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path: root/fs/exofs/Kconfig
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2012-01-06ore: FIX breakage when MISC_FILESYSTEMS is not setBoaz Harrosh
As Reported by Randy Dunlap When MISC_FILESYSTEMS is not enabled and NFS4.1 is: fs/built-in.o: In function `objio_alloc_io_state': objio_osd.c:(.text+0xcb525): undefined reference to `ore_get_rw_state' fs/built-in.o: In function `_write_done': objio_osd.c:(.text+0xcb58d): undefined reference to `ore_check_io' fs/built-in.o: In function `_read_done': ... When MISC_FILESYSTEMS, which is more of a GUI thing then anything else, is not selected. exofs/Kconfig is never examined during Kconfig, and it can not do it's magic stuff to automatically select everything needed. We must split exofs/Kconfig in two. The ore one is always included. And the exofs one is left in it's old place in the menu. [Needed for the 3.2.0 Kernel] CC: Stable Tree <stable@kernel.org> Reported-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-11-02pnfs-obj: move to ore 02: move to OREBoaz Harrosh
In this patch we are actually moving to the ORE. (Object Raid Engine). objio_state holds a pointer to an ore_io_state. Once we have an ore_io_state at hand we can call the ore for reading/writing. We register on the done path to kick off the nfs io_done mechanism. Again for Ease of reviewing the old code is "#if 0" but is not removed so the diff command works better. The old code will be removed in the next patch. fs/exofs/Kconfig::ORE is modified to also be auto-included if PNFS_OBJLAYOUT is set. Since we now depend on ORE. (See comments in fs/exofs/Kconfig) Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.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>
2011-08-06ore: 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>
2009-03-31exofs: Kbuild, Headers and osd utilsBoaz Harrosh
This patch includes osd infrastructure that will be used later by the file system. Also the declarations of constants, on disk structures, and prototypes. And the Kbuild+Kconfig files needed to build the exofs module. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>