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2011-07-23fs/9p: add 9P2000.L unlinkat operationAneesh Kumar K.V
unlinkat - Remove a directory entry size[4] Tunlinkat tag[2] dirfid[4] name[s] flag[4] size[4] Runlinkat tag[2] older Tremove have the below request format size[4] Tremove tag[2] fid[4] The remove message is used to remove a directory entry either file or directory The remove opreation is actually a directory opertation and should ideally have dirfid, if not we cannot represent the fid on server with anything other than name. We will have to derive the directory name from fid in the Tremove request. NOTE: The operation doesn't clunk the unlink fid. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-23fs/9p: add 9P2000.L renameat operationAneesh Kumar K.V
renameat - change name of file or directory size[4] Trenameat tag[2] olddirfid[4] oldname[s] newdirfid[4] newname[s] size[4] Rrenameat tag[2] older Trename have the below request format size[4] Trename tag[2] fid[4] newdirfid[4] name[s] The rename message is used to change the name of a file, possibly moving it to a new directory. The rename opreation is actually a directory opertation and should ideally have olddirfid, if not we cannot represent the fid on server with anything other than name. We will have to derive the old directory name from fid in the Trename request. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-23fs/9p: Always ask new inode in createAneesh Kumar K.V
This make sure we don't end up reusing the unlinked inode object. The ideal way is to use inode i_generation. But i_generation is not available in userspace always. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-23fs/9p: Fix invalid mount options/argsPrem Karat
Without this fix, if any invalid mount options/args are passed while mouting the 9p fs, no error (-EINVAL) is returned and default arg value is assigned. This fix returns -EINVAL when an invalid arguement is found while parsing mount options. Signed-off-by: Prem Karat <prem.karat@linux.vnet.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-23fs/9p: When doing inode lookup compare qid details and inode mode bits.Aneesh Kumar K.V
This make sure we don't use wrong inode from the inode hash. The inode number of the file deleted is reused by the next file system object created and if we only use inode number for inode hash lookup we could end up with wrong struct inode. Also compare inode generation number. Not all Linux file system provide st_gen in userspace. So it could be 0; Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-23fs/9p: remove rename work around in 9pAneesh Kumar K.V
Now that VFS does the right thing remove the work around. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-22Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (107 commits) vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filp isofs: Remove global fs lock jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory fix IN_DELETE_SELF on overwriting rename() on ramfs et.al. mm/truncate.c: fix build for CONFIG_BLOCK not enabled fs:update the NOTE of the file_operations structure Remove dead code in dget_parent() AFS: Fix silly characters in a comment switch d_add_ci() to d_splice_alias() in "found negative" case as well simplify gfs2_lookup() jfs_lookup(): don't bother with . or .. get rid of useless dget_parent() in btrfs rename() and link() get rid of useless dget_parent() in fs/btrfs/ioctl.c fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers drivers: fix up various ->llseek() implementations fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek Ext4: handle SEEK_HOLE/SEEK_DATA generically Btrfs: implement our own ->llseek fs: add SEEK_HOLE and SEEK_DATA flags reiserfs: make reiserfs default to barrier=flush ... Fix up trivial conflicts in fs/xfs/linux-2.6/xfs_super.c due to the new shrinker callout for the inode cache, that clashed with the xfs code to start the periodic workers later.
2011-07-22vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filpKonstantin Khlebnikov
Replace unclear (struct dentry *) to (struct file *) typecast with ERR_CAST() macro. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-22isofs: Remove global fs lockJan Kara
sbi->s_mutex isn't needed for isofs at all so we can just remove it. Generally, since isofs is always mounted read-only, filesystem structure cannot change under us. So buffer_head contents stays constant after it's filled in. That leaves us with possible changes of global data structures. Superblock changes only during filesystem mount (even remount does not change it), inodes are only filled in during reading from disk. So there are no changes of these structures to bother about. Arguments why sbi->s_mutex can be removed at each place: isofs_readdir: Accesses sb, inode, filp, local variables => s_mutex not needed isofs_lookup: Protected by directory's i_mutex. Accesses sb, inode, dentry, local variables => s_mutex not needed rock_ridge_symlink_readpage: Protected by page lock. Accesses sb, inode, local variables => s_mutex not needed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-22jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directoryAl Viro
We don't generate IN_DELETE_SELF on victim of overwriting rename() if it happens to be a directory. Trivially fixed by doing to ->i_nlink what we do ->pino_nlink a couple of lines later in jffs2_rename(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-22fix IN_DELETE_SELF on overwriting rename() on ramfs et.al.Al Viro
On ramfs and other simple_rename() users IN_DELETE_SELF is not generated for victim of overwriting rename() if it's is a directory. Works on most of the local filesystems and really trivial to fix... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-22Merge branch 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/miscLinus Torvalds
* 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc: (39 commits) ptrace: do_wait(traced_leader_killed_by_mt_exec) can block forever ptrace: fix ptrace_signal() && STOP_DEQUEUED interaction connector: add an event for monitoring process tracers ptrace: dont send SIGSTOP on auto-attach if PT_SEIZED ptrace: mv send-SIGSTOP from do_fork() to ptrace_init_task() ptrace_init_task: initialize child->jobctl explicitly has_stopped_jobs: s/task_is_stopped/SIGNAL_STOP_STOPPED/ ptrace: make former thread ID available via PTRACE_GETEVENTMSG after PTRACE_EVENT_EXEC stop ptrace: wait_consider_task: s/same_thread_group/ptrace_reparented/ ptrace: kill real_parent_is_ptracer() in in favor of ptrace_reparented() ptrace: ptrace_reparented() should check same_thread_group() redefine thread_group_leader() as exit_signal >= 0 do not change dead_task->exit_signal kill task_detached() reparent_leader: check EXIT_DEAD instead of task_detached() make do_notify_parent() __must_check, update the callers __ptrace_detach: avoid task_detached(), check do_notify_parent() kill tracehook_notify_death() make do_notify_parent() return bool ptrace: s/tracehook_tracer_task()/ptrace_parent()/ ...
2011-07-22Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds
* 'for-linus' of git://oss.sgi.com/xfs/xfs: (49 commits) xfs: add size update tracepoint to IO completion xfs: convert AIL cursors to use struct list_head xfs: remove confusing ail cursor wrapper xfs: use a cursor for bulk AIL insertion xfs: failure mapping nfs fh to inode should return ESTALE xfs: Remove the second parameter to xfs_sb_count() xfs: remove the dead XFS_DABUF_DEBUG code xfs: remove leftovers of the old btree tracing code xfs: remove the dead QUOTADEBUG code xfs: remove the unused xfs_buf_delwri_sort function xfs: remove wrappers around b_iodone xfs: remove wrappers around b_fspriv xfs: add a proper transaction pointer to struct xfs_buf xfs: factor out xfs_da_grow_inode_int xfs: factor out xfs_dir2_leaf_find_stale xfs: cleanup struct xfs_dir2_free xfs: reshuffle dir2 headers xfs: start periodic workers later Revert "xfs: fix filesystsem freeze race in xfs_trans_alloc" xfs: remove variables that serve no purpose in xfs_alloc_ag_vextent_exact() ...
2011-07-22Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm: dlm: don't limit active work items dlm: use workqueue for callbacks dlm: remove deadlock debug print dlm: improve rsb searches dlm: keep lkbs in idr dlm: fix kmalloc args dlm: don't do pointless NULL check, use kzalloc and fix order of arguments dlm: dump address of unknown node dlm: use vmalloc for hash tables dlm: show addresses in configfs
2011-07-22Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hch/hfsplus * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/hfsplus: hfsplus: ensure bio requests are not smaller than the hardware sectors hfsplus: Add additional range check to handle on-disk corruptions hfsplus: Add error propagation for hfsplus_ext_write_extent_locked hfsplus: add error checking for hfs_find_init() hfsplus: lift the 2TB size limit hfsplus: fix overflow in hfsplus_read_wrapper hfsplus: fix overflow in hfsplus_get_block hfsplus: assignments inside `if' condition clean-up
2011-07-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmwLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw: GFS2: combine duplicated block freeing routines GFS2: Add S_NOSEC support GFS2: Automatically adjust glock min hold time GFS2: Cache dir hash table in a contiguous buffer
2011-07-22Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6Linus Torvalds
* 'linux-next' of git://git.infradead.org/ubifs-2.6: (32 commits) MAINTAINERS: change e-mail of Adrian Hunter UBIFS: fix master node recovery UBIFS: improve power cut emulation testing UBIFS: rename recovery testing variables UBIFS: remove custom list of superblocks UBIFS: stop re-defining UBI operations UBIFS: switch to I/O helpers UBIFS: switch to ubifs_leb_write UBIFS: switch to ubifs_leb_read UBIFS: introduce more I/O helpers UBIFS: always print stacktrace when switching to R/O mode UBIFS: remove unused and unneeded debugging function UBIFS: add global debugfs knobs UBIFS: introduce debugfs helpers UBIFS: re-arrange debugging code a bit UBIFS: be more informative in failure mode UBIFS: switch self-check knobs to debugfs UBIFS: lessen amount of debugging check types UBIFS: introduce helper functions for debugging checks and tests UBIFS: amend debugging inode size check function prototype ...
2011-07-22hfsplus: ensure bio requests are not smaller than the hardware sectorsSeth Forshee
Currently all bio requests are 512 bytes, which may fail for media whose physical sector size is larger than this. Ensure these requests are not smaller than the block device logical block size. BugLink: http://bugs.launchpad.net/bugs/734883 Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-07-22hfsplus: Add additional range check to handle on-disk corruptionsNaohiro Aota
'recoff' is read from disk and used for an argument to memcpy, so if the value read from disk is larger than the page size, it result to "general protection fault". This patch add additional range check for the value, so that disk fuzz won't cause such fault. Signed-off-by: Naohiro Aota <naota@elisp.net> Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-07-22ptrace: do_wait(traced_leader_killed_by_mt_exec) can block foreverOleg Nesterov
Test-case: void *tfunc(void *arg) { execvp("true", NULL); return NULL; } int main(void) { int pid; if (fork()) { pthread_t t; kill(getpid(), SIGSTOP); pthread_create(&t, NULL, tfunc, NULL); for (;;) pause(); } pid = getppid(); assert(ptrace(PTRACE_ATTACH, pid, 0,0) == 0); while (wait(NULL) > 0) ptrace(PTRACE_CONT, pid, 0,0); return 0; } It is racy, exit_notify() does __wake_up_parent() too. But in the likely case it triggers the problem: de_thread() does release_task() and the old leader goes away without the notification, the tracer sleeps in do_wait() without children/tracees. Change de_thread() to do __wake_up_parent(traced_leader->parent). Since it is already EXIT_DEAD we can do this without ptrace_unlink(), EXIT_DEAD threads do not exist from do_wait's pov. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org>
2011-07-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: CIFS: Fix wrong length in cifs_iovec_read
2011-07-21vfs: drop conditional inode prefetch in __do_lookup_rcuLinus Torvalds
It seems to hurt performance in real life. Yes, the inode will be used later, but the conditional doesn't seem to predict all that well (negative dentries are not uncommon) and it looks like the cost of prefetching is simply higher than depending on the cache doing the right thing. As usual. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-21FS-Cache: Fix __fscache_uncache_all_inode_pages()'s outer loopJan Beulich
The compiler, at least for ix86 and m68k, validly warns that the comparison: next <= (loff_t)-1 is always true (and it's always true also for x86-64 and probably all other arches - as long as pgoff_t isn't wider than loff_t). The intention appears to be to avoid wrapping of "next", so rather than eliminating the pointless comparison, fix the loop to indeed get exited when "next" would otherwise wrap. On m68k the following warning is observed: fs/fscache/page.c: In function '__fscache_uncache_all_inode_pages': fs/fscache/page.c:979: warning: comparison is always false due to limited range of data type Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Reported-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: David Howells <dhowells@redhat.com> Cc: Suresh Jayaraman <sjayaraman@suse.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-21CIFS: Fix wrong length in cifs_iovec_readPavel Shilovsky
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-07-20Remove dead code in dget_parent()Al Viro
->d_parent is never NULL... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20AFS: Fix silly characters in a commentDavid Howells
Fix silly characters in a comment in AFS code (some weird characters replaced the word 'flag' some point way back). Reported-by: viro@ZenIV.linux.org.uk Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20switch d_add_ci() to d_splice_alias() in "found negative" case as wellAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20simplify gfs2_lookup()Al Viro
d_splice_alias() will DTRT when given NULL or ERR_PTR Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20jfs_lookup(): don't bother with . or ..Al Viro
they'll never be passed to ->lookup() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20get rid of useless dget_parent() in btrfs rename() and link()Al Viro
->d_parent is locked and stable there... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20get rid of useless dget_parent() in fs/btrfs/ioctl.cAl Viro
both callers there have dentry->d_parent stabilized by the fact that their caller had obtained dentry from lookup_one_len() and had not dropped ->i_mutex on parent since then. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlersJosef Bacik
Btrfs needs to be able to control how filemap_write_and_wait_range() is called in fsync to make it less of a painful operation, so push down taking i_mutex and the calling of filemap_write_and_wait() down into the ->fsync() handlers. Some file systems can drop taking the i_mutex altogether it seems, like ext3 and ocfs2. For correctness sake I just pushed everything down in all cases to make sure that we keep the current behavior the same for everybody, and then each individual fs maintainer can make up their mind about what to do from there. Thanks, Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseekJosef Bacik
This converts everybody to handle SEEK_HOLE/SEEK_DATA properly. In some cases we just return -EINVAL, in others we do the normal generic thing, and in others we're simply making sure that the properly due-dilligence is done. For example in NFS/CIFS we need to make sure the file size is update properly for the SEEK_HOLE and SEEK_DATA case, but since it calls the generic llseek stuff itself that is all we have to do. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20Ext4: handle SEEK_HOLE/SEEK_DATA genericallyJosef Bacik
Since Ext4 has its own lseek we need to make sure it handles SEEK_HOLE/SEEK_DATA. For now just do the same thing that is done in the generic case, somebody else can come along and make it do fancy things later. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20Btrfs: implement our own ->llseekJosef Bacik
In order to handle SEEK_HOLE/SEEK_DATA we need to implement our own llseek. Basically for the normal SEEK_*'s we will just defer to the generic helper, and for SEEK_HOLE/SEEK_DATA we will use our fiemap helper to figure out the nearest hole or data. Currently this helper doesn't check for delalloc bytes for prealloc space, so for now treat prealloc as data until that is fixed. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: add SEEK_HOLE and SEEK_DATA flagsJosef Bacik
This just gets us ready to support the SEEK_HOLE and SEEK_DATA flags. Turns out using fiemap in things like cp cause more problems than it solves, so lets try and give userspace an interface that doesn't suck. We need to match solaris here, and the definitions are *o* If /whence/ is SEEK_HOLE, the offset of the start of the next hole greater than or equal to the supplied offset is returned. The definition of a hole is provided near the end of the DESCRIPTION. *o* If /whence/ is SEEK_DATA, the file pointer is set to the start of the next non-hole file region greater than or equal to the supplied offset. So in the generic case the entire file is data and there is a virtual hole at the end. That means we will just return i_size for SEEK_HOLE and will return the same offset for SEEK_DATA. This is how Solaris does it so we have to do it the same way. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20reiserfs: make reiserfs default to barrier=flushChristoph Hellwig
Change the default reiserfs mount option to barrier=flush. Based on a patch from Jeff Mahoney in the SuSE tree. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20ext3: make ext3 mount default to barrier=1Christoph Hellwig
This patch turns on barriers by default for ext3. mount -o barrier=0 will turn them off. Based on a patch from Chris Mason in the SuSE tree. Signed-off-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Eric Sandeen <sandeen@redhat.com> Acked-by: Jan Kara <jack@suse.cz> Acked-by: Jeff Mahoney <jeffm@suse.com> Acked-by: Ted Ts'o <tytso@mit.edu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20don't open-code parent_ino() in assorted ->readdir()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20minix_getattr(): don't bother with ->d_parentAl Viro
we can find superblock easier, TYVM... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20coda_venus_readdir(): use offsetof()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: seq_file - add event counter to simplify poll() supportKay Sievers
Moving the event counter into the dynamically allocated 'struc seq_file' allows poll() support without the need to allocate its own tracking structure. All current users are switched over to use the new counter. Requested-by: Andrew Morton akpm@linux-foundation.org Acked-by: NeilBrown <neilb@suse.de> Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: move inode_dio_done to the end_io handlerChristoph Hellwig
For filesystems that delay their end_io processing we should keep our i_dio_count until the the processing is done. Enable this by moving the inode_dio_done call to the end_io handler if one exist. Note that the actual move to the workqueue for ext4 and XFS is not done in this patch yet, but left to the filesystem maintainers. At least for XFS it's not needed yet either as XFS has an internal equivalent to i_dio_count. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: simplify the blockdev_direct_IO prototypeChristoph Hellwig
Simple filesystems always pass inode->i_sb_bdev as the block device argument, and never need a end_io handler. Let's simply things for them and for my grepping activity by dropping these arguments. The only thing not falling into that scheme is ext4, which passes and end_io handler without needing special flags (yet), but given how messy the direct I/O code there is use of __blockdev_direct_IO in one instead of two out of three cases isn't going to make a large difference anyway. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: always maintain i_dio_countChristoph Hellwig
Maintain i_dio_count for all filesystems, not just those using DIO_LOCKING. This these filesystems to also protect truncate against direct I/O requests by using common code. Right now the only non-DIO_LOCKING filesystem that appears to do so is XFS, which uses an opencoded variant of the i_dio_count scheme. Behaviour doesn't change for filesystems never calling inode_dio_wait. For ext4 behaviour changes when using the dioread_nonlock option, which previously was missing any protection between truncate and direct I/O reads. For ocfs2 that handcrafted i_dio_count manipulations are replaced with the common code now enable. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: move inode_dio_wait calls into ->setattrChristoph Hellwig
Let filesystems handle waiting for direct I/O requests themselves instead of doing it beforehand. This means filesystem-specific locks to prevent new dio referenes from appearing can be held. This is important to allow generalizing i_dio_count to non-DIO_LOCKING filesystems. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: kill i_alloc_semChristoph Hellwig
i_alloc_sem is a rather special rw_semaphore. It's the last one that may be released by a non-owner, and it's write side is always mirrored by real exclusion. It's intended use it to wait for all pending direct I/O requests to finish before starting a truncate. Replace it with a hand-grown construct: - exclusion for truncates is already guaranteed by i_mutex, so it can simply fall way - the reader side is replaced by an i_dio_count member in struct inode that counts the number of pending direct I/O requests. Truncate can't proceed as long as it's non-zero - when i_dio_count reaches non-zero we wake up a pending truncate using wake_up_bit on a new bit in i_flags - new references to i_dio_count can't appear while we are waiting for it to read zero because the direct I/O count always needs i_mutex (or an equivalent like XFS's i_iolock) for starting a new operation. This scheme is much simpler, and saves the space of a spinlock_t and a struct list_head in struct inode (typically 160 bits on a non-debug 64-bit system). Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: simplify handling of zero sized reads in __blockdev_direct_IOChristoph Hellwig
Reject zero sized reads as soon as we know our I/O length, and don't borther with locks or allocations that might have to be cleaned up otherwise. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20ext4: Rewrite ext4_page_mkwrite() to use generic helpersJan Kara
Rewrite ext4_page_mkwrite() to use __block_page_mkwrite() helper. This removes the need of using i_alloc_sem to avoid races with truncate which seems to be the wrong locking order according to lock ordering documented in mm/rmap.c. Also calling ext4_da_write_begin() as used by the old code seems to be problematic because we can decide to flush delay-allocated blocks which will acquire s_umount semaphore - again creating unpleasant lock dependency if not directly a deadlock. Also add a check for frozen filesystem so that we don't busyloop in page fault when the filesystem is frozen. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fat: remove i_alloc_sem abuseChristoph Hellwig
Add a new rw_semaphore to protect bmap against truncate. Previous i_alloc_sem was abused for this, but it's going away in this series. Note that we can't simply use i_mutex, given that the swapon code calls ->bmap under it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>