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path: root/fs/exofs/ore.c
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2014-10-19Boaz Harrosh - Fix broken email addressBoaz Harrosh
I no longer have access to the Panasas email. So change to an email that can always reach me. Signed-off-by: Boaz Harrosh <ooo@electrozaur.com>
2014-05-22ore: Support for raid 6Boaz Harrosh
This simple patch adds support for raid6 to the ORE. Most operations and calculations where already for the general case. Only things left: * call async_gen_syndrome() in the case of raid6 (NOTE that the raid6 math is the one supported by the Linux Kernel see: crypto/async_tx/async_pq.c) * call _ore_add_parity_unit() twice with only last call generating the redundancy pages. * Fix couple BUGS in old code a. In reads when parity==2 it can happen that per_dev->length=0 but per_dev->offset was set and adjusted by _ore_add_sg_seg(). Don't let it be overwritten. b. The all 'cur_comp > starting_dev' thing to determine if: "per_dev->offset is in the current stripe number or the next one." Was a complete raid5/4 accident. When parity==2 this is not at all true usually. All we need to do is increment si->ob_offset once we pass by the first parity device. (This also greatly simplifies the code, amen) c. Calculation of si->dev rotation can overflow when parity==2. * Then last enable raid6 in ore_verify_layout() I want to deeply thank Daniel Gryniewicz who found first all the bugs in the old raid code, and inspired these patches: Inspired-by Daniel Gryniewicz <dang@linuxbox.com> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2014-05-22ore: Remove redundant dev_order(), more cleanupsBoaz Harrosh
Two cleanups: * si->cur_comp, si->cur_pg where always calculated after the call to ore_calc_stripe_info() with the help of _dev_order(...). But these are already calculated by ore_calc_stripe_info() and can be just set there. (This is left over from the time that si->cur_comp, si->cur_pg were only used by raid code, but now the main loop manages them anyway even though they are ultimately not used in none raid code) * si->cur_comp - For the very last stripe case, was set inside _ore_add_parity_unit(). This is not clear and will be wrong for coming raid6 so move this to only caller. Now si->cur_comp is only manipulated within _prepare_for_striping(), always next to the manipulation of cur_dev. Which is much easier to understand and follow. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2014-05-22ore: (trivial) reformat some codeBoaz Harrosh
rearrange some source lines. Nothing changed. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2014-01-23ore: Don't crash on NULL bio in _clear_bioBoaz Harrosh
In the case of target returning OSD_ERR_PRI_CLEAR_PAGES when we only sent for attributes don't crash on NULL bio. This is an osd-target bug but don't crash regardless Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2014-01-23ore: Fix wrong math in allocation of per device BIOBoaz Harrosh
At IO preparation we calculate the max pages at each device and allocate a BIO per device of that size. The calculation was wrong on some unaligned corner cases offset/length combination and would make prepare return with -ENOMEM. This would be bad for pnfs-objects that would in that case IO through MDS. And fatal for exofs were it would fail writes with EIO. Fix it by doing the proper math, that will work in all cases. (I ran a test with all possible offset/length combinations this time round). Also when reading we do not need to allocate for the parity units since we jump over them. Also lower the max_io_length to take into account the parity pages so not to allocate BIOs bigger than PAGE_SIZE CC: Stable Kernel <stable@vger.kernel.org> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2013-03-23block: Add bio_for_each_segment_all()Kent Overstreet
__bio_for_each_segment() iterates bvecs from the specified index instead of bio->bv_idx. Currently, the only usage is to walk all the bvecs after the bio has been advanced by specifying 0 index. For immutable bvecs, we need to split these apart; bio_for_each_segment() is going to have a different implementation. This will also help document the intent of code that's using it - bio_for_each_segment_all() is only legal to use for code that owns the bio. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: Neil Brown <neilb@suse.de> CC: Boaz Harrosh <bharrosh@panasas.com>
2012-09-09block: Add bio_clone_bioset(), bio_clone_kmalloc()Kent Overstreet
Previously, there was bio_clone() but it only allocated from the fs bio set; as a result various users were open coding it and using __bio_clone(). This changes bio_clone() to become bio_clone_bioset(), and then we add bio_clone() and bio_clone_kmalloc() as wrappers around it, making use of the functionality the last patch adedd. This will also help in a later patch changing how bio cloning works. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: NeilBrown <neilb@suse.de> CC: Alasdair Kergon <agk@redhat.com> CC: Boaz Harrosh <bharrosh@panasas.com> CC: Jeff Garzik <jeff@garzik.org> Acked-by: Jeff Garzik <jgarzik@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-08-02ore: Fix out-of-bounds access in _ios_obj()Boaz Harrosh
_ios_obj() is accessed by group_index not device_table index. The oc->comps array is only a group_full of devices at a time it is not like ore_comp_dev() which is indexed by a global device_table index. This did not BUG until now because exofs only uses a single COMP for all devices. But with other FSs like PanFS this is not true. This bug was only in the write_path, all other users were using it correctly [This is a bug since 3.2 Kernel] CC: Stable Tree <stable@kernel.org> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2012-07-20ore: Remove support of partial IO request (NFS crash)Boaz Harrosh
Do to OOM situations the ore might fail to allocate all resources needed for IO of the full request. If some progress was possible it would proceed with a partial/short request, for the sake of forward progress. Since this crashes NFS-core and exofs is just fine without it just remove this contraption, and fail. TODO: Support real forward progress with some reserved allocations of resources, such as mem pools and/or bio_sets [Bug since 3.2 Kernel] CC: Stable Tree <stable@kernel.org> CC: Benny Halevy <bhalevy@tonian.com> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2012-01-06ore: fix BUG_ON, too few sgs when readingBoaz Harrosh
When reading RAID5 files, in rare cases, we calculated too few sg segments. There should be two extra for the beginning and end partial units. Also "too few sg segments" should not be a BUG_ON there is all the mechanics in place to handle it, as a short read. So just return -ENOMEM and the rest of the code will gracefully split the IO. [Bug in 3.2.0 Kernel] CC: Stable Tree <stable@kernel.org> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2012-01-06ore: Fix crash in case of an IO error.Boaz Harrosh
The users of ore_check_io() expect the reported device (In case of error) to be indexed relative to the passed-in ore_components table, and not the logical dev index. This causes a crash inside objlayoutdriver in case of an IO error. [Bug in 3.2.0 Kernel] CC: Stable Tree <stable@kernel.org> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-31fs: add module.h to files that were implicitly using itPaul Gortmaker
Some files were using the complete module.h infrastructure without actually including the header at all. Fix them up in advance so once the implicit presence is removed, we won't get failures like this: CC [M] fs/nfsd/nfssvc.o fs/nfsd/nfssvc.c: In function 'nfsd_create_serv': fs/nfsd/nfssvc.c:335: error: 'THIS_MODULE' undeclared (first use in this function) fs/nfsd/nfssvc.c:335: error: (Each undeclared identifier is reported only once fs/nfsd/nfssvc.c:335: error: for each function it appears in.) fs/nfsd/nfssvc.c: In function 'nfsd': fs/nfsd/nfssvc.c:555: error: implicit declaration of function 'module_put_and_exit' make[3]: *** [fs/nfsd/nfssvc.o] Error 1 Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-24ore: Enable RAID5 mountsBoaz Harrosh
Now that we support raid5 Enable it at mount. Raid6 will come next raid4 is not demanded for so it will probably not be enabled. (Until some one wants it) NOTE: That mkfs.exofs had support for raid5/6 since long time ago. (Making an empty raidX FS is just as easy as raid0 ;-} ) Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-24ore: RAID5 WriteBoaz Harrosh
This is finally the RAID5 Write support. The bigger part of this patch is not the XOR engine itself, But the read4write logic, which is a complete mini prepare_for_striping reading engine that can read scattered pages of a stripe into cache so it can be used for XOR calculation. That is, if the write was not stripe aligned. The main algorithm behind the XOR engine is the 2 dimensional array: struct __stripe_pages_2d. A drawing might save 1000 words --- __stripe_pages_2d | n = pages_in_stripe_unit; w = group_width - parity; | pages array presented to the XOR lib | | V | __1_page_stripe[0].pages --> [c0][c1]..[cw][c_par] <---| | | __1_page_stripe[1].pages --> [c0][c1]..[cw][c_par] <--- | ... | ... | __1_page_stripe[n].pages --> [c0][c1]..[cw][c_par] ^ | data added columns first then row --- The pages are put on this array columns first. .i.e: p0-of-c0, p1-of-c0, ... pn-of-c0, p0-of-c1, ... So we are doing a corner turn of the pages. Note that pages will zigzag down and left. but are put sequentially in growing order. So when the time comes to XOR the stripe, only the beginning and end of the array need be checked. We scan the array and any NULL spot will be field by pages-to-be-read. The FS that wants to support RAID5 needs to supply an operations-vector that searches a given page in cache, and specifies if the page is uptodate or need reading. All these pages to be read are put on a slave ore_io_state and synchronously read. All the pages of a stripe are read in one IO, using the scatter gather mechanism. In write we constrain our IO to only be incomplete on a single stripe. Meaning either the complete IO is within a single stripe so we might have pages to read from both beginning or end of the strip. Or we have some reading to do at beginning but end at strip boundary. The left over pages are pushed to the next IO by the API already established by previous work, where an IO offset/length combination presented to the ORE might get the length truncated and the user must re-submit the leftover pages. (Both exofs and NFS support this) But any ORE user should make it's best effort to align it's IO before hand and avoid complications. A cached ore_layout->stripe_size member can be used for that calculation. (NOTE: that ORE demands that stripe_size may not be bigger then 32bit) What else? Well read it and tell me. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-24ore: RAID5 readBoaz Harrosh
This patch introduces the first stage of RAID5 support mainly the skip-over-raid-units when reading. For writes it inserts BLANK units, into where XOR blocks should be calculated and written to. It introduces the new "general raid maths", and the main additional parameters and components needed for raid5. Since at this stage it could corrupt future version that actually do support raid5. The enablement of raid5 mounting and setting of parity-count > 0 is disabled. So the raid5 code will never be used. Mounting of raid5 is only enabled later once the basic XOR write is also in. But if the patch "enable RAID5" is applied this code has been tested to be able to properly read raid5 volumes and is according to standard. Also it has been tested that the new maths still properly supports RAID0 and grouping code just as before. (BTW: I have found more bugs in the pnfs-obj RAID math fixed here) The ore.c file is getting too big, so new ore_raid.[hc] files are added that will include the special raid stuff that are not used in striping and mirrors. In future write support these will get bigger. When adding the ore_raid.c to Kbuild file I was forced to rename ore.ko to libore.ko. Is it possible to keep source file, say ore.c and module file ore.ko the same even if there are multiple files inside ore.ko? Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-24ore: Make ore_calc_stripe_info EXPORT_SYMBOLBoaz Harrosh
ore_calc_stripe_info is needed by exofs::export.c for the layout calculations. Make it exportable Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-14ore/exofs: Change ore_check_io APIBoaz Harrosh
Current ore_check_io API receives a residual pointer, to report partial IO. But it is actually not used, because in a multiple devices IO there is never a linearity in the IO failure. On the other hand if every failing device is reported through a received callback measures can be taken to handle only failed devices. One at a time. This will also be needed by the objects-layout-driver for it's error reporting facility. Exofs is not currently using the new information and keeps the old behaviour of failing the complete IO in case of an error. (No partial completion) TODO: Use an ore_check_io callback to set_page_error only the failing pages. And re-dirty write pages. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-14ore/exofs: Define new ore_verify_layoutBoaz Harrosh
All users of the ore will need to check if current code supports the given layout. For example RAID5/6 is not currently supported. So move all the checks from exofs/super.c to a new ore_verify_layout() to be used by ore users. Note that any new layout should be passed through the ore_verify_layout() because the ore engine will prepare and verify some internal members of ore_layout, and assumes it's called. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-14ore: Support for partial component tableBoaz Harrosh
Users like the objlayout-driver would like to only pass a partial device table that covers the IO in question. For example exofs divides the file into raid-group-sized chunks and only serves group_width number of devices at a time. The partiality is communicated by setting ore_componets->first_dev and the array covers all logical devices from oc->first_dev upto (oc->first_dev + oc->numdevs) The ore_comp_dev() API receives a logical device index and returns the actual present device in the table. An out-of-range dev_index will BUG. Logical device index is the theoretical device index as if all the devices of a file are present. .i.e: total_devs = group_width * mirror_p1 * group_count 0 <= dev_index < total_devs Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-14ore: Support for short read/writesBoaz Harrosh
Memory conditions and max_bio constraints might cause us to not comply to the full length of the requested IO. Instead of failing the complete IO we can issue a shorter read/write and report how much was actually executed in the ios->length member. All users must check ios->length at IO_done or upon return of ore_read/write and re-issue the reminder of the bytes. Because other wise there is no error returned like before. This is part of the effort to support the pnfs-obj layout driver. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-14ore: Remove check for ios->kern_buff in _prepare_for_striping to laterBoaz Harrosh
Move the check and preparation of the ios->kern_buff case to later inside _write_mirror(). Since read was never used with ios->kern_buff its support is removed instead of fixed. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-14ore: cleanup: Embed an ore_striping_info inside ore_io_stateBoaz Harrosh
Now that each ore_io_state covers only a single raid group. A single striping_info math is needed. Embed one inside ore_io_state to cache the calculation results and eliminate an extra call. Also the outer _prepare_for_striping is removed since it does nothing. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-14ore: Only IO one group at a time (API change)Boaz Harrosh
Usually a single IO is confined to one group of devices (group_width) and at the boundary of a raid group it can spill into a second group. Current code would allocate a full device_table size array at each io_state so it can comply to requests that span two groups. Needless to say that is very wasteful, specially when device_table count can get very large (hundreds even thousands), while a group_width is usually 8 or 10. * Change ore API to trim on IO that spans two raid groups. The user passes offset+length to ore_get_rw_state, the ore might trim on that length if spanning a group boundary. The user must check ios->length or ios->nrpages to see how much IO will be preformed. It is the responsibility of the user to re-issue the reminder of the IO. * Modify exofs To copy spilled pages on to the next IO. This means one last kick is needed after all coalescing of pages is done. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-04ore/exofs: Change the type of the devices array (API change)Boaz Harrosh
In the pNFS obj-LD the device table at the layout level needs to point to a device_cache node, where it is possible and likely that many layouts will point to the same device-nodes. In Exofs we have a more orderly structure where we have a single array of devices that repeats twice for a round-robin view of the device table This patch moves to a model that can be used by the pNFS obj-LD where struct ore_components holds an array of ore_dev-pointers. (ore_dev is newly defined and contains a struct osd_dev *od member) Each pointer in the array of pointers will point to a bigger user-defined dev_struct. That can be accessed by use of the container_of macro. In Exofs an __alloc_dev_table() function allocates the ore_dev-pointers array as well as an exofs_dev array, in one allocation and does the addresses dance to set everything pointing correctly. It still keeps the double allocation trick for the inodes round-robin view of the table. The device table is always allocated dynamically, also for the single device case. So it is unconditionally freed at umount. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-03ore: Make ore_striping_info and ore_calc_stripe_info publicBoaz Harrosh
The struct ore_striping_info will be used later in other structures. And ore_calc_stripe_info as well. Rename them make struct ore_striping_info public. ore_calc_stripe_info is still static, will be made public on first use. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-03exofs: Rename struct ore_components comps => ocBoaz Harrosh
ore_components already has a comps member so this leads to things like comps->comps which is annoying. the name oc was already used in new code. So rename all old usage of ore_components comps => ore_components oc. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-10-03exofs/ore.c: local functions should be staticH Hartley Sweeten
This quiets the sparse noise: warning: symbol '_calc_trunk_info' was not declared. Should it be static? Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-08-06ore: Make ore its own moduleBoaz Harrosh
Export everything from ore need exporting. Change Kbuild and Kconfig to build ore.ko as an independent module. Import ore from exofs Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-08-06exofs: Rename raid engine from exofs/ios.c => oreBoaz Harrosh
ORE stands for "Objects Raid Engine" This patch is a mechanical rename of everything that was in ios.c and its API declaration to an ore.c and an osd_ore.h header. The ore engine will later be used by the pnfs objects layout driver. * File ios.c => ore.c * Declaration of types and API are moved from exofs.h to a new osd_ore.h * All used types are prefixed by ore_ from their exofs_ name. * Shift includes from exofs.h to osd_ore.h so osd_ore.h is independent, include it from exofs.h. Other than a pure rename there are no other changes. Next patch will move the ore into it's own module and will export the API to be used by exofs and later the layout driver Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>