summaryrefslogtreecommitdiff
path: root/fs/ocfs2
AgeCommit message (Collapse)Author
2009-04-01mm: page_mkwrite change prototype to match faultNick Piggin
Change the page_mkwrite prototype to take a struct vm_fault, and return VM_FAULT_xxx flags. There should be no functional change. This makes it possible to return much more detailed error information to the VM (and also can provide more information eg. virtual_address to the driver, which might be important in some special cases). This is required for a subsequent fix. And will also make it easier to merge page_mkwrite() with fault() in future. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Chris Mason <chris.mason@oracle.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Artem Bityutskiy <dedekind@infradead.org> Cc: Felix Blyakher <felixb@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-27constify dentry_operations: OCFS2Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-12ocfs2: Use xs->bucket to set xattr value outsideTao Ma
A long time ago, xs->base is allocated a 4K size and all the contents in the bucket are copied to the it. Now we use ocfs2_xattr_bucket to abstract xattr bucket and xs->base is initialized to the start of the bu_bhs[0]. So xs->base + offset will overflow when the value root is stored outside the first block. Then why we can survive the xattr test by now? It is because we always read the bucket contiguously now and kernel mm allocate continguous memory for us. We are lucky, but we should fix it. So just get the right value root as other callers do. Signed-off-by: Tao Ma <tao.ma@oracle.com> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-03-12ocfs2: Fix a bug found by sparse check.Tao Ma
We need to use le32_to_cpu to test rec->e_cpos in ocfs2_dinode_insert_check. Signed-off-by: Tao Ma <tao.ma@oracle.com> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-03-12ocfs2: tweak to get the maximum inline data size with xattrTiger Yang
Replace max_inline_data with max_inline_data_with_xattr to ensure it correct when xattr inlined. Signed-off-by: Tiger Yang <tiger.yang@oracle.com> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-03-12ocfs2: reserve xattr block for new directory with inline dataTiger Yang
If this is a new directory with inline data, we choose to reserve the entire inline area for directory contents and force an external xattr block. Signed-off-by: Tiger Yang <tiger.yang@oracle.com> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-26ocfs2: add IO error check in ocfs2_get_sector()wengang wang
Check for IO error in ocfs2_get_sector(). Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-26ocfs2: set gap to seperate entry and value when xattr in bucketTiger Yang
This patch set a gap (4 bytes) between xattr entry and name/value when xattr in bucket. This gap use to seperate entry and name/value when a bucket is full. It had already been set when xattr in inode/block. Signed-off-by: Tiger Yang <tiger.yang@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-26ocfs2: lock the metaecc process for xattr bucketTao Ma
For other metadata in ocfs2, metaecc is checked in ocfs2_read_blocks with io_mutex held. While for xattr bucket, it is calculated by the whole buckets. So we have to add a spin_lock to prevent multiple processes calculating metaecc. Signed-off-by: Tao Ma <tao.ma@oracle.com> Tested-by: Tristan Ye <tristan.ye@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-26ocfs2: Use the right access_* method in ctime update of xattr.Tao Ma
In ctime updating of xattr, it use the wrong type of access for inode, so use ocfs2_journal_access_di instead. Reported-and-Tested-by: Tristan Ye <tristan.ye@oracle.com> Signed-off-by: Tao Ma <tao.ma@oracle.com> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-26ocfs2/dlm: Make dlm_assert_master_handler() kill itself instead of the asserterSunil Mushran
In dlm_assert_master_handler(), if we get an incorrect assert master from a node that, we reply with EINVAL asking the asserter to die. The problem is that an assert is sent after so many hoops, it is invariably the node that thinks the asserter is wrong, is actually wrong. So instead of killing the asserter, this patch kills the assertee. This patch papers over a race that is still being addressed. Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-26ocfs2/dlm: Use ast_lock to protect ast_listSunil Mushran
The code was using dlm->spinlock instead of dlm->ast_lock to protect the ast_list. This patch fixes the issue. Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-26ocfs2: Cleanup the lockname print in dlmglue.cSunil Mushran
The dentry lock has a different format than other locks. This patch fixes ocfs2_log_dlm_error() macro to make it print the dentry lock correctly. Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-26ocfs2/dlm: Retract fix for race between purge and migrateSunil Mushran
Mainline commit d4f7e650e55af6b235871126f747da88600e8040 attempts to delay the dlm_thread from sending the drop ref message if the lockres is being migrated. The problem is that we make the dlm_thread wait for the migration to complete. This causes a deadlock as dlm_thread also participates in the lockres migration process. A better fix for the original oss bugzilla#1012 is in testing. Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-26ocfs2: Access and dirty the buffer_head in mark_written.Tao Ma
In __ocfs2_mark_extent_written, when we meet with the situation of c_split_covers_rec, the old solution just replace the extent record and forget to access and dirty the buffer_head. This will cause a problem when the unwritten extent is in an extent block. So access and dirty it. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-10jbd2: Avoid possible NULL dereference in jbd2_journal_begin_ordered_truncate()Jan Kara
If we race with commit code setting i_transaction to NULL, we could possibly dereference it. Proper locking requires the journal pointer (to access journal->j_list_lock), which we don't have. So we have to change the prototype of the function so that filesystem passes us the journal pointer. Also add a more detailed comment about why the function jbd2_journal_begin_ordered_truncate() does what it does and how it should be used. Thanks to Dan Carpenter <error27@gmail.com> for pointing to the suspitious code. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Acked-by: Joel Becker <joel.becker@oracle.com> CC: linux-ext4@vger.kernel.org CC: ocfs2-devel@oss.oracle.com CC: mfasheh@suse.de CC: Dan Carpenter <error27@gmail.com>
2009-02-02ocfs2: add quota call to ocfs2_remove_btree_range()Mark Fasheh
We weren't reclaiming the clusters which get free'd from this function, so any user punching holes in a file would still have those bytes accounted against him/her. Add the call to vfs_dq_free_space_nodirty() to fix this. Interestingly enough, the journal credits calculation already took this into account. Signed-off-by: Mark Fasheh <mfasheh@suse.com> Acked-by: Jan Kara <jack@suse.cz>
2009-02-02ocfs2: Wakeup the downconvert thread after a successful cancel convertSunil Mushran
When two nodes holding PR locks on a resource concurrently attempt to upconvert the locks to EX, the master sends a BAST to one of the nodes. This message tells that node to first cancel convert the upconvert request, followed by downconvert to a NL. Only when this lock is downconverted to NL, can the master upconvert the first node's lock to EX. While the fs was doing the cancel convert, it was forgetting to wake up the dc thread after a successful cancel, leading to a deadlock. Reported-and-Tested-by: David Teigland <teigland@redhat.com> Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-02ocfs2: Access the xattr bucket only before modifying it.Tao Ma
In ocfs2_xattr_value_truncate, we may call b-tree codes which will extend the journal transaction. It has a potential problem that it may let the already-accessed-but-not-dirtied buffers gone. So we'd better access the bucket after we call ocfs2_xattr_value_truncate. And as for the root buffer for the xattr value, b-tree code will acess and dirty it, so we don't need to worry about it. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-02ocfs2: Fix possible deadlock in ocfs2_write_dquot()Jan Kara
It could happen that some limit has been set via quotactl() and in parallel ->mark_dirty() is called from another thread doing e.g. dquot_alloc_space(). In such case ocfs2_write_dquot() must not try to sync the dquot because that needs global quota lock but that ranks above transaction start. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-02-02ocfs2: Push out dropping of dentry lock to ocfs2_wqJan Kara
Dropping of last reference to dentry lock is a complicated operation involving dropping of reference to inode. This can get complicated and quota code in particular needs to obtain some quota locks which leads to potential deadlock. Thus we defer dropping of inode reference to ocfs2_wq. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-26Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6: ocfs2: Remove ocfs2_dquot_initialize() and ocfs2_dquot_drop() quota: Improve locking
2009-01-22fs/Kconfig: move ocfs2 outAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-01-21ocfs2: Remove ocfs2_dquot_initialize() and ocfs2_dquot_drop()Jan Kara
Since ->acquire_dquot and ->release_dquot callbacks aren't called under dqptr_sem anymore, we don't have to start a transaction and obtain locks so early. So we can just remove all this complicated stuff. Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Mark Fasheh <mfasheh@suse.de>
2009-01-08fix similar typos to successfullColy Li
When I review ocfs2 code, find there are 2 typos to "successfull". After doing grep "successfull " in kernel tree, 22 typos found totally -- great minds always think alike :) This patch fixes all the similar typos. Thanks for Randy's ack and comments. Signed-off-by: Coly Li <coyli@suse.de> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Roland Dreier <rolandd@cisco.com> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Jeff Garzik <jeff@garzik.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Vlad Yasevich <vladislav.yasevich@hp.com> Cc: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08remove lots of double-semicolonsFernando Carrijo
Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Theodore Ts'o <tytso@mit.edu> Acked-by: Mark Fasheh <mfasheh@suse.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06trivial: fix then -> than typos in comments and documentationFrederik Schwarzer
- (better, more, bigger ...) then -> (...) than Signed-off-by: Frederik Schwarzer <schwarzerf@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-01-05Merge branch 'upstream-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2 * 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2: (138 commits) ocfs2: Access the right buffer_head in ocfs2_merge_rec_left. ocfs2: use min_t in ocfs2_quota_read() ocfs2: remove unneeded lvb casts ocfs2: Add xattr support checking in init_security ocfs2: alloc xattr bucket in ocfs2_xattr_set_handle ocfs2: calculate and reserve credits for xattr value in mknod ocfs2/xattr: fix credits calculation during index create ocfs2/xattr: Always updating ctime during xattr set. ocfs2/xattr: Remove extend_trans call and add its credits from the beginning ocfs2/dlm: Fix race during lockres mastery ocfs2/dlm: Fix race in adding/removing lockres' to/from the tracking list ocfs2/dlm: Hold off sending lockres drop ref message while lockres is migrating ocfs2/dlm: Clean up errors in dlm_proxy_ast_handler() ocfs2/dlm: Fix a race between migrate request and exit domain ocfs2: One more hamming code optimization. ocfs2: Another hamming code optimization. ocfs2: Don't hand-code xor in ocfs2_hamming_encode(). ocfs2: Enable metadata checksums. ocfs2: Validate superblock with checksum and ecc. ocfs2: Checksum and ECC for directory blocks. ...
2009-01-05zero i_uid/i_gid on inode allocationAl Viro
... and don't bother in callers. Don't bother with zeroing i_blocks, while we are at it - it's already been zeroed. i_mode is not worth the effort; it has no common default value. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05ocfs2: Access the right buffer_head in ocfs2_merge_rec_left.Tao Ma
In commit "ocfs2: Use metadata-specific ocfs2_journal_access_*() functions", the wrong buffer_head is accessed. So change it to the right buffer_head. Signed-off-by: Tao Ma <tao.ma@oracle.com> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: use min_t in ocfs2_quota_read()Mark Fasheh
This is preferred to min(). Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: remove unneeded lvb castsMark Fasheh
dlmglue.c has lots of code which casts the return value of ocfs2_dlm_lvb(). This is pointless however, as ocfs2_dlm_lvb() returns void *. Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: Add xattr support checking in init_securityTiger Yang
We must check whether ocfs2 volume support xattr in init_security, if not support xattr and security is enable, would cause failure of mknod. Signed-off-by: Tiger Yang <tiger.yang@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: alloc xattr bucket in ocfs2_xattr_set_handleTiger Yang
In extreme situation, may need xattr bucket for setting security entry and acl entries during mknod. This only happens when block size is too small. Signed-off-by: Tiger Yang <tiger.yang@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: calculate and reserve credits for xattr value in mknodTiger Yang
We extend the credits for xattr's large value in set_value_outside before, this can give rise to a credits issue when we set one security entry and two acl entries duing mknod. As we remove extend_trans form set_value_outside, we must calculate and reserve the credits for xattr's large value in mknod. Signed-off-by: Tiger Yang <tiger.yang@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2/xattr: fix credits calculation during index createTao Ma
When creating a xattr index block, the old calculation forget to add credits for the meta change of the alloc file. So add more credits and more comments to explain it. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2/xattr: Always updating ctime during xattr set.Tao Ma
In xattr set, we should always update ctime if the operation goes sucessfully. The old one mistakenly put it in ocfs2_xattr_set_entry which is only called when we set xattr in inode or xattr block. The side benefit is that it resolve the bug 1052 since in that scenario, ocfs2_calc_xattr_set_need only calc out the xattr set credits while ocfs2_xattr_set_entry update the inode also which isn't concerned with the process of xattr set. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2/xattr: Remove extend_trans call and add its credits from the beginningTao Ma
Actually, when setting a new xattr value, we know it from the very beginning, and it isn't like the extension of bucket in which case we can't figure it out. So remove ocfs2_extend_trans in that function and calculate it before the transaction. It also relieve acl operation from the worry about the side effect of ocfs2_extend_trans. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2/dlm: Fix race during lockres masterySunil Mushran
dlm_get_lock_resource() is supposed to return a lock resource with a proper master. If multiple concurrent threads attempt to lookup the lockres for the same lockid while the lock mastery in underway, one or more threads are likely to return a lockres without a proper master. This patch makes the threads wait in dlm_get_lock_resource() while the mastery is underway, ensuring all threads return the lockres with a proper master. This issue is known to be limited to users using the flock() syscall. For all other fs operations, the ocfs2 dlmglue layer serializes the dlm op for each lockid. Users encountering this bug will see flock() return EINVAL and dmesg have the following error: ERROR: Dlm error "DLM_BADARGS" while calling dlmlock on resource <LOCKID>: bad api args Reported-by: Coly Li <coyli@suse.de> Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2/dlm: Fix race in adding/removing lockres' to/from the tracking listSunil Mushran
This patch adds a new lock, dlm->tracking_lock, to protect adding/removing lockres' to/from the dlm->tracking_list. We were previously using dlm->spinlock for the same, but that proved inadequate as we could be freeing a lockres from a context that did not hold that lock. As the new lock only protects this list, we can explicitly take it when removing the lockres from the tracking list. This bug was exposed when testing multiple processes concurrently flock() the same file. Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2/dlm: Hold off sending lockres drop ref message while lockres is migratingSunil Mushran
During lockres purge, o2dlm sends a drop reference message to the lockres master. This patch delays the message if the lockres is being migrated. Fixes oss bugzilla#1012 http://oss.oracle.com/bugzilla/show_bug.cgi?id=1012 Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2/dlm: Clean up errors in dlm_proxy_ast_handler()Sunil Mushran
Patch cleans printed errors in dlm_proxy_ast_handler(). The errors now includes the node number that sent the (b)ast. Also it reduces the number of endian swaps of the cookie. Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2/dlm: Fix a race between migrate request and exit domainSunil Mushran
Patch address a racing migrate request message and an exit domain message. Instead of blocking exit domains for the duration of the migrate, we ignore failure to deliver that message. This is because an exiting domain should not have any active locks and thus has no role to play in the migration. Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: One more hamming code optimization.Joel Becker
The previous optimization used a fast find-highest-bit-set operation to give us a good starting point in calc_code_bit(). This version lets the caller cache the previous code buffer bit offset. Thus, the next call always starts where the last one left off. This reduces the calculation another 39%, for a total 80% reduction from the original, naive implementation. At least, on my machine. This also brings the parity calculation to within an order of magnitude of the crc32 calculation. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: Another hamming code optimization.Joel Becker
In the calc_code_bit() function, we must find all powers of two beneath the code bit number, *after* it's shifted by those powers of two. This requires a loop to see where it ends up. We can optimize it by starting at its most significant bit. This shaves 32% off the time, for a total of 67.6% shaved off of the original, naive implementation. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: Don't hand-code xor in ocfs2_hamming_encode().Joel Becker
When I wrote ocfs2_hamming_encode(), I was following documentation of the algorithm and didn't have quite the (possibly still imperfect) grasp of it I do now. As part of this, I literally hand-coded xor. I would test a bit, and then add that bit via xor to the parity word. I can, of course, just do a single xor of the parity word and the source word (the code buffer bit offset). This cuts CPU usage by 53% on a mostly populated buffer (an inode containing utmp.h inline). Joel Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: Enable metadata checksums.Joel Becker
Add OCFS2_FEATURE_INCOMPAT_META_ECC to the list of supported features. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: Validate superblock with checksum and ecc.Joel Becker
The superblock is read via a raw call. Validate it after we find it from its signature. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: Checksum and ECC for directory blocks.Joel Becker
Use the db_check field of ocfs2_dir_block_trailer to crc/ecc the dirblocks. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: Add directory block trailers.Mark Fasheh
Future ocfs2 features metaecc and indexed directories need to store a little bit of data in each dirblock. For compatibility, we place this in a trailer at the end of the dirblock. The trailer plays itself as an empty dirent, so that if the features are turned off, it can be reused without requiring a tunefs scan. This code adds the trailer and validates it when the block is read in. [ Mark is the original author, but I reinserted this code before his dir index work. -- Joel ] Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>