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path: root/fs/exofs/exofs.h
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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>