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2013-10-23xfs: decouple inode and bmap btree header filesDave Chinner
Currently the xfs_inode.h header has a dependency on the definition of the BMAP btree records as the inode fork includes an array of xfs_bmbt_rec_host_t objects in it's definition. Move all the btree format definitions from xfs_btree.h, xfs_bmap_btree.h, xfs_alloc_btree.h and xfs_ialloc_btree.h to xfs_format.h to continue the process of centralising the on-disk format definitions. With this done, the xfs inode definitions are no longer dependent on btree header files. The enables a massive culling of unnecessary includes, with close to 200 #include directives removed from the XFS kernel code base. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-23xfs: decouple log and transaction headersDave Chinner
xfs_trans.h has a dependency on xfs_log.h for a couple of structures. Most code that does transactions doesn't need to know anything about the log, but this dependency means that they have to include xfs_log.h. Decouple the xfs_trans.h and xfs_log.h header files and clean up the includes to be in dependency order. In doing this, remove the direct include of xfs_trans_reserve.h from xfs_trans.h so that we remove the dependency between xfs_trans.h and xfs_mount.h. Hence the xfs_trans.h include can be moved to the indicate the actual dependencies other header files have on it. Note that these are kernel only header files, so this does not translate to any userspace changes at all. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-23xfs: create a shared header file for format-related informationDave Chinner
All of the buffer operations structures are needed to be exported for xfs_db, so move them all to a common location rather than spreading them all over the place. They are verifying the on-disk format, so while xfs_format.h might be a good place, it is not part of the on disk format. Hence we need to create a new header file that we centralise these related definitions. Start by moving the bffer operations structures, and then also move all the other definitions that have crept into xfs_log_format.h and xfs_format.h as there was no other shared header file to put them in. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-30xfs: check correct status variable for xfs_inobt_get_rec() callBrian Foster
The call to xfs_inobt_get_rec() in xfs_dialloc_ag() passes 'j' as the output status variable. The immediately following XFS_WANT_CORRUPTED_GOTO() checks the value of 'i,' which is from the previous lookup call and has already been checked. Fix the corruption check to use 'j.' Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-20xfs: fix the comment of xfs_ialloc_ag_select()Zhi Yong Wu
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-12xfs: fix issues that cause userspace warningsDave Chinner
Some of the code shared with userspace causes compilation warnings from things turned off in the kernel code, such as differences in variable signedness. Fix those issues. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-12xfs: move unrelated definitions out of xfs_inode.hDave Chinner
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-06-27xfs: Use inode create transactionDave Chinner
Replace the use of buffer based logging of inode initialisation, uses the new logical form to describe the range to be initialised in recovery. We continue to "log" the inode buffers to push them into the AIL and ensure that the inode create transaction is not removed from the log before the inode buffers are written to disk. Update the transaction identifier and reservations to match the changed implementation. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-06-27xfs: Inode create item recoveryDave Chinner
When we find a icreate transaction, we need to get and initialise the buffers in the range that has been passed. Extract and verify the information in the item record, then loop over the range initialising and issuing the buffer writes delayed. Support an arbitrary size range to initialise so that in future when we allocate inodes in much larger chunks all kernels that understand this transaction can still recover them. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-06-26xfs: Remove the left function variable from xfs_ialloc_get_rec()Jie Liu
This patch clean out the left function variable as it is useless to xfs_ialloc_get_rec(). Signed-off-by: Jie Liu <jeff.liu@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-04-27xfs: buffer type overruns blf_flags fieldDave Chinner
The buffer type passed to log recvoery in the buffer log item overruns the blf_flags field. I had assumed that flags field was a 32 bit value, and it turns out it is a unisgned short. Therefore having 19 flags doesn't really work. Convert the buffer type field to numeric value, and use the top 5 bits of the flags field for it. We currently have 17 types of buffers, so using 5 bits gives us plenty of room for expansion in future.... Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-04-21xfs: add version 3 inode format with CRCsChristoph Hellwig
Add a new inode version with a larger core. The primary objective is to allow for a crc of the inode, and location information (uuid and ino) to verify it was written in the right place. We also extend it by: a creation time (for Samba); a changecount (for NFSv4); a flush sequence (in LSN format for recovery); an additional inode flags field; and some additional padding. These additional fields are not implemented yet, but already laid out in the structure. [dchinner@redhat.com] Added LSN and flags field, some factoring and rework to capture all the necessary information in the crc calculation. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-04-21xfs: add CRC checks to the AGIDave Chinner
Same set of changes made to the AGF need to be made to the AGI. This patch has a similar history to the AGF, hence a similar sign-off chain. Signed-off-by: Dave Chinner <dgc@sgi.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dgc@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-03-07xfs: rename random32() to prandom_u32()Akinobu Mita
Use more preferable function name which implies using a pseudo-random number generator. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: <bpm@sgi.com> Cc: Ben Myers <bpm@sgi.com> Cc: Alex Elder <elder@kernel.org> Cc: xfs@oss.sgi.com Signed-off-by: Ben Myers <bpm@sgi.com>
2013-01-03xfs: don't zero structure members after a memset(0)Eric Sandeen
Commit 408cc4e97a3ccd172d2d676e4b585badf439271b added memset(0, ...) to allocation args structures, so there is no need to explicitly set any of the fields to 0 after that. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-26xfs: inode allocation should use unmapped buffers.Dave Chinner
Inode buffers do not need to be mapped as inodes are read or written directly from/to the pages underlying the buffer. This fixes a regression introduced by commit 611c994 ("xfs: make XBF_MAPPED the default behaviour"). Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15xfs: convert buffer verifiers to an ops structure.Dave Chinner
To separate the verifiers from iodone functions and associate read and write verifiers at the same time, introduce a buffer verifier operations structure to the xfs_buf. This avoids the need for assigning the write verifier, clearing the iodone function and re-running ioend processing in the read verifier, and gets rid of the nasty "b_pre_io" name for the write verifier function pointer. If we ever need to, it will also be easier to add further content specific callbacks to a buffer with an ops structure in place. We also avoid needing to export verifier functions, instead we can simply export the ops structures for those that are needed outside the function they are defined in. This patch also fixes a directory block readahead verifier issue it exposed. This patch also adds ops callbacks to the inode/alloc btree blocks initialised by growfs. These will need more work before they will work with CRCs. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15xfs: connect up write verifiers to new buffersDave Chinner
Metadata buffers that are read from disk have write verifiers already attached to them, but newly allocated buffers do not. Add appropriate write verifiers to all new metadata buffers. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15xfs: add pre-write metadata buffer verifier callbacksDave Chinner
These verifiers are essentially the same code as the read verifiers, but do not require ioend processing. Hence factor the read verifier functions and add a new write verifier wrapper that is used as the callback. This is done as one large patch for all verifiers rather than one patch per verifier as the change is largely mechanical. This includes hooking up the write verifier via the read verifier function. Hooking up the write verifier for buffers obtained via xfs_trans_get_buf() will be done in a separate patch as that touches code in many different places rather than just the verifier functions. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15xfs: verify AGI blocks as they are read from diskDave Chinner
Add an AGI block verify callback function and pass it into the buffer read functions. Remove the now redundant verification code that is currently in use. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15xfs: make buffer read verication an IO completion functionDave Chinner
Add a verifier function callback capability to the buffer read interfaces. This will be used by the callers to supply a function that verifies the contents of the buffer when it is read from disk. This patch does not provide callback functions, but simply modifies the interfaces to allow them to be called. The reason for adding this to the read interfaces is that it is very difficult to tell fom the outside is a buffer was just read from disk or whether we just pulled it out of cache. Supplying a callbck allows the buffer cache to use it's internal knowledge of the buffer to execute it only when the buffer is read from disk. It is intended that the verifier functions will mark the buffer with an EFSCORRUPTED error when verification fails. This allows the reading context to distinguish a verification error from an IO error, and potentially take further actions on the buffer (e.g. attempt repair) based on the error reported. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-02xfs: Update inode alloc commentsCarlos Maiolino
I found some out of date comments while studying the inode allocation code, so I believe it's worth to have these comments updated. It basically rewrites the comment regarding to "call_again" variable, which is not used anymore, but instead, callers of xfs_ialloc() decides if it needs to be called again relying only if ialloc_context is NULL or not. Also did some small changes in another comment that I thought to be pertinent to the current behaviour of these functions and some alignment on both comments. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-18xfs: zero allocation_args on the kernel stackMark Tinguely
Zero the kernel stack space that makes up the xfs_alloc_arg structures. Signed-off-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-09-26xfs: Fix m_agirotor reset during AG selectionCarlos Maiolino
xfs_ialloc_next_ag() currently resets m_agirotor when it is equal to m_maxagi: if (++mp->m_agirotor == mp->m_maxagi) mp->m_agirotor = 0; But, if for some reason mp->m_maxagi changes to a lower value than current m_agirotor, this condition will never be true, causing m_agirotor to exceed the maximum allowed value (m_maxagi). This implies mainly during lookups for xfs_perag structs in its radix tree, since the agno value used for the lookup is based on m_agirotor. An out-of-range m_agirotor may cause a lookup failure which in case will return NULL. As an example, the value of m_maxagi is decreased during inode64->inode32 remount process, case where I've found this problem. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-08-16xfs: unlock the AGI buffer when looping in xfs_diallocChristoph Hellwig
Also update some commens in the area to make the code easier to read. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-07-29xfs: do not read the AGI buffer in xfs_dialloc until nessecaryChristoph Hellwig
Refactor the AG selection loop in xfs_dialloc to operate on the in-memory perag data as much as possible. We only read the AGI buffer once we have selected an AG to allocate inodes now instead of for every AG considered. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-07-29xfs: refactor xfs_ialloc_ag_selectChristoph Hellwig
Loop over the in-core perag structures and prefer using pagi_freecount over going out to the AGI buffer where possible. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-07-29xfs: add a short cut to xfs_dialloc for the non-NULL agbp caseChristoph Hellwig
In this case we already have selected an AG and know it has free space beause the buffer lock never got released. Jump directly into xfs_dialloc_ag and short cut the AG selection loop. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-07-29xfs: remove the alloc_done argument to xfs_diallocChristoph Hellwig
We can simplify check the IO_agbp pointer for being non-NULL instead of passing another argument through two layers of function calls. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-07-29xfs: split xfs_diallocChristoph Hellwig
Move the actual allocation once we have selected an allocation group into a separate helper, and make xfs_dialloc a wrapper around it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-07-22xfs: remove xfs_ialloc_find_freeChristoph Hellwig
This function is entirely trivial and only has one caller, so remove it to simplify the code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: clean up xfs_bit.h includesDave Chinner
With the removal of xfs_rw.h and other changes over time, xfs_bit.h is being included in many files that don't actually need it. Clean up the includes as necessary. Also move the only-used-once xfs_ialloc_find_free() static inline function out of a header file that is widely included to reduce the number of needless dependencies on xfs_bit.h. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: kill XBF_LOCKDave Chinner
Buffers are always returned locked from the lookup routines. Hence we don't need to tell the lookup routines to return locked buffers, on to try and lock them. Remove XBF_LOCK from all the callers and from internal buffer cache usage. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-03xfs: propagate umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-10-11xfs: remove XFS_BUF_SET_VTYPE and XFS_BUF_SET_VTYPE_REFChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: Check the return value of xfs_trans_get_buf()Chandra Seetharaman
Check the return value of xfs_trans_get_buf() and fail appropriately. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-07-25xfs: Remove the macro XFS_BUF_ERROR and familyChandra Seetharaman
Remove the definitions and usage of the macros XFS_BUF_ERROR, XFS_BUF_GETERROR and XFS_BUF_ISERROR. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-07-08xfs: byteswap constants instead of variablesChristoph Hellwig
Micro-optimize various comparisms by always byteswapping the constant instead of the variable, which allows to do the swap at compile instead of runtime. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2011-03-07xfs: Convert remaining cmn_err() callers to new APIDave Chinner
Once converted, kill the remainder of the cmn_err() interface. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-03-07xfs: convert xfs_fs_cmn_err to new error logging APIDave Chinner
Continue to clean up the error logging code by converting all the callers of xfs_fs_cmn_err() to the new API. Once done, remove the unused old API function. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-10-18xfs: remove xfs_buf wrappersChristoph Hellwig
Stop having two different names for many buffer functions and use the more descriptive xfs_buf_* names directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-08-24xfs: fix untrusted inode number lookupDave Chinner
Commit 7124fe0a5b619d65b739477b3b55a20bf805b06d ("xfs: validate untrusted inode numbers during lookup") changes the inode lookup code to do btree lookups for untrusted inode numbers. This change made an invalid assumption about the alignment of inodes and hence incorrectly calculated the first inode in the cluster. As a result, some inode numbers were being incorrectly considered invalid when they were actually valid. The issue was not picked up by the xfstests suite because it always runs fsr and dump (the two utilities that utilise the bulkstat interface) on cache hot inodes and hence the lookup code in the cold cache path was not sufficiently exercised to uncover this intermittent problem. Fix the issue by relaxing the btree lookup criteria and then checking if the record returned contains the inode number we are lookup for. If it we get an incorrect record, then the inode number is invalid. Cc: <stable@kernel.org> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-07-26xfs: remove unneeded #include statementsChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <david@fromorbit.com>
2010-07-26xfs: drop dmapi hooksChristoph Hellwig
Dmapi support was never merged upstream, but we still have a lot of hooks bloating XFS for it, all over the fast pathes of the filesystem. This patch drops over 700 lines of dmapi overhead. If we'll ever get HSM support in mainline at least the namespace events can be done much saner in the VFS instead of the individual filesystem, so it's not like this is much help for future work. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-06-24xfs: remove block number from inode lookup codeDave Chinner
The block number comes from bulkstat based inode lookups to shortcut the mapping calculations. We ar enot able to trust anything from bulkstat, so drop the block number as well so that the correct lookups and mappings are always done. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-06-24xfs: rename XFS_IGET_BULKSTAT to XFS_IGET_UNTRUSTEDDave Chinner
Inode numbers may come from somewhere external to the filesystem (e.g. file handles, bulkstat information) and so are inherently untrusted. Rename the flag we use for these lookups to make it obvious we are doing a lookup of an untrusted inode number and need to verify it completely before trying to read it from disk. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-06-24xfs: validate untrusted inode numbers during lookupDave Chinner
When we decode a handle or do a bulkstat lookup, we are using an inode number we cannot trust to be valid. If we are deleting inode chunks from disk (default noikeep mode), then we cannot trust the on disk inode buffer for any given inode number to correctly reflect whether the inode has been unlinked as the di_mode nor the generation number may have been updated on disk. This is due to the fact that when we delete an inode chunk, we do not write the clusters back to disk when they are removed - instead we mark them stale to avoid them being written back potentially over the top of something that has been subsequently allocated at that location. The result is that we can have locations of disk that look like they contain valid inodes but in reality do not. Hence we cannot simply convert the inode number to a block number and read the location from disk to determine if the inode is valid or not. As a result, and XFS_IGET_BULKSTAT lookup needs to actually look the inode up in the inode allocation btree to determine if the inode number is valid or not. It should be noted even on ikeep filesystems, there is the possibility that blocks on disk may look like valid inode clusters. e.g. if there are filesystem images hosted on the filesystem. Hence even for ikeep filesystems we really need to validate that the inode number is valid before issuing the inode buffer read. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-21xfs: remove duplicate buffer flagsChristoph Hellwig
Currently we define aliases for the buffer flags in various namespaces, which only adds confusion. Remove all but the XBF_ flags to clean this up a bit. Note that we still abuse XFS_B_ASYNC/XBF_ASYNC for some non-buffer uses, but I'll clean that up later. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-15xfs: Replace per-ag array with a radix treeDave Chinner
The use of an array for the per-ag structures requires reallocation of the array when growing the filesystem. This requires locking access to the array to avoid use after free situations, and the locking is difficult to get right. To avoid needing to reallocate an array, change the per-ag structures to an allocated object per ag and index them using a tree structure. The AGs are always densely indexed (hence the use of an array), but the number supported is 2^32 and lookups tend to be random and hence indexing needs to scale. A simple choice is a radix tree - it works well with this sort of index. This change also removes another large contiguous allocation from the mount/growfs path in XFS. The growing process now needs to change to only initialise the new AGs required for the extra space, and as such only needs to exclusively lock the tree for inserts. The rest of the code only needs to lock the tree while doing lookups, and hence this will remove all the deadlocks that currently occur on the m_perag_lock as it is now an innermost lock. The lock is also changed to a spinlock from a read/write lock as the hold time is now extremely short. To complete the picture, the per-ag structures will need to be reference counted to ensure that we don't free/modify them while they are still in use. This will be done in subsequent patch. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-15xfs: convert remaining direct references to m_peragDave Chinner
Convert the remaining direct lookups of the per ag structures to use get/put accesses. Ensure that the loops across AGs and prior users of the interface balance gets and puts correctly. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>