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path: root/fs/exofs/exofs.h
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2010-04-29exofs: Fix "add bdi backing to mount session" fall outBoaz Harrosh
Commit b3d0ab7e60d1865bb6f6a79a77aaba22f2543236 ("exofs: add bdi backing to mount session") has a bug in the placement of the bdi member at struct exofs_sb_info. The layout member must be kept last. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Acked-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-22exofs: add bdi backing to mount sessionJens Axboe
This ensures that dirty data gets flushed properly. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-03-05pass writeback_control to ->write_inodeChristoph Hellwig
This gives the filesystem more information about the writeback that is happening. Trond requested this for the NFS unstable write handling, and other filesystems might benefit from this too by beeing able to distinguish between the different callers in more detail. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-02-28exofs: groups supportBoaz Harrosh
* _calc_stripe_info() changes to accommodate for grouping calculations. Returns additional information * old _prepare_pages() becomes _prepare_one_group() which stores pages belonging to one device group. * New _prepare_for_striping iterates on all groups calling _prepare_one_group(). * Enable mounting of groups data_maps (group_width != 0) [QUESTION] what is faster A or B; A. x += stride; x = x % width + first_x; B x += stride if (x < last_x) x = first_x; Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28exofs: convert io_state to use pages array instead of bio at inputBoaz Harrosh
* inode.c operations are full-pages based, and not actually true scatter-gather * Lets us use more pages at once upto 512 (from 249) in 64 bit * Brings us much much closer to be able to use exofs's io_state engine from objlayout driver. (Once I decide where to put the common code) After RAID0 patch the outer (input) bio was never used as a bio, but was simply a page carrier into the raid engine. Even in the simple mirror/single-dev arrangement pages info was copied into a second bio. It is now easer to just pass a pages array into the io_state and prepare bio(s) once. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28exofs: RAID0 supportBoaz Harrosh
We now support striping over mirror devices. Including variable sized stripe_unit. Some limits: * stripe_unit must be a multiple of PAGE_SIZE * stripe_unit * stripe_count is maximum upto 32-bit (4Gb) Tested RAID0 over mirrors, RAID0 only, mirrors only. All check. Design notes: * I'm not using a vectored raid-engine mechanism yet. Following the pnfs-objects-layout data-map structure, "Mirror" is just a private case of "group_width" == 1, and RAID0 is a private case of "Mirrors" == 1. The performance lose of the general case over the particular special case optimization is totally negligible, also considering the extra code size. * In general I added a prepare_stripes() stage that divides the to-be-io pages to the participating devices, the previous exofs_ios_write/read, now becomes _write/read_mirrors and a new write/read upper layer loops on all devices calling _write/read_mirrors. Effectively the prepare_stripes stage is the all secret. Also truncate need fixing to accommodate for striping. * In a RAID0 arrangement, in a regular usage scenario, if all inode layouts will start at the same device, the small files fill up the first device and the later devices stay empty, the farther the device the emptier it is. To fix that, each inode will start at a different stripe_unit, according to it's obj_id modulus number-of-stripe-units. And will then span all stripe-units in the same incrementing order wrapping back to the beginning of the device table. We call it a stripe-units moving window. Special consideration was taken to keep all devices in a mirror arrangement identical. So a broken osd-device could just be cloned from one of the mirrors and no FS scrubbing is needed. (We do that by rotating stripe-unit at a time and not a single device at a time.) TODO: We no longer verify object_length == inode->i_size in exofs_iget. (since i_size is stripped on multiple objects now). I should introduce a multiple-device attribute reading, and use it in exofs_iget. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28exofs: Define on-disk per-inode optional layout attributeBoaz Harrosh
* Layouts describe the way a file is spread on multiple devices. The layout information is stored in the objects attribute introduced in this patch. * There can be multiple generating function for the layout. Currently defined: - No attribute present - use below moving-window on global device table, all devices. (This is the only one currently used in exofs) - an obj_id generated moving window - the obj_id is a randomizing factor in the otherwise global map layout. - An explicit layout stored, including a data_map and a device index list. - More might be defined in future ... * There are two attributes defined of the same structure: A-data-files-layout - This layout is used by data-files. If present at a directory, all files of that directory will be created with this layout. A-meta-data-layout - This layout is used by a directory and other meta-data information. Also inherited at creation of subdirectories. * At creation time inodes are created with the layout specified above. A usermode utility may change the creation layout on a give directory or file. Which in the case of directories, will also apply to newly created files/subdirectories, children of that directory. In the simple unaltered case of a newly created exofs, no layout attributes are present, and all layouts adhere to the layout specified at the device-table. * In case of a future file system loaded in an old exofs-driver. At iget(), the generating_function is inspected and if not supported will return an IO error to the application and the inode will not be loaded. So not to damage any data. Note: After this patch we do not yet support any type of layout only the RAID0 patch that enables striping at the super-block level will add support for RAID0 layouts above. This way we are past and future compatible and fully bisectable. * Access to the device table is done by an accessor since it will change according to above information. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28exofs: Move layout related members to a layout structureBoaz Harrosh
* Abstract away those members in exofs_sb_info that are related/needed by a layout into a new exofs_layout structure. Embed it in exofs_sb_info. * At exofs_io_state receive/keep a pointer to an exofs_layout. No need for an exofs_sb_info pointer, all we need is at exofs_layout. * Change any usage of above exofs_sb_info members to their new name. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28exofs: Micro-optimize exofs_i_infoBoaz Harrosh
optimize the exofs_i_info struct usage by moving the embedded vfs_inode to be first. A compiler might optimize away an "add" operation with constant zero. (Which it cannot with other constants) Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-10exofs: Multi-device mirror supportBoaz Harrosh
This patch changes on-disk format, it is accompanied with a parallel patch to mkfs.exofs that enables multi-device capabilities. After this patch, old exofs will refuse to mount a new formatted FS and new exofs will refuse an old format. This is done by moving the magic field offset inside the FSCB. A new FSCB *version* field was added. In the future, exofs will refuse to mount unmatched FSCB version. To up-grade or down-grade an exofs one must use mkfs.exofs --upgrade option before mounting. Introduced, a new object that contains a *device-table*. This object contains the default *data-map* and a linear array of devices information, which identifies the devices used in the filesystem. This object is only written to offline by mkfs.exofs. This is why it is kept separate from the FSCB, since the later is written to while mounted. Same partition number, same object number is used on all devices only the device varies. * define the new format, then load the device table on mount time make sure every thing is supported. * Change I/O engine to now support Mirror IO, .i.e write same data to multiple devices, read from a random device to spread the read-load from multiple clients (TODO: stripe read) Implementation notes: A few points introduced in previous patch should be mentioned here: * Special care was made so absolutlly all operation that have any chance of failing are done before any osd-request is executed. This is to minimize the need for a data consistency recovery, to only real IO errors. * Each IO state has a kref. It starts at 1, any osd-request executed will increment the kref, finally when all are executed the first ref is dropped. At IO-done, each request completion decrements the kref, the last one to return executes the internal _last_io() routine. _last_io() will call the registered io_state_done. On sync mode a caller does not supply a done method, indicating a synchronous request, the caller is put to sleep and a special io_state_done is registered that will awaken the caller. Though also in sync mode all operations are executed in parallel. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-10exofs: Move all operations to an io_engineBoaz Harrosh
In anticipation for multi-device operations, we separate osd operations into an abstract I/O API. Currently only one device is used but later when adding more devices, we will drive all devices in parallel according to a "data_map" that describes how data is arranged on multiple devices. The file system level operates, like before, as if there is one object (inode-number) and an i_size. The io engine will split this to the same object-number but on multiple device. At first we introduce Mirror (raid 1) layout. But at the final outcome we intend to fully implement the pNFS-Objects data-map, including raid 0,4,5,6 over mirrored devices, over multiple device-groups. And more. See: http://tools.ietf.org/html/draft-ietf-nfsv4-pnfs-obj-12 * Define an io_state based API for accessing osd storage devices in an abstract way. Usage: First a caller allocates an io state with: exofs_get_io_state(struct exofs_sb_info *sbi, struct exofs_io_state** ios); Then calles one of: exofs_sbi_create(struct exofs_io_state *ios); exofs_sbi_remove(struct exofs_io_state *ios); exofs_sbi_write(struct exofs_io_state *ios); exofs_sbi_read(struct exofs_io_state *ios); exofs_oi_truncate(struct exofs_i_info *oi, u64 new_len); And when done exofs_put_io_state(struct exofs_io_state *ios); * Convert all source files to use this new API * Convert from bio_alloc to bio_kmalloc * In io engine we make use of the now fixed osd_req_decode_sense There are no functional changes or on disk additions after this patch. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-06-21exofs: Avoid using file_fsync()Boaz Harrosh
The use of file_fsync() in exofs_file_sync() is not necessary since it does some extra stuff not used by exofs. Open code just the parts that are currently needed. TODO: Farther optimization can be done to sync the sb only on inode update of new files, Usually the sb update is not needed in exofs. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-06-21exofs: Remove IBM copyrightsBoaz Harrosh
Boaz, Congrats on getting all the OSD stuff into 2.6.30! I just pulled the git, and saw that the IBM copyrights are still there. Please remove them from all files: * Copyright (C) 2005, 2006 * International Business Machines IBM has revoked all rights on the code - they gave it to me. Thanks! Avishay Signed-off-by: Avishay Traeger <avishay@gmail.com> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31exofs: export_operationsBoaz Harrosh
implement export_operations and set in superblock. It is now posible to export exofs via nfs Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31exofs: super_operations and file_system_typeBoaz Harrosh
This patch ties all operation vectors into a file system superblock and registers the exofs file_system_type at module's load time. * The file system control block (AKA on-disk superblock) resides in an object with a special ID (defined in common.h). Information included in the file system control block is used to fill the in-memory superblock structure at mount time. This object is created before the file system is used by mkexofs.c It contains information such as: - The file system's magic number - The next inode number to be allocated Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31exofs: dir_inode and directory operationsBoaz Harrosh
implementation of directory and inode operations. * A directory is treated as a file, and essentially contains a list of <file name, inode #> pairs for files that are found in that directory. The object IDs correspond to the files' inode numbers and are allocated using a 64bit incrementing global counter. * Each file's control block (AKA on-disk inode) is stored in its object's attributes. This applies to both regular files and other types (directories, device files, symlinks, etc.). Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31exofs: address_space_operationsBoaz Harrosh
OK Now we start to read and write from osd-objects. We try to collect at most contiguous pages as possible in a single write/read. The first page index is the object's offset. TODO: In 64-bit a single bio can carry at most 128 pages. Add support of chaining multiple bios Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31exofs: symlink_inode and fast_symlink_inode operationsBoaz Harrosh
Generic implementation of symlink ops. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31exofs: file and file_inode operationsBoaz Harrosh
implementation of the file_operations and inode_operations for regular data files. Most file_operations are generic vfs implementations except: - exofs_truncate will truncate the OSD object as well - Generic file_fsync is not good for none_bd devices so open code it - The default for .flush in Linux is todo nothing so call exofs_fsync on the file. 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>