: 00000000b7723000 CR4: 00000000000006e0 [125671.834973] Stack: [125671.834973] 0000000000000000 ffff8801422d5600 ffff8802286bbc00 0000000000000000 [125671.834973] 0000000000000001 ffff8802286bbc00 00000000000c1bff 0000000000000000 [125671.834973] ffff88002e639eb8 ffff8801ac91bc80 ffffffff81270541 ffff8801ac91bcb0 [125671.834973] Call Trace: [125671.834973] [<ffffffff81270541>] radix_tree_lookup+0xd/0xf [125671.834973] [<ffffffffa04ae6a6>] reada_peer_zones_set_lock+0x3e/0x60 [btrfs] [125671.834973] [<ffffffffa04ae8b9>] reada_pick_zone+0x29/0x103 [btrfs] [125671.834973] [<ffffffffa04af42f>] reada_start_machine_worker+0x129/0x2d3 [btrfs] [125671.834973] [<ffffffffa04880be>] btrfs_scrubparity_helper+0x185/0x3aa [btrfs] [125671.834973] [<ffffffffa0488341>] btrfs_readahead_helper+0xe/0x10 [btrfs] [125671.834973] [<ffffffff81069691>] process_one_work+0x271/0x4e9 [125671.834973] [<ffffffff81069dda>] worker_thread+0x1eb/0x2c9 [125671.834973] [<ffffffff81069bef>] ? rescuer_thread+0x2b3/0x2b3 [125671.834973] [<ffffffff8106f403>] kthread+0xd4/0xdc [125671.834973] [<ffffffff8149e242>] ret_from_fork+0x22/0x40 [125671.834973] [<ffffffff8106f32f>] ? kthread_stop+0x286/0x286 So fix this by taking the device_list_mutex in the readahead code. We can't use here the lighter approach of using a rcu_read_lock() and rcu_read_unlock() pair together with a list_for_each_entry_rcu() call because we end up doing calls to sleeping functions (kzalloc()) in the respective code path. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30ACPI / Thermal / video: fix max_level incorrect valueAaron Lu
commit 059500940def (ACPI/video: export acpi_video_get_levels) mistakenly dropped the correct value of max_level and that caused the set_level function following failed and the acpi_video backlight interface didn't get created. Fix this by passing back the correct max_level value. While at it, also fix the param used in acpi_video_device_lcd_query_levels where acpi_handle is expected but acpi_video_device is passed. Fixes: 059500940def (ACPI/video: export acpi_video_get_levels) Reported-and-tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Signed-off-by: Aaron Lu <aaron.lu@intel.com> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-30kernel-doc: reset contents and section harderJani Nikula
If the documentation comment does not have params or sections, the section heading may leak from the previous documentation comment. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc: concatenate contents of colliding sectionsJani Nikula
If there are multiple sections with the same section name, the current implementation results in several sections by the same heading, with the content duplicated from the last section to all. Even if there's the error message, a more graceful approach is to combine all the identically named sections into one, with concatenated contents. With the supported sections already limited to select few, there are massively fewer collisions than there used to be, but this is still useful for e.g. when function parameters are documented in the middle of a documentation comment, with description spread out above and below. (This is not a recommended documentation style, but used in the kernel nonetheless.) We can now also demote the error to a warning. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc: limit the "section header:" detection to a select fewJani Nikula
kernel-doc currently identifies anything matching "section header:" (specifically a string of word characters and spaces followed by a colon) as a new section in the documentation comment, and renders the section header accordingly. Unfortunately, this turns all uses of colon into sections, mostly unintentionally. Considering the output, erroneously creating sections when not intended is always worse than erroneously not creating sections when intended. For example, a line with "http://example.com" turns into a "http" heading followed by "//example.com" in normal text style, which is quite ugly. OTOH, "WARNING: Beware of the Leopard" is just fine even if "WARNING" does not turn into a heading. It is virtually impossible to change all the kernel-doc comments, either way. The compromise is to pick the most commonly used and depended on section headers (with variants) and accept them as section headers. The accepted section headers are, case insensitive: * description: * context: * return: * returns: Additionally, case sensitive: * @return: All of the above are commonly used in the kernel-doc comments, and will result in worse output if not identified as section headers. Also, kernel-doc already has some special handling for all of them, so there's nothing particularly controversial in adding more special treatment for them. While at it, improve the whitespace handling surrounding section names. Do not consider the whitespace as part of the name. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc/rst: remove fixme commentJani Nikula
Yes, for our purposes the type should contain typedef. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc/rst: use *undescribed* instead of _undescribed_Jani Nikula
The latter isn't special to rst. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc: strip leading whitespace from continued param descsJani Nikula
If a param description spans multiple lines, check any leading whitespace in the first continuation line, and remove same amount of whitespace from following lines. This allows indentation in the multi-line parameter descriptions for aesthetical reasons while not causing accidentally significant indentation in the rst output. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc: improve handling of whitespace on the first line param descriptionJani Nikula
Handle whitespace on the first line of param text as if it was the empty string. There is no need to add the newline in this case. This improves the rst output in particular, where blank lines may be problematic in parameter lists. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc/rst: change the output layoutJani Nikula
Move away from field lists, and simply use **strong emphasis** for section headings on lines of their own. Do not use rst section headings, because their nesting depth depends on the surrounding context, which kernel-doc has no knowledge of. Also, they do not need to end up in any table of contexts or indexes. There are two related immediate benefits. Field lists are typically rendered in two columns, while the new style uses the horizontal width better. With no extra indent on the left, there's no need to be as fussy about it. Field lists are more susceptible to indentation problems than the new style. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc: strip leading blank lines from inline doc commentsJani Nikula
The inline member markup allows whitespace lines before the actual documentation starts. Strip the leading blank lines. This improves the rst output. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc/rst: blank lines in output are not neededJani Nikula
Current approach leads to two blank lines, while one is enough. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc: fix wrong code indentationJani Nikula
No functional changes. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc: do not regard $, %, or & prefixes as special in section namesJani Nikula
The use of these is confusing in the script, and per this grep, they're not used anywhere anyway: $ git grep " \* [%$&][a-zA-Z0-9_]*:" -- *.[ch] | grep -v "\$\(Id\|Revision\|Date\)" While at it, throw out the constants array, nothing is ever put there again. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc/rst: highlight function/struct/enum purpose lines tooJani Nikula
Let the user use @foo, &bar, %baz, etc. in the first kernel-doc purpose line too. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc/rst: drop redundant unescape in highlightingJani Nikula
This bit is already done by xml_unescape() above. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc/rst: add support for struct/union/enum member referencesJani Nikula
Link "&foo->bar", "&foo->bar()", "&foo.bar", and "&foo.bar()" to the struct/union/enum foo definition. The members themselves do not currently have anchors to link to, but this is better than nothing, and promotes a universal notation. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc/rst: add support for &union foo and &typedef foo referencesJani Nikula
Let the user use "&union foo" and "&typedef foo" to reference foo. The difference to using "union &foo", "typedef &foo", or just "&foo" (which are valid too) is that "union" and "typedef" become part of the link text. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc/rst: &foo references are more universal than structsJani Nikula
It's possible to use &foo to reference structs, enums, typedefs, etc. in the Sphinx C domain. Thus do not prefix the links with "struct". Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc/rst: reference functions according to C domain specJani Nikula
The Sphinx C domain spec says function references should include the parens (). Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc/rst: do not output DOC: section titles for requested onesJani Nikula
If the user requests a specific DOC: section by name, do not output its section title. In these cases, the surrounding context already has a heading, and the DOC: section title is only used as an identifier and a heading for clarity in the source file. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc: add names for output selectionJani Nikula
Make the output selection a bit more readable by adding constants for the various types of output selection. While at it, actually call the variable for choosing what to output $output_selection. No functional changes. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc: add names for states and substatesJani Nikula
Make the state machine a bit more readable by adding constants for parser states and inline member documentation parser substates. While at it, rename the "split" documentation to "inline" documentation. No functional changes. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30Documentation/sphinx: nicer referencing of struct in docbook->rst conversionJani Nikula
Add "struct" in the label of the reference. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30sphinx: update docbook->rst conversion script match C domain specJani Nikula
Function references should include the parens (), struct references should not include "struct". Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30sphinx: cheesy script to convert .tmpl filesJonathan Corbet
This script uses pandoc to convert existing DocBook template files to RST templates. A couple of sed scripts are need to massage things both before and after the conversion, but the result is then usable with no hand editing. [Jani: Change usage to tmplcvt <in> <out>. Fix escaping for docproc directives. Add support the new kernel-doc extension.] Signed-off-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30Documentation/sphinx: set version and release properlyJani Nikula
Read the version and release from the top level Makefile (for use when Sphinx is invoked directly, by e.g. Read the Docs), but override them via Sphinx command line arguments in a normal documentation build. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30Documentation/sphinx: configure the kernel-doc extensionJani Nikula
Tell Sphinx where to find the extension, and pass on the kernel src tree and kernel-doc paths to the extension. With this, any .rst files under Documentation may contain the kernel-doc rst directive to include kernel-doc documentation from any source file. While building, it may be handy to pass kernel-doc extension configuration on the command line. For example, 'make SPHINXOPTS="-D kerneldoc_verbosity=0" htmldocs' silences all stderr output from kernel-doc when the kernel-doc exit code is 0. (The stderr will be logged unconditionally when the exit code is non-zero.) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30Documentation/sphinx: add Sphinx kernel-doc directive extensionJani Nikula
Add an extension to handle kernel-doc directives, to call kernel-doc according to the arguments and parameters given to the reStructuredText directive. The syntax for the kernel-doc directive is: .. kernel-doc:: FILENAME :export: :internal: :functions: FUNCTION [FUNCTION ...] :doc: SECTION TITLE Of the directive options export, internal, functions, and doc, currently only one option may be given at a time. The FILENAME is relative from the kernel source tree root. The extension notifies Sphinx about the document dependency on FILENAME, causing the document to be rebuilt when the file has been changed. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30Documentation: add .gitignoreJani Nikula
The Sphinx output directory is generated. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30Documentation/sphinx: add basic working Sphinx configuration and buildJani Nikula
Add basic configuration and makefile to build documentation from any .rst files under Documentation using Sphinx. For starters, there's just the placeholder index.rst. At the top level Makefile, hook Sphinx documentation targets alongside (but independent of) the DocBook toolchain, having both be run on the various 'make *docs' targets. All Sphinx processing is placed into Documentation/Makefile.sphinx. Both that and the Documentation/DocBook/Makefile are now expected to handle all the documentation targets, explicitly ignoring them if they're not relevant for that particular toolchain. The changes to the existing DocBook Makefile are kept minimal. There is graceful handling of missing Sphinx and rst2pdf (which is needed for pdf output) by checking for the tool and python module, respectively, with informative messages to the user. If the Read the Docs theme (sphinx_rtd_theme) is available, use it, but otherwise gracefully fall back to the Sphinx default theme, with an informative message to the user, and slightly less pretty HTML output. Sphinx can now handle htmldocs, pdfdocs (if rst2pdf is available), epubdocs and xmldocs targets. The output documents are written into per output type subdirectories under Documentation/output. Finally, you can pass options to sphinx-build using the SPHINXBUILD make variable. For example, 'make SPHINXOPTS=-v htmldocs' for more verbose output from Sphinx. This is based on the original work by Jonathan Corbet, but he probably wouldn't recognize this as his own anymore. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc: support printing exported and non-exported symbolsJani Nikula
Currently we use docproc to figure out which symbols are exported, and then docproc calls kernel-doc on specific functions, to get documentation on exported functions. According to git blame and docproc comments, this is due to historical reasons, as functions and their corresponding EXPORT_SYMBOL* may have been in different files. However for more than ten years the recommendation in CodingStyle has been to place the EXPORT_SYMBOL* immediately after the closing function brace line. Additionally, the kernel-doc comments for functions are generally placed above the function definition in the .c files (i.e. where the EXPORT_SYMBOL* is) rather than above the declaration in the .h files. There are some exceptions to this, but AFAICT none of these are included in DocBook documentation using the "!E" docproc directive. Therefore, assuming the EXPORT_SYMBOL* and kernel-doc are with the function definition, kernel-doc can extract the exported vs. not information by making two passes on the input file. Add support for that via the new -export and -internal parameters. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30kernel-doc/rst: fix use of uninitialized valueJani Nikula
I'm not quite sure why the errors below are happening, but this fixes them. Use of uninitialized value in string ne at ./scripts/kernel-doc line 1819, <IN> line 6494. Use of uninitialized value $_[0] in join or string at ./scripts/kernel-doc line 1759, <IN> line 6494. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-30drm/doc: Unify KMS Locking docsDaniel Vetter
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Acked-by: Jani Nikula <jani.nikula@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1464599449-12509-1-git-send-email-daniel.vetter@ffwll.ch
2016-05-30drm/atomic-helper: Do not call ->mode_fixup for CRTC which will be disabledLiu Ying
When a CRTC is going to be disabled, it's state may contain a display mode with zeroed content. This could be reproduced by HDMI cable hotplug out operation with legacy fbdev support in dual display cases. It would confuse driver's CRTC callback ->mode_fixup and make the total state be rejected. So, let's don't call the callback for the CRTC. Signed-off-by: Liu Ying <gnuiyl@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1464341754-7087-1-git-send-email-gnuiyl@gmail.com
2016-05-30Fix annoyingly awkward typo in drm_edid_load.cValdis Kletnieks
Fix egregious typo in comment. Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/10576.1464589598@turing-police.cc.vt.edu
2016-05-30MAINTAINERS: Add file patterns for pinctrl device tree bindingsGeert Uytterhoeven
Submitters of device tree binding documentation may forget to CC the subsystem maintainer if this is missing. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: linux-gpio@vger.kernel.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30pinctrl: nomadik: fix inversion of gpio directionLinus Walleij
The input/output directions were inversed on the GPIO direction read function. Loose a ! and it is correct. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30gpio: flush direction status in gpiochip_lock_as_irq()Linus Walleij
As irqchip and gpiochip functions are orthogonal, the IRQ set-up or something else can have changed the direction of the GPIO line from what the GPIO descriptor knows when we get into gpiochip_lock_as_irq(). Make sure to re-read the direction setting if we have the .get_direction() callback enabled for the chip. Else we get problems like this: iio iio:device2: interrupts on the rising edge gpio gpiochip2: (8012e080.gpio): gpiochip_lock_as_irq: tried to flag a GPIO set as output for IRQ gpio gpiochip2: (8012e080.gpio): unable to lock HW IRQ 0 for IRQ genirq: Failed to request resources for l3g4200d-trigger (irq 111) on irqchip nmk1-32-63 iio iio:device2: failed to request trigger IRQ. st-gyro-i2c: probe of 2-0068 failed with error -22 Fixes: 72d320006177 ("gpio: set up initial state from .get_direction()") Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30gpio: lpc32xx: disable broken to_irq supportSylvain Lemieux
The "to_irq" functionality is broken inside this driver since commit 76ba59f8366f ("genirq: Add irq_domain-aware core IRQ handler"). The addition of the new lpc32xx irqchip driver in 4.7, fixed the lpc32xx platform interrupt issue. When switching to the new lpc32xx irqchip driver, a warning appear in the lpc32xx gpio driver: warning: "NR_IRQS" redefined. To remove this warning (temporary solution), this patch disables the broken "to_irq" mapping functionality support. Signed-off-by: Sylvain Lemieux <slemieux@tycoint.com> Acked-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30drm/imx: plane: Don't set plane->crtc in ipu_plane_update()Liu Ying
Since the drm core sets plane->crtc correctly, we don't need to do that. Signed-off-by: Liu Ying <gnuiyl@gmail.com> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-05-30drm/imx: ipuv3-plane: Constify ipu_plane_funcsLiu Ying
Signed-off-by: Liu Ying <gnuiyl@gmail.com> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-05-30drm/imx: imx-ldb: honor 'native-mode' property when selecting video mode from DTLothar Waßmann
This patch allows to select a specific video mode from a list of modes defined in DT by setting the 'native-mode' property appropriately. This change does not affect the behaviour of existing platforms, since they either: - have just one display-timings subnode - have the native-mode property pointing to the first entry - let the bootloader select the appropriate timing Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-05-30drm/imx: parallel-display: remove dead codeLothar Waßmann
The 'mode_valid' flag is never set in this driver. Remove it and the code that depends on it. Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-05-30drm/imx: use bus_flags for pixel clock polarityPhilipp Zabel
This patch allows panels to set pixel clock and data enable pin polarity other than the default of driving data at the falling pixel clock edge and active high display enable. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>