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2010-05-21quota: unify ->set_dqblkChristoph Hellwig
Pass the larger struct fs_disk_quota to the ->set_dqblk operation so that the Q_SETQUOTA and Q_XSETQUOTA operations can be implemented with a single filesystem operation and we can retire the ->set_xquota operation. The additional information (RT-subvolume accounting and warn counts) are left zero for the VFS quota implementation. Add new fieldmask values for setting the numer of blocks and inodes values which is required for the VFS quota, but wasn't for XFS. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21quota: unify ->get_dqblkChristoph Hellwig
Pass the larger struct fs_disk_quota to the ->get_dqblk operation so that the Q_GETQUOTA and Q_XGETQUOTA operations can be implemented with a single filesystem operation and we can retire the ->get_xquota operation. The additional information (RT-subvolume accounting and warn counts) are left zero for the VFS quota implementation. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-19xfs: mark xfs_iomap_write_ helpers staticChristoph Hellwig
And also drop a useless argument to xfs_iomap_write_direct. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: clean up end index calculation in xfs_page_state_convertChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: clean up mapping size calculation in __xfs_get_blocksChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: clean up xfs_iomap_validChristoph Hellwig
Rename all iomap_valid identifiers to imap_valid to fit the new world order, and clean up xfs_iomap_valid to convert the passed in offset to blocks instead of the imap values to bytes. Use the simpler inode->i_blkbits instead of the XFS macros for this. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: move I/O type flags into xfs_aops.cChristoph Hellwig
The IOMAP_ flags are now only used inside xfs_aops.c for extent probing and I/O completion tracking, so more them here, and rename them to IO_* as there's no mapping involved at all. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: kill struct xfs_iomapChristoph Hellwig
Now that struct xfs_iomap contains exactly the same units as struct xfs_bmbt_irec we can just use the latter directly in the aops code. Replace the missing IOMAP_NEW flag with a new boolean output parameter to xfs_iomap. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: report iomap_bn in block baseChristoph Hellwig
Report the iomap_bn field of struct xfs_iomap in terms of filesystem blocks instead of in terms of bytes. Shift the byte conversions into the caller, and replace the IOMAP_DELAY and IOMAP_HOLE flag checks with checks for HOLESTARTBLOCK and DELAYSTARTBLOCK. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: report iomap_offset and iomap_bsize in block baseChristoph Hellwig
Report the iomap_offset and iomap_bsize fields of struct xfs_iomap in terms of fsblocks instead of in terms of disk blocks. Shift the byte conversions into the callers temporarily, but they will disappear or get cleaned up later. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: remove iomap_deltaChristoph Hellwig
The iomap_delta field in struct xfs_iomap just contains the difference between the offset passed to xfs_iomap and the iomap_offset. Just calculate it in the only caller that cares. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: remove iomap_targetChristoph Hellwig
Instead of using the iomap_target field in struct xfs_iomap and the IOMAP_REALTIME flag just use the already existing xfs_find_bdev_for_inode helper. There's some fallout as we need to pass the inode in a few more places, which we also use to sanitize some calling conventions. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: limit xfs_imap_to_bmap to a single mappingChristoph Hellwig
We only call xfs_iomap for single mappings anyway, so remove all code dealing with multiple mappings from xfs_imap_to_bmap and add asserts that we never get results that we do not expect. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: simplify buffer to transaction matchingChristoph Hellwig
We currenly have a routine xfs_trans_buf_item_match_all which checks if any log item in a transaction contains a given buffer, and a second one that only does this check for the first, embedded chunk of log items. We only use the second routine if we know we only have that log item chunk, so get rid of the limited routine and always use the more complete one. Also rename the old xfs_trans_buf_item_match_all to xfs_trans_buf_item_match and update various surrounding comments, and move the remaining xfs_trans_buf_item_match on top of the file to avoid a forward prototype. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: Make fiemap work in query mode.Tao Ma
According to Documentation/filesystems/fiemap.txt, If fm_extent_count is zero, then the fm_extents[] array is ignored (no extents will be returned), and the fm_mapped_extents count will hold the number of extents needed. But as the commit 97db39a1f6f69e906e98118392400de5217aa33a has changed bmv_count to the caller's input buffer, this number query function can't work any more. As this commit is written to change bmv_count from MAXEXTNUM because of ENOMEM. This patch just try to set bm.bmv_count to something sane. Thanks to Dave Chinner <david@fromorbit.com> for the suggestion. Cc: Eric Sandeen <sandeen@redhat.com> Cc: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Tao Ma <tao.ma@oracle.com>
2010-05-19xfs: kill off l_sectbb_maskAlex Elder
There remains only one user of the l_sectbb_mask field in the log structure. Just kill it off and compute the mask where needed from the power-of-2 sector size. (Only update from last post is to accomodate the changes in the previous patch in the series.) Signed-off-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: record log sector size rather than log2(that)Alex Elder
Change struct log so it keeps track of the size (in basic blocks) of a log sector in l_sectBBsize rather than the log-base-2 of that value (previously, l_sectbb_log). The name was chosen for consistency with the other fields in the structure that represent a number of basic blocks. (Updated so that a variable used in computing and verifying a log's sector size is named "log2_size". Also added the "BB" to the structure field name, based on feedback from Eric Sandeen. Also dropped some superfluous parentheses.) Signed-off-by: Alex Elder <aelder@sgi.com> Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
2010-05-19xfs: remove dead XFS_LOUD_RECOVERY codeChristoph Hellwig
This can't be enabled through the build system and has been dead for ages. Note that the CRC patches add back log checksumming, but the code is quite different from the version removed here anyway. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <david@fromorbit.com>
2010-05-19xfs: removed unused XFS_QMOPT_ flagsChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <david@fromorbit.com>
2010-05-19xfs: remove a few macro indirections in the quota codeChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <david@fromorbit.com>
2010-05-19xfs: access quotainfo structure directlyChristoph Hellwig
Access fields in m_quotainfo directly instead of hiding them behind the XFS_QI_* macros. Add local variables for the quotainfo pointer in places where we have lots of them. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <david@fromorbit.com>
2010-05-19xfs: wait for direct I/O to complete in fsync and write_inodeChristoph Hellwig
We need to wait for all pending direct I/O requests before taking care of metadata in fsync and write_inode. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <david@fromorbit.com>
2010-05-19xfs: xfs_trace.c: duplicated includeAndrea Gelmini
fs/xfs/linux-2.6/xfs_trace.c: xfs_attr_sf.h is included more than once. Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: minor odds and ends in xfs_log_recover.cAlex Elder
Odds and ends in "xfs_log_recover.c". This patch just contains some minor things that didn't seem to warrant their own individual patches: - In xlog_bread_noalign(), drop an assertion that a pointer is non-null (the crash will tell us it was a bad pointer). - Add a more descriptive header comment for xlog_find_verify_cycle(). - Make a few additions to the comments in xlog_find_head(). Also rearrange some expressions in a few spots to produce the same result, but in a way that seems more clear what's being computed. (Updated in response to Dave's review comments. Note I did not split this patch like I said I would.) Signed-off-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: avoid repeated pointer dereferencesAlex Elder
In xlog_find_cycle_start() use a local variable for some repeated operations rather than constantly accessing the memory location whose address is passed in. (This version drops an assertion that a pointer is non-null.) Signed-off-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: change a few labels in xfs_log_recover.cAlex Elder
Rename a label used in xlog_find_head() that I thought was poorly chosen. Also combine two adjacent labels xlog_find_tail() into a single label, and give it a more generic name. (Now using Dave's suggested "validate_head" name for first label.) Signed-off-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: enforce synchronous writes in xfs_bwriteChristoph Hellwig
xfs_bwrite is used with the intention of synchronously writing out buffers, but currently it does not actually clear the async flag if that's left from previous writes but instead implements async behaviour if it finds it. Remove the code handling asynchronous writes as we've got rid of those entirely outside of the log and delwri buffers, and make sure that we clear the async and read flags before writing the buffer. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: remove periodic superblock writebackChristoph Hellwig
All modifications to the superblock are done transactional through xfs_trans_log_buf, so there is no reason to initiate periodic asynchronous writeback. This only removes the superblock from the delwri list and will lead to sub-optimal I/O scheduling. Cut down xfs_sync_fsdata now that it's only used for synchronous superblock writes and move the log coverage checks into the two callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-19xfs: make the log ticket transaction id randomDave Chinner
The transaction ID that is written to the log for a transaction is currently set by taking the lower 32 bits of the memory address of the ticket structure. This is not guaranteed to be unique as tickets comes from a slab and slots can be reallocated immediately after being freed. As a result, there is no guarantee of uniqueness in the ticket ID value. Fix this by assigning a random number to the ticket ID field so that it is extremely unlikely that duplicates will occur and remove the possibility of transactions being mixed up during recovery due to duplicate IDs. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: nothing special about 1-block log sectorAlex Elder
There are a number of places where a log sector size of 1 uses special case code. The round_up() and round_down() macros produce the correct result even when the log sector size is 1, and this eliminates the need for treating this as a special case. Signed-off-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: encapsulate bbcount validity checkingAlex Elder
Define a function that encapsulates checking the validity of a log block count. (Updated from previous version--no longer includes error reporting in the encapsulated validation function.) Signed-off-by: Alex Elder <aelder@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <dchinner@redhat.com>
2010-05-19xfs: kill XLOG_SECTOR_ROUND*()Alex Elder
XLOG_SECTOR_ROUNDUP_BBCOUNT() and XLOG_SECTOR_ROUNDDOWN_BLKNO() are now fairly simple macro translations. Just get rid of them in favor of the round_up() and round_down() macro calls they represent. Also, in spots in xlog_get_bp() and xlog_write_log_records(), round_up() was being called with value 1, which just evaluates to the macro's second argument; so just use that instead. In the latter case, make use of that value, as long as it's already been computed. Signed-off-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com>
2010-05-19xfs: simplify XLOG_SECTOR_ROUND*()Alex Elder
XLOG_SECTOR_ROUNDUP_BBCOUNT() is defined in "fs/xfs/xfs_log_recover.c" in an overly-complicated way. It is basically roundup(), but that is not at all clear from its definition. (Actually, there is another macro round_up() that applies for power-of-two-based masks which I'll be using here.) The operands in XLOG_SECTOR_ROUNDUP_BBCOUNT() are basically the block number (bbs) and the log sector basic block mask (log->l_sectbb_mask). I'll call them B and M for this discussion. The macro computes is value this way: M && (B & M) ? (B + M + 1) & ~M : B Put another way, we can break it into 3 cases: 1) ! M -> B # 0 mask, no effect 2) ! (B & M) -> B # sector aligned 3) M && (B & M) -> (B + M + 1) & ~M # round up otherwise The round_up() macro is cleverly defined using a value, v, and a power-of-2, p, and the result is the nearest multiple of p greater than or equal to v. Its value is computed something like this: ((v - 1) | (p - 1)) + 1 Let's consider using this in the context of the 3 cases above. When p = 2^0 = 1, the result boils down to ((v - 1) | 0) + 1, so it just translates any value v to itself. That handles case (1) above. When p = 2^n, n > 0, we know that (p - 1) will be a mask with all n bits 0..n-1 set. The condition in this case occurs when none of those mask bits is set in the value v provided. If that is the case, subtracting 1 from v will have 1's in all those lower bits (at least). Therefore, OR-ing the mask with that decremented value has no effect, so adding the 1 back again will just translate the v to itself. This handles case (2). Otherwise, the value v is greater than some multiple of p, and decrementing it will produce a result greater than or equal to that multiple. OR-ing in the mask will produce a value 1 less than the next multiple of p, so finally adding 1 back will result in the desired rounded-up value. This handles case (3). Hopefully this is convincing. While I was at it, I converted XLOG_SECTOR_ROUNDDOWN_BLKNO() to use the round_down() macro. Signed-off-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com>
2010-05-19xfs: fix min bufsize bugs in two placesAlex Elder
This fixes a bug in two places that I found by inspection. In xlog_find_verify_cycle() and xlog_write_log_records(), the code attempts to allocate a buffer to hold as many blocks as possible. It gives up if the number of blocks to be allocated gets too small. Right now it uses log->l_sectbb_log as that lower bound, but I'm sure it's supposed to be the actual log sector size instead. That is, the lower bound should be (1 << log->l_sectbb_log). Also define a simple macro xlog_sectbb(log) to represent the number of basic blocks in a sector for the given log. (No change from original submission; I have implemented Christoph's suggestion about storing l_sectsize rather than l_sectbb_log in a new, separate patch in this series.) Signed-off-by: Alex Elder <aelder@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <dchinner@redhat.com>
2010-05-19xfs: add const qualifiers to xfs error function argsAlex Elder
Change the tag and file name arguments to xfs_error_report() and xfs_corruption_error() to use a const qualifier. Signed-off-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com>
2010-05-19xfs: remove xfs_dqmarkerChristoph Hellwig
The xfs_dqmarker structure does not need to exist anymore. Move the remaining flags field out of it and remove the structure altogether. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <david@fromorbit.com>
2010-05-19xfs: convert the dquot free list to use list headsDave Chinner
Convert the dquot free list on the filesystem to use listhead infrastructure rather than the roll-your-own in the quota code. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: convert the dquot hash list to use list headsDave Chinner
Convert the dquot hash list on the filesystem to use listhead infrastructure rather than the roll-your-own in the quota code. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: remove duplicate code from dquot reclaimDave Chinner
The dquot shaker and the free-list reclaim code use exactly the same algorithm but the code is duplicated and slightly different in each case. Make the shaker code use the single dquot reclaim code to remove the code duplication. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: convert the per-mount dquot list to use list headsDave Chinner
Convert the dquot list on the filesytesm to use listhead infrastructure rather than the roll-your-own in the quota code. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: add log item recovery tracingDave Chinner
Currently there is no tracing in log recovery, so it is difficult to determine what is going on when something goes wrong. Add tracing for log item recovery to provide visibility into the log recovery process. The tracing added shows regions being extracted from the log transactions and added to the transaction hash forming recovery items, followed by the reordering, cancelling and finally recovery of the items. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: clean up xlog_write_adv_cntChristoph Hellwig
Replace the awkward xlog_write_adv_cnt with an inline helper that makes it more obvious that it's modifying it's paramters, and replace the use of an integer type for "ptr" with a real void pointer. Also move xlog_write_adv_cnt to xfs_log_priv.h as it will be used outside of xfs_log.c in the delayed logging series. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-05-19xfs: introduce new internal log vector structureDave Chinner
The current log IO vector structure is a flat array and not extensible. To make it possible to keep separate log IO vectors for individual log items, we need a method of chaining log IO vectors together. Introduce a new log vector type that can be used to wrap the existing log IO vectors on use that internally to the log. This means that the existing external interface (xfs_log_write) does not change and hence no changes to the transaction commit code are required. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-05-19xfs: reindent xlog_writeChristoph Hellwig
Reindent xlog_write to normal one tab indents and move all variable declarations into the closest enclosing block. Split from a bigger patch by Dave Chinner. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-05-19xfs: factor xlog_writeDave Chinner
xlog_write is a mess that takes a lot of effort to understand. It is a mass of nested loops with 4 space indents to get it to fit in 80 columns and lots of funky variables that aren't obvious what they mean or do. Break it down into understandable chunks. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-05-19xfs: log ticket reservation underestimates the number of iclogsDave Chinner
When allocation a ticket for a transaction, the ticket is initialised with the worst case log space usage based on the number of bytes the transaction may consume. Part of this calculation is the number of log headers required for the iclog space used up by the transaction. This calculation makes an undocumented assumption that if the transaction uses the log header space reservation on an iclog, then it consumes either the entire iclog or it completes. That is - the transaction that is first in an iclog is the transaction that the log header reservation is accounted to. If the transaction is larger than the iclog, then it will use the entire iclog itself. Document this assumption. Further, the current calculation uses the rule that we can fit iclog_size bytes of transaction data into an iclog. This is in correct - the amount of space available in an iclog for transaction data is the size of the iclog minus the space used for log record headers. This means that the calculation is out by 512 bytes per 32k of log space the transaction can consume. This is rarely an issue because maximally sized transactions are extremely uncommon, and for 4k block size filesystems maximal transaction reservations are about 400kb. Hence the error in this case is less than the size of an iclog, so that makes it even harder to hit. However, anyone using larger directory blocks (16k directory blocks push the maximum transaction size to approx. 900k on a 4k block size filesystem) or larger block size (e.g. 64k blocks push transactions to the 3-4MB size) could see the error grow to more than an iclog and at this point the transaction is guaranteed to get a reservation underrun and shutdown the filesystem. Fix this by adjusting the calculation to calculate the correct number of iclogs required and account for them all up front. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: Clean up xfs_trans_committed code after factoringDave Chinner
Now that the code has been factored, clean up all the remaining style cruft, simplify the code and re-order functions so that it doesn't need forward declarations. Also move the remaining functions that require forward declarations (xfs_trans_uncommit, xfs_trans_free) so that all the forward declarations can be removed from the file. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: update and factor xfs_trans_committed()Dave Chinner
The function header to xfs-trans_committed has long had this comment: * THIS SHOULD BE REWRITTEN TO USE xfs_trans_next_item() To prepare for different methods of committing items, convert the code to use xfs_trans_next_item() and factor the code into smaller, more digestible chunks. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19xfs: clean up xfs_trans_commit logic even moreChristoph Hellwig
> +shut_us_down: > + shutdown = XFS_FORCED_SHUTDOWN(mp) ? EIO : 0; > + if (!(tp->t_flags & XFS_TRANS_DIRTY) || shutdown) { > + xfs_trans_unreserve_and_mod_sb(tp); > + /* This whole area in _xfs_trans_commit is still a complete mess. So while touching this code, unravel this mess as well to make the whole flow of the function simpler and clearer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <david@fromorbit.com>
2010-05-19xfs: split out iclog writing from xfs_trans_commit()Dave Chinner
Split the the part of xfs_trans_commit() that deals with writing the transaction into the iclog into a separate function. This isolates the physical commit process from the logical commit operation and makes it easier to insert different transaction commit paths without affecting the existing algorithm adversely. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>