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path: root/fs/exofs/super.c
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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: 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: 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>
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>
2009-12-10exofs: statfs blocks is sectors not FS blocksBoaz Harrosh
Even though exofs has a 4k block size, statfs blocks is in sectors (512 bytes). Also if target returns 0 for capacity then make it ULLONG_MAX. df does not like zero-size filesystems Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-10exofs: Prints on mount and unmoutBoaz Harrosh
It is important to print in the logs when a filesystem was mounted and eventually unmounted. Print the osd-device's osd_name and pid the FS was mounted/unmounted on. TODO: How to also print the namespace path the filesystem was mounted on? Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-09-24exofs: remove BKL from super operationsBoaz Harrosh
the two places inside exofs that where taking the BKL were: exofs_put_super() - .put_super and exofs_sync_fs() - which is .sync_fs and is also called from .write_super. Now exofs_sync_fs() is protected from itself by also taking the sb_lock. exofs_put_super() directly calls exofs_sync_fs() so there is no danger between these two either. In anyway there is absolutely nothing dangerous been done inside exofs_sync_fs(). Unless there is some subtle race with the actual lifetime of the super_block in regard to .put_super and some other parts of the VFS. Which is highly unlikely. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-07-12headers: smp_lock.h reduxAlexey Dobriyan
* Remove smp_lock.h from files which don't need it (including some headers!) * Add smp_lock.h to files which do need it * Make smp_lock.h include conditional in hardirq.h It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT This will make hardirq.h inclusion cheaper for every PREEMPT=n config (which includes allmodconfig/allyesconfig, BTW) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
2009-06-11exofs: add ->sync_fsChristoph Hellwig
Add a ->sync_fs method for data integrity syncs, and reimplement ->write_super ontop of it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11->write_super lock_super pushdownChristoph Hellwig
Push down lock_super into ->write_super instances and remove it from the caller. Following filesystem don't need ->s_lock in ->write_super and are skipped: * bfs, nilfs2 - no other uses of s_lock and have internal locks in ->write_super * ext2 - uses BKL in ext2_write_super and has internal calls without s_lock * reiserfs - no other uses of s_lock as has reiserfs_write_lock (BKL) in ->write_super * xfs - no other uses of s_lock and uses internal lock (buffer lock on superblock buffer) to serialize ->write_super. Also xfs_fs_write_super is superflous and will go away in the next merge window Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11push BKL down into ->put_superChristoph Hellwig
Move BKL into ->put_super from the only caller. A couple of filesystems had trivial enough ->put_super (only kfree and NULLing of s_fs_info + stuff in there) to not get any locking: coda, cramfs, efs, hugetlbfs, omfs, qnx4, shmem, all others got the full treatment. Most of them probably don't need it, but I'd rather sort that out individually. Preferably after all the other BKL pushdowns in that area. [AV: original used to move lock_super() down as well; these changes are removed since we don't do lock_super() at all in generic_shutdown_super() now] [AV: fuse, btrfs and xfs are known to need no damn BKL, exempt] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11remove ->write_super call in generic_shutdown_superChristoph Hellwig
We just did a full fs writeout using sync_filesystem before, and if that's not enough for the filesystem it can perform it's own writeout in ->put_super, which many filesystems already do. Move a call to foofs_write_super into every foofs_put_super for now to guarantee identical behaviour until it's cleaned up by the individual filesystem maintainers. Exceptions: - affs already has identical copy & pasted code at the beginning of affs_put_super so no need to do it twice. - xfs does the right thing without it and I have changes pending for the xfs tree touching this are so I don't really need conflicts here.. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>