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path: root/fs/xfs/xfs_sb.h
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2008-04-10[XFS] Ensure "both" features2 slots are consistentEric Sandeen
Since older kernels may look in the sb_bad_features2 slot for flags, rather than zeroing it out on fixup, we should make it equal to the sb_features2 value. Also, if the ATTR2 flag was not found prior to features2 fixup, it was not set in the mount flags, so re-check after the fixup so that the current session will use the feature. Also fix up the comments to reflect these changes. SGI-PV: 980085 SGI-Modid: xfs-linux-melb:xfs-kern:30778a Signed-off-by: Eric Sandeen <sandeen@sandeen.net> Signed-off-by: David Chinner <dgc@sgi.com> Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-10[XFS] Fix superblock features2 field alignment problemDavid Chinner
Due to the xfs_dsb_t structure not being 64 bit aligned, the last field of the on-disk superblock can vary in location This causes problems when the filesystem gets moved to a different platform, or there is a 32 bit userspace and 64 bit kernel. This patch detects the defect at mount time, logs a warning such as: XFS: correcting sb_features alignment problem in dmesg and corrects the problem so that everything is OK. it also blacklists the bad field in the superblock so it does not get used for something else later on. SGI-PV: 977636 SGI-Modid: xfs-linux-melb:xfs-kern:30539a Signed-off-by: David Chinner <dgc@sgi.com> Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Eric Sandeen <sandeen@sandeen.net> Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-10[XFS] remove shouting-indirection macros from xfs_sb.hEric Sandeen
Remove macro-to-small-function indirection from xfs_sb.h, and remove some which are completely unused. SGI-PV: 976035 SGI-Modid: xfs-linux-melb:xfs-kern:30528a Signed-off-by: Eric Sandeen <sandeen@sandeen.net> Signed-off-by: Donald Douwsma <donaldd@sgi.com> Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2007-10-15[XFS] superblock endianess annotationsChristoph Hellwig
Creates a new xfs_dsb_t that is __be annotated and keeps xfs_sb_t for the incore one. xfs_xlatesb is renamed to xfs_sb_to_disk and only handles the incore -> disk conversion. A new helper xfs_sb_from_disk handles the other direction and doesn't need the slightly hacky table-driven approach because we only ever read the full sb from disk. The handling of shared r/o filesystems has been buggy on little endian system and fixing this required shuffling around of some code in that area. SGI-PV: 968563 SGI-Modid: xfs-linux-melb:xfs-kern:29477a Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: David Chinner <dgc@sgi.com> Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-07-14[XFS] Lazy Superblock CountersDavid Chinner
When we have a couple of hundred transactions on the fly at once, they all typically modify the on disk superblock in some way. create/unclink/mkdir/rmdir modify inode counts, allocation/freeing modify free block counts. When these counts are modified in a transaction, they must eventually lock the superblock buffer and apply the mods. The buffer then remains locked until the transaction is committed into the incore log buffer. The result of this is that with enough transactions on the fly the incore superblock buffer becomes a bottleneck. The result of contention on the incore superblock buffer is that transaction rates fall - the more pressure that is put on the superblock buffer, the slower things go. The key to removing the contention is to not require the superblock fields in question to be locked. We do that by not marking the superblock dirty in the transaction. IOWs, we modify the incore superblock but do not modify the cached superblock buffer. In short, we do not log superblock modifications to critical fields in the superblock on every transaction. In fact we only do it just before we write the superblock to disk every sync period or just before unmount. This creates an interesting problem - if we don't log or write out the fields in every transaction, then how do the values get recovered after a crash? the answer is simple - we keep enough duplicate, logged information in other structures that we can reconstruct the correct count after log recovery has been performed. It is the AGF and AGI structures that contain the duplicate information; after recovery, we walk every AGI and AGF and sum their individual counters to get the correct value, and we do a transaction into the log to correct them. An optimisation of this is that if we have a clean unmount record, we know the value in the superblock is correct, so we can avoid the summation walk under normal conditions and so mount/recovery times do not change under normal operation. One wrinkle that was discovered during development was that the blocks used in the freespace btrees are never accounted for in the AGF counters. This was once a valid optimisation to make; when the filesystem is full, the free space btrees are empty and consume no space. Hence when it matters, the "accounting" is correct. But that means the when we do the AGF summations, we would not have a correct count and xfs_check would complain. Hence a new counter was added to track the number of blocks used by the free space btrees. This is an *on-disk format change*. As a result of this, lazy superblock counters are a mkfs option and at the moment on linux there is no way to convert an old filesystem. This is possible - xfs_db can be used to twiddle the right bits and then xfs_repair will do the format conversion for you. Similarly, you can convert backwards as well. At some point we'll add functionality to xfs_admin to do the bit twiddling easily.... SGI-PV: 964999 SGI-Modid: xfs-linux-melb:xfs-kern:28652a Signed-off-by: David Chinner <dgc@sgi.com> Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-09-28[XFS] Remove several macros that are no longer used anywhereEric Sandeen
SGI-PV: 955302 SGI-Modid: xfs-linux-melb:xfs-kern:26749a Signed-off-by: Eric Sandeen <sandeen@sandeen.net> Signed-off-by: Nathan Scott <nathans@sgi.com> Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-01-11[XFS] Sort out cosmetic differences between user and kernel copies of someNathan Scott
sources. SGI-PV: 907752 SGI-Modid: xfs-linux-melb:xfs-kern:24659a Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02[XFS] Update license/copyright notices to match the prefered SGINathan Scott
boilerplate. SGI-PV: 913862 SGI-Modid: xfs-linux:xfs-kern:23903a Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02[XFS] Remove xfs_macros.c, xfs_macros.h, rework headers a whole lot.Nathan Scott
SGI-PV: 943122 SGI-Modid: xfs-linux:xfs-kern:23901a Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02[XFS] Ondisk format extension for extended attributes (attr2). Basically,Nathan Scott
the data/attr forks now grow up/down from either end of the literal area, rather than dividing the literal area into two chunks and growing both upward. Means we can now make much more efficient use of the attribute space, incl. fitting DMF attributes inline in 256 byte inodes, and large jumps in dbench3 performance numbers. It is self enabling, but can be forced on/off via the attr2/noattr2 mount options. SGI-PV: 941645 SGI-Modid: xfs-linux:xfs-kern:23835a Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!