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path: root/fs/exofs/common.h
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2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-15exofs: Write sbi->s_nextid as part of the Create commandBoaz Harrosh
Before when creating a new inode, we'd set the sb->s_dirt flag, and sometime later the system would write out s_nextid as part of the sb_info. Also on inode sync we would force the sb sync as well. Define the s_nextid as a new partition attribute and set it every time we create a new object. At mount we read it from it's new place. We now never set sb->s_dirt anywhere in exofs. write_super is actually never called. The call to exofs_write_super from exofs_put_super is also removed because the VFS always calls ->sync_fs before calling ->put_super twice. To stay backward-and-forward compatible we also write the old s_nextid in the super_block object at unmount, and support zero length attribute on mount. This also fixes a BUG where in layouts when group_width was not a divisor of EXOFS_SUPER_ID (0x10000) the s_nextid was not read from the device it was written to. Because of the sliding window layout trick, and because the read was always done from the 0 device but the write was done via the raid engine that might slide the device view. Now we read and write through the raid engine. 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>
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: 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>
2009-06-10[SCSI] libosd: osd_req_{read,write}_kern new APIBoaz Harrosh
By popular demand, define usefull wrappers for osd_req_read/write that recieve kernel pointers. All users had their own. Also remove these from exofs Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.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>