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2010-01-19ecryptfs: fix interpose/interpolate typos in commentsErez Zadok
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu> Acked-by: Dustin Kirkland <kirkland@canonical.com> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2010-01-19ecryptfs: pass matching flags to interpose as defined and used thereErez Zadok
ecryptfs_interpose checks if one of the flags passed is ECRYPTFS_INTERPOSE_FLAG_D_ADD, defined as 0x00000001 in ecryptfs_kernel.h. But the only user of ecryptfs_interpose to pass a non-zero flag to it, has hard-coded the value as "1". This could spell trouble if any of these values changes in the future. Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu> Cc: Dustin Kirkland <kirkland@canonical.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2010-01-19ecryptfs: remove unnecessary d_drop calls in ecryptfs_linkErez Zadok
Unnecessary because it would unhash perfectly valid dentries, causing them to have to be re-looked up the next time they're needed, which presumably is right after. Signed-off-by: Aseem Rastogi <arastogi@cs.sunysb.edu> Signed-off-by: Shrikar archak <shrikar84@gmail.com> Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu> Cc: Saumitra Bhanage <sbhanage@cs.sunysb.edu> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2010-01-19ecryptfs: don't ignore return value from lock_renameErez Zadok
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu> Cc: Dustin Kirkland <kirkland@canonical.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2010-01-19ecryptfs: initialize private persistent file before dereferencing pointerErez Zadok
Ecryptfs_open dereferences a pointer to the private lower file (the one stored in the ecryptfs inode), without checking if the pointer is NULL. Right afterward, it initializes that pointer if it is NULL. Swap order of statements to first initialize. Bug discovered by Duckjin Kang. Signed-off-by: Duckjin Kang <fromdj2k@gmail.com> Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu> Cc: Dustin Kirkland <kirkland@canonical.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2010-01-19eCryptfs: Remove mmap from directory operationsTyler Hicks
Adrian reported that mkfontscale didn't work inside of eCryptfs mounts. Strace revealed the following: open("./", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY|O_CLOEXEC) = 3 fcntl64(3, F_GETFD) = 0x1 (flags FD_CLOEXEC) open("./fonts.scale", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 4 getdents(3, /* 80 entries */, 32768) = 2304 open("./.", O_RDONLY) = 5 fcntl64(5, F_SETFD, FD_CLOEXEC) = 0 fstat64(5, {st_mode=S_IFDIR|0755, st_size=16384, ...}) = 0 mmap2(NULL, 16384, PROT_READ, MAP_PRIVATE, 5, 0) = 0xb7fcf000 close(5) = 0 --- SIGBUS (Bus error) @ 0 (0) --- +++ killed by SIGBUS +++ The mmap2() on a directory was successful, resulting in a SIGBUS signal later. This patch removes mmap() from the list of possible ecryptfs_dir_fops so that mmap() isn't possible on eCryptfs directory files. https://bugs.launchpad.net/ecryptfs/+bug/400443 Reported-by: Adrian C. <anrxc@sysphere.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2010-01-19eCryptfs: Add getattr functionTyler Hicks
The i_blocks field of an eCryptfs inode cannot be trusted, but generic_fillattr() uses it to instantiate the blocks field of a stat() syscall when a filesystem doesn't implement its own getattr(). Users have noticed that the output of du is incorrect on newly created files. This patch creates ecryptfs_getattr() which calls into the lower filesystem's getattr() so that eCryptfs can use its kstat.blocks value after calling generic_fillattr(). It is important to note that the block count includes the eCryptfs metadata stored in the beginning of the lower file plus any padding used to fill an extent before encryption. https://bugs.launchpad.net/ecryptfs/+bug/390833 Reported-by: Dominic Sacré <dominic.sacre@gmx.de> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2010-01-19eCryptfs: Use notify_change for truncating lower inodesTyler Hicks
When truncating inodes in the lower filesystem, eCryptfs directly invoked vmtruncate(). As Christoph Hellwig pointed out, vmtruncate() is a filesystem helper function, but filesystems may need to do more than just a call to vmtruncate(). This patch moves the lower inode truncation out of ecryptfs_truncate() and renames the function to truncate_upper(). truncate_upper() updates an iattr for the lower inode to indicate if the lower inode needs to be truncated upon return. ecryptfs_setattr() then calls notify_change(), using the updated iattr for the lower inode, to complete the truncation. For eCryptfs functions needing to truncate, ecryptfs_truncate() is reintroduced as a simple way to truncate the upper inode to a specified size and then truncate the lower inode accordingly. https://bugs.launchpad.net/bugs/451368 Reported-by: Christoph Hellwig <hch@lst.de> Acked-by: Dustin Kirkland <kirkland@canonical.com> Cc: ecryptfs-devel@lists.launchpad.net Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2010-01-20xfs: rearrange xfs_mod_sb() to avoid array subscript warningDave Chinner
gcc warns of an array subscript out of bounds in xfs_mod_sb(). The code is written in such a way that if the array subscript is out of bounds, then it will assert fail. Rearrange the code to avoid the bounds check warning. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-20xfs: suppress spurious uninitialised var warning in xfs_bmapi()Dave Chinner
Initialise the xfs_bmalloca_t structure to zero to avoid uninitialised variable warnings. This is done by zeroing the arg structure rather than using the uninitialised_var() trick so we know for certain that the structure is correctly initialised as xfs_bmapi is a very complex function and it is difficult to prove warnings are spurious. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-20xfs: make compile warn about char sign mismatches againDave Chinner
The -fno-unsigned-char directive has no effect anymore as the XFs build is clean. However, the kernel build hides pointer sign differences so turn that back on so that we can clean up all the mismatches prior to a userspace code resync. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-20xfs: clean up sign warnings in dir2 codeDave Chinner
We are now consistently using unsigned char strings for names so fix up the remaining warnings in the dir2 code to complete the cleanup. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-20xfs: convert attr to use unsigned namesDave Chinner
To be consistent with the directory code, the attr code should use unsigned names. Convert the names from the vfs at the highest level to unsigned, and ænsure they are consistenly used as unsigned down to disk. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-20xfs: xfs_buf_iomove() doesn't care about signednessDave Chinner
xfs_buf_iomove() uses xfs_caddr_t as it's parameter types, but it doesn't care about the signedness of the variables as it is just copying the data. Change the prototype to use void * so that we don't get sign warnings at call sites. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-20xfs: make xfs_dir_cilookup_result use unsigned charDave Chinner
For consistency with the result of the code. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-20xfs: convert dirnameops to unsigned char namesDave Chinner
To be consistent across the codebase, convert the dirnameops to pass the directory names by unsigned char strings. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-20xfs: convert DM ops to use unsigned char namesDave Chinner
dmops uses a signed char for it's namespace event. To be consistent with the rest of the code, convert them to unsigned char for the namespace string. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-20xfs: directory names are unsignedDave Chinner
Convert the struct xfs_name to use unsigned chars for the name strings to match both what is stored on disk (__uint8_t) and what the VFS expects (unsigned char). Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-01-19fs/bio.c: fix shadows sparse warningThiago Farina
fs/bio.c:81:33: warning: symbol 'bslab' shadows an earlier one fs/bio.c:74:25: originally declared here Signed-off-by: Thiago Farina <tfransosi@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-01-18Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds
* 'for-linus' of git://oss.sgi.com/xfs/xfs: xfs: xfs_swap_extents needs to handle dynamic fork offsets xfs: fix missing error check in xfs_rtfree_range xfs: fix stale inode flush avoidance xfs: Remove inode iolock held check during allocation xfs: reclaim all inodes by background tree walks xfs: Avoid inodes in reclaim when flushing from inode cache xfs: reclaim inodes under a write lock
2010-01-17Btrfs: fix possible panic on unmountJosef Bacik
We can race with the unmount of an fs and the stopping of a kthread where we will free the block group before we're done using it. The reason for this is because we do not hold a reference on the block group while its caching, since the allocator drops its reference once it exits or moves on to the next block group. This patch fixes the problem by taking a reference to the block group before we start caching and dropping it when we're done to make sure all accesses to the block group are safe. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-17Btrfs: deal with NULL acl sent to btrfs_set_aclChris Mason
It is legal for btrfs_set_acl to be sent a NULL acl. This makes sure we don't dereference it. A similar patch was sent by Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-17Btrfs: fix regression in orphan cleanupJosef Bacik
Currently orphan cleanup only ever gets triggered if we cross subvolumes during a lookup, which means that if we just mount a plain jane fs that has orphans in it, they will never get cleaned up. This results in panic's like these http://www.kerneloops.org/oops.php?number=1109085 where adding an orphan entry results in -EEXIST being returned and we panic. In order to fix this, we check to see on lookup if our root has had the orphan cleanup done, and if not go ahead and do it. This is easily reproduceable by running this testcase #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <string.h> #include <unistd.h> #include <stdio.h> int main(int argc, char **argv) { char data[4096]; char newdata[4096]; int fd1, fd2; memset(data, 'a', 4096); memset(newdata, 'b', 4096); while (1) { int i; fd1 = creat("file1", 0666); if (fd1 < 0) break; for (i = 0; i < 512; i++) write(fd1, data, 4096); fsync(fd1); close(fd1); fd2 = creat("file2", 0666); if (fd2 < 0) break; ftruncate(fd2, 4096 * 512); for (i = 0; i < 512; i++) write(fd2, newdata, 4096); close(fd2); i = rename("file2", "file1"); unlink("file1"); } return 0; } and then pulling the power on the box, and then trying to run that test again when the box comes back up. I've tested this locally and it fixes the problem. Thanks to Tomas Carnecky for helping me track this down initially. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-17Btrfs: Fix race in btrfs_mark_extent_writtenYan, Zheng
Fix bug reported by Johannes Hirte. The reason of that bug is btrfs_del_items is called after btrfs_duplicate_item and btrfs_del_items triggers tree balance. The fix is check that case and call btrfs_search_slot when needed. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-17Btrfs, fix memory leaks in error pathsJiri Slaby
Stanse found 2 memory leaks in relocate_block_group and __btrfs_map_block. cluster and multi are not freed/assigned on all paths. Fix that. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: linux-btrfs@vger.kernel.org Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-17Btrfs: align offsets for btrfs_ordered_update_i_sizeYan, Zheng
Some callers of btrfs_ordered_update_i_size can now pass in a NULL for the ordered extent to update against. This makes sure we properly align the offset they pass in when deciding how much to bump the on disk i_size. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-17btrfs: fix missing last-entry in readdir(3)Jan Engelhardt
parent 49313cdac7b34c9f7ecbb1780cfc648b1c082cd7 (v2.6.32-1-g49313cd) commit ff48c08e1c05c67e8348ab6f8a24de8034e0e34d Author: Jan Engelhardt <jengelh@medozas.de> Date: Wed Dec 9 22:57:36 2009 +0100 Btrfs: fix missing last-entry in readdir(3) When one does a 32-bit readdir(3), the last entry of a directory is missing. This is however not due to passing a large value to filldir, but it seems to have to do with glibc doing telldir or something quirky. In any case, this patch fixes it in practice. Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-17Merge 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: do_add_mount() should sanitize mnt_flags CIFS shouldn't make mountpoints shrinkable mnt_flags fixes in do_remount() attach_recursive_mnt() needs to hold vfsmount_lock over set_mnt_shared() may_umount() needs namespace_sem Fix configfs leak Fix the -ESTALE handling in do_filp_open() ecryptfs: Fix refcnt leak on ecryptfs_follow_link() error path Fix ACC_MODE() for real Unrot uml mconsole a bit hppfs: handle ->put_link() Kill 9p readlink() fix autofs/afs/etc. magic mountpoint breakage
2010-01-16nommu: fix shared mmap after truncate shrinkage problemsDavid Howells
Fix a problem in NOMMU mmap with ramfs whereby a shared mmap can happen over the end of a truncation. The problem is that ramfs_nommu_check_mappings() checks that the reduced file size against the VMA tree, but not the vm_region tree. The following sequence of events can cause the problem: fd = open("/tmp/x", O_RDWR|O_TRUNC|O_CREAT, 0600); ftruncate(fd, 32 * 1024); a = mmap(NULL, 32 * 1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); b = mmap(NULL, 16 * 1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); munmap(a, 32 * 1024); ftruncate(fd, 16 * 1024); c = mmap(NULL, 32 * 1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); Mapping 'a' creates a vm_region covering 32KB of the file. Mapping 'b' sees that the vm_region from 'a' is covering the region it wants and so shares it, pinning it in memory. Mapping 'a' then goes away and the file is truncated to the end of VMA 'b'. However, the region allocated by 'a' is still in effect, and has _not_ been reduced. Mapping 'c' is then created, and because there's a vm_region covering the desired region, get_unmapped_area() is _not_ called to repeat the check, and the mapping is granted, even though the pages from the latter half of the mapping have been discarded. However: d = mmap(NULL, 16 * 1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); Mapping 'd' should work, and should end up sharing the region allocated by 'a'. To deal with this, we shrink the vm_region struct during the truncation, lest do_mmap_pgoff() take it as licence to share the full region automatically without calling the get_unmapped_area() file op again. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16nommu: fix race between ramfs truncation and shared mmapDavid Howells
Fix the race between the truncation of a ramfs file and an attempt to make a shared mmap of region of that file. The problem is that do_mmap_pgoff() calls f_op->get_unmapped_area() to verify that the file region is made of contiguous pages and to find its base address - but there isn't any locking to guarantee this region until vma_prio_tree_insert() is called by add_vma_to_mm(). Note that moving the functionality into f_op->mmap() doesn't help as that is also called before vma_prio_tree_insert(). Instead make ramfs_nommu_check_mappings() grab nommu_region_sem whilst it does its checks. This means that this function will wait whilst mmaps take place. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16do_add_mount() should sanitize mnt_flagsAl Viro
MNT_WRITE_HOLD shouldn't leak into new vfsmount and neither should MNT_SHARED (the latter will be set properly, along with the rest of shared-subtree data structures) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-01-16CIFS shouldn't make mountpoints shrinkableAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-01-16mnt_flags fixes in do_remount()Al Viro
* need vfsmount_lock over modifying it * need to preserve MNT_SHARED/MNT_UNBINDABLE Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-01-16attach_recursive_mnt() needs to hold vfsmount_lock over set_mnt_shared()Al Viro
race in mnt_flags update Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-01-16may_umount() needs namespace_semAl Viro
otherwise it races with clone_mnt() changing mnt_share/mnt_slaves Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-01-15inotify: only warn once for inotify problemsEric Paris
inotify will WARN() if it finds that the idr and the fsnotify internals somehow got out of sync. It was only supposed to do this once but due to this stupid bug it would warn every single time a problem was detected. Signed-off-by: Eric Paris <eparis@redhat.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-15inotify: do not reuse watch descriptorsEric Paris
Since commit 7e790dd5fc937bc8d2400c30a05e32a9e9eef276 ("inotify: fix error paths in inotify_update_watch") inotify changed the manor in which it gave watch descriptors back to userspace. Previous to this commit inotify acted like the following: inotify_add_watch(X, Y, Z) = 1 inotify_rm_watch(X, 1); inotify_add_watch(X, Y, Z) = 2 but after this patch inotify would return watch descriptors like so: inotify_add_watch(X, Y, Z) = 1 inotify_rm_watch(X, 1); inotify_add_watch(X, Y, Z) = 1 which I saw as equivalent to opening an fd where open(file) = 1; close(1); open(file) = 1; seemed perfectly reasonable. The issue is that quite a bit of userspace apparently relies on the behavior in which watch descriptors will not be quickly reused. KDE relies on it, I know some selinux packages rely on it, and I have heard complaints from other random sources such as debian bug 558981. Although the man page implies what we do is ok, we broke userspace so this patch almost reverts us to the old behavior. It is still slightly racey and I have patches that would fix that, but they are rather large and this will fix it for all real world cases. The race is as follows: - task1 creates a watch and blocks in idr_new_watch() before it updates the hint. - task2 creates a watch and updates the hint. - task1 updates the hint with it's older wd - task removes the watch created by task2 - task adds a new watch and will reuse the wd originally given to task2 it requires moving some locking around the hint (last_wd) but this should solve it for the real world and be -stable safe. As a side effect this patch papers over a bug in the lib/idr code which is causing a large number WARN's to pop on people's system and many reports in kerneloops.org. I'm working on the root cause of that idr bug seperately but this should make inotify immune to that issue. Signed-off-by: Eric Paris <eparis@redhat.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-15xfs: move more buffer helpers into xfs_buf.cChristoph Hellwig
Move xfsbdstrat and xfs_bdstrat_cb from xfs_lrw.c and xfs_bioerror and xfs_bioerror_relse from xfs_rw.c into xfs_buf.c. This also means xfs_bioerror and xfs_bioerror_relse can be marked static now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-15xfs: clean up xfs_bwriteChristoph Hellwig
Fold XFS_bwrite into it's only caller, xfs_bwrite and move it into xfs_buf.c instead of leaving it as a fairly large inline function. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-15xfs: clean up log buffer writesChristoph Hellwig
Don't bother using XFS_bwrite as it doesn't provide much code for our use case. Instead opencode it and fold xlog_bdstrat_cb into the new xlog_bdstrat helper. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-15xfs: embed the pagb_list array in the perag structureDave Chinner
Now that the perag structure is allocated memory rather than held in an array, we don't need to have the busy extent array external to the structure. Embed it into the perag structure to avoid needing an extra allocation when setting up. 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: handle ENOMEM correctly during initialisation of perag structuresDave Chinner
Add proper error handling in case an error occurs while initializing new perag structures for a mount point. The mount structure is restored to its previous state by deleting and freeing any perag structures added during the call. 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: Kill filestreams cache flushDave Chinner
The filestreams cache flush is not needed in the sync code as it does not affect data writeback, and it is now not used by the growfs code, either, so kill it. 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: Add trace points for per-ag refcount debugging.Dave Chinner
Uninline xfs_perag_{get,put} so that tracepoints can be inserted into them to speed debugging of reference count problems. 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: Reference count per-ag structuresDave Chinner
Reference count the per-ag structures to ensure that we keep get/put pairs balanced. Assert that the reference counts are zero at unmount time to catch leaks. In future, reference counts will enable us to safely remove perag structures by allowing us to detect when they are no longer in use. 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: 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>
2010-01-15xfs: Convert filestreams code to use per-ag get/put routinesDave Chinner
Use xfs_perag_get() and xfs_perag_put() in the filestreams code. 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: Don't directly reference m_perag in allocation codeDave Chinner
Start abstracting the perag references so that the indexing of the structures is not directly coded into all the places that uses the perag structures. This will allow us to separate the use of the perag structure and the way it is indexed and hence avoid the known deadlocks related to growing a busy filesystem. 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: rename xfs_get_peragDave Chinner
xfs_get_perag is really getting the perag that an inode belongs to based on it's inode number. Convert the use of this function to just get the perag from a provided ag number. Use this new function to obtain the per-ag structure when traversing the per AG inode trees for sync and reclaim. Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>