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path: root/fs/exofs/ore.c
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2012-08-02ore: Fix out-of-bounds access in _ios_obj()Boaz Harrosh1-7/+7
_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 Harrosh1-7/+1
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 Harrosh1-1/+1
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 Harrosh1-3/+3
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 Gortmaker1-0/+1
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 Harrosh1-3/+11
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 Harrosh1-8/+28
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 Harrosh1-77/+249
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 Harrosh1-5/+3
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 Harrosh1-13/+16
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 Harrosh1-0/+67
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 Harrosh1-0/+4
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 Harrosh1-7/+23
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 Harrosh1-23/+13
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 Harrosh1-37/+24
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 Harrosh1-36/+69
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 Harrosh1-1/+1
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 Harrosh1-16/+8
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 Harrosh1-15/+15
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 Sweeten1-2/+2
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 Harrosh1-0/+15
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 Harrosh1-0/+820
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>