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* writeback: pass in super_block to bdi_start_writeback()Jens Axboe2009-09-261-2/+4
| | | | | | | | | | | Sometimes we only want to write pages from a specific super_block, so allow that to be passed in. This fixes a problem with commit 56a131dcf7ed36c3c6e36bea448b674ea85ed5bb causing writeback on all super_blocks on a bdi, where we only really want to sync a specific sb from writeback_inodes_sb(). Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Merge branch 'writeback' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2009-09-252-53/+118
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'writeback' of git://git.kernel.dk/linux-2.6-block: writeback: writeback_inodes_sb() should use bdi_start_writeback() writeback: don't delay inodes redirtied by a fast dirtier writeback: make the super_block pinning more efficient writeback: don't resort for a single super_block in move_expired_inodes() writeback: move inodes from one super_block together writeback: get rid to incorrect references to pdflush in comments writeback: improve readability of the wb_writeback() continue/break logic writeback: cleanup writeback_single_inode() writeback: kupdate writeback shall not stop when more io is possible writeback: stop background writeback when below background threshold writeback: balance_dirty_pages() shall write more than dirtied pages fs: Fix busyloop in wb_writeback()
| * writeback: writeback_inodes_sb() should use bdi_start_writeback()Jens Axboe2009-09-251-1/+1
| | | | | | | | | | | | | | Pointless to iterate other devices looking for a super, when we have a bdi mapping. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * writeback: don't delay inodes redirtied by a fast dirtierWu Fengguang2009-09-251-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Debug traces show that in per-bdi writeback, the inode under writeback almost always get redirtied by a busy dirtier. We used to call redirty_tail() in this case, which could delay inode for up to 30s. This is unacceptable because it now happens so frequently for plain cp/dd, that the accumulated delays could make writeback of big files very slow. So let's distinguish between data redirty and metadata only redirty. The first one is caused by a busy dirtier, while the latter one could happen in XFS, NFS, etc. when they are doing delalloc or updating isize. The inode being busy dirtied will now be requeued for next io, while the inode being redirtied by fs will continue to be delayed to avoid repeated IO. CC: Jan Kara <jack@suse.cz> CC: Theodore Ts'o <tytso@mit.edu> CC: Dave Chinner <david@fromorbit.com> CC: Chris Mason <chris.mason@oracle.com> CC: Christoph Hellwig <hch@infradead.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * writeback: make the super_block pinning more efficientJens Axboe2009-09-251-17/+29
| | | | | | | | | | | | | | | | | | | | Currently we pin the inode->i_sb for every single inode. This increases cache traffic on sb->s_umount sem. Lets instead cache the inode sb pin state and keep the super_block pinned for as long as keep writing out inodes from the same super_block. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * writeback: don't resort for a single super_block in move_expired_inodes()Jens Axboe2009-09-251-1/+11
| | | | | | | | | | | | | | If we only moved inodes from a single super_block to the temporary list, there's no point in doing a resort for multiple super_blocks. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * writeback: move inodes from one super_block togetherShaohua Li2009-09-251-3/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __mark_inode_dirty adds inode to wb dirty list in random order. If a disk has several partitions, writeback might keep spindle moving between partitions. To reduce the move, better write big chunk of one partition and then move to another. Inodes from one fs usually are in one partion, so idealy move indoes from one fs together should reduce spindle move. This patch tries to address this. Before per-bdi writeback is added, the behavior is write indoes from one fs first and then another, so the patch restores previous behavior. The loop in the patch is a bit ugly, should we add a dirty list for each superblock in bdi_writeback? Test in a two partition disk with attached fio script shows about 3% ~ 6% improvement. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * writeback: get rid to incorrect references to pdflush in commentsJens Axboe2009-09-252-9/+6
| | | | | | | | Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * writeback: improve readability of the wb_writeback() continue/break logicJens Axboe2009-09-251-20/+23
| | | | | | | | | | | | | | And throw some comments in there, too. Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * writeback: cleanup writeback_single_inode()Wu Fengguang2009-09-251-8/+7
| | | | | | | | | | | | | | | | | | | | | | Make the if-else straight in writeback_single_inode(). No behavior change. Cc: Jan Kara <jack@suse.cz> Cc: Michael Rubin <mrubin@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * writeback: kupdate writeback shall not stop when more io is possibleWu Fengguang2009-09-251-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the kupdate case, which disregards wbc.more_io and stop writeback prematurely even when there are more inodes to be synced. wbc.more_io should always be respected. Also remove the pages_skipped check. It will set when some page(s) of some inode(s) cannot be written for now. Such inodes will be delayed for a while. This variable has nothing to do with whether there are other writeable inodes. CC: Jan Kara <jack@suse.cz> CC: Dave Chinner <david@fromorbit.com> CC: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * writeback: stop background writeback when below background thresholdWu Fengguang2009-09-251-11/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Treat bdi_start_writeback(0) as a special request to do background write, and stop such work when we are below the background dirty threshold. Also simplify the (nr_pages <= 0) checks. Since we already pass in nr_pages=LONG_MAX for WB_SYNC_ALL and background writes, we don't need to worry about it being decreased to zero. Reported-by: Richard Kennedy <richard@rsk.demon.co.uk> CC: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * fs: Fix busyloop in wb_writeback()Jan Kara2009-09-251-1/+18
| | | | | | | | | | | | | | | | | | | | | | | | If all inodes are under writeback (e.g. in case when there's only one inode with dirty pages), wb_writeback() with WB_SYNC_NONE work basically degrades to busylooping until I_SYNC flags of the inode is cleared. Fix the problem by waiting on I_SYNC flags of an inode on b_more_io list in case we failed to write anything. Tested-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | procfs: disable per-task stack usage on NOMMUAndrew Morton2009-09-241-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | It needs walk_page_range(). Reported-by: Michal Simek <monstr@monstr.eu> Tested-by: Michal Simek <monstr@monstr.eu> Cc: Stefani Seibold <stefani@seibold.net> Cc: David Howells <dhowells@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-linus' of ↵Linus Torvalds2009-09-249-72/+77
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6: eCryptfs: Prevent lower dentry from going negative during unlink eCryptfs: Propagate vfs_read and vfs_write return codes eCryptfs: Validate global auth tok keys eCryptfs: Filename encryption only supports password auth tokens eCryptfs: Check for O_RDONLY lower inodes when opening lower files eCryptfs: Handle unrecognized tag 3 cipher codes ecryptfs: improved dependency checking and reporting eCryptfs: Fix lockdep-reported AB-BA mutex issue ecryptfs: Remove unneeded locking that triggers lockdep false positives
| * | eCryptfs: Prevent lower dentry from going negative during unlinkTyler Hicks2009-09-231-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When calling vfs_unlink() on the lower dentry, d_delete() turns the dentry into a negative dentry when the d_count is 1. This eventually caused a NULL pointer deref when a read() or write() was done and the negative dentry's d_inode was dereferenced in ecryptfs_read_update_atime() or ecryptfs_getxattr(). Placing mutt's tmpdir in an eCryptfs mount is what initially triggered the oops and I was able to reproduce it with the following sequence: open("/tmp/upper/foo", O_RDWR|O_CREAT|O_EXCL|O_NOFOLLOW, 0600) = 3 link("/tmp/upper/foo", "/tmp/upper/bar") = 0 unlink("/tmp/upper/foo") = 0 open("/tmp/upper/bar", O_RDWR|O_CREAT|O_NOFOLLOW, 0600) = 4 unlink("/tmp/upper/bar") = 0 write(4, "eCryptfs test\n"..., 14 <unfinished ...> +++ killed by SIGKILL +++ https://bugs.launchpad.net/ecryptfs/+bug/387073 Reported-by: Loïc Minier <loic.minier@canonical.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: ecryptfs-devel@lists.launchpad.net Cc: stable <stable@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
| * | eCryptfs: Propagate vfs_read and vfs_write return codesTyler Hicks2009-09-233-29/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Errors returned from vfs_read() and vfs_write() calls to the lower filesystem were being masked as -EINVAL. This caused some confusion to users who saw EINVAL instead of ENOSPC when the disk was full, for instance. Also, the actual bytes read or written were not accessible by callers to ecryptfs_read_lower() and ecryptfs_write_lower(), which may be useful in some cases. This patch updates the error handling logic where those functions are called in order to accept positive return codes indicating success. Cc: Eric Sandeen <esandeen@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: ecryptfs-devel@lists.launchpad.net Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
| * | eCryptfs: Validate global auth tok keysTyler Hicks2009-09-231-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When searching through the global authentication tokens for a given key signature, verify that a matching key has not been revoked and has not expired. This allows the `keyctl revoke` command to be properly used on keys in use by eCryptfs. Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: ecryptfs-devel@lists.launchpad.net Cc: stable <stable@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
| * | eCryptfs: Filename encryption only supports password auth tokensTyler Hicks2009-09-232-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Returns -ENOTSUPP when attempting to use filename encryption with something other than a password authentication token, such as a private token from openssl. Using filename encryption with a userspace eCryptfs key module is a future goal. Until then, this patch handles the situation a little better than simply using a BUG_ON(). Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: ecryptfs-devel@lists.launchpad.net Cc: stable <stable@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
| * | eCryptfs: Check for O_RDONLY lower inodes when opening lower filesTyler Hicks2009-09-232-18/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the lower inode is read-only, don't attempt to open the lower file read/write and don't hand off the open request to the privileged eCryptfs kthread for opening it read/write. Instead, only try an unprivileged, read-only open of the file and give up if that fails. This patch fixes an oops when eCryptfs is mounted on top of a read-only mount. Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Eric Sandeen <esandeen@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: ecryptfs-devel@lists.launchpad.net Cc: stable <stable@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
| * | eCryptfs: Handle unrecognized tag 3 cipher codesTyler Hicks2009-09-232-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Returns an error when an unrecognized cipher code is present in a tag 3 packet or an ecryptfs_crypt_stat cannot be initialized. Also sets an crypt_stat->tfm error pointer to NULL to ensure that it will not be incorrectly freed in ecryptfs_destroy_crypt_stat(). Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: ecryptfs-devel@lists.launchpad.net Cc: stable <stable@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
| * | ecryptfs: improved dependency checking and reportingDave Hansen2009-09-232-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So, I compiled a 2.6.31-rc5 kernel with ecryptfs and loaded its module. When it came time to mount my filesystem, I got this in dmesg, and it refused to mount: [93577.776637] Unable to allocate crypto cipher with name [aes]; rc = [-2] [93577.783280] Error attempting to initialize key TFM cipher with name = [aes]; rc = [-2] [93577.791183] Error attempting to initialize cipher with name = [aes] and key size = [32]; rc = [-2] [93577.800113] Error parsing options; rc = [-22] I figured from the error message that I'd either forgotten to load "aes" or that my key size was bogus. Neither one of those was the case. In fact, I was missing the CRYPTO_ECB config option and the 'ecb' module. Unfortunately, there's no trace of 'ecb' in that error message. I've done two things to fix this. First, I've modified ecryptfs's Kconfig entry to select CRYPTO_ECB and CRYPTO_CBC. I also took CRYPTO out of the dependencies since the 'select' will take care of it for us. I've also modified the error messages to print a string that should contain both 'ecb' and 'aes' in my error case. That will give any future users a chance of finding the right modules and Kconfig options. I also wonder if we should: select CRYPTO_AES if !EMBEDDED since I think most ecryptfs users are using AES like me. Cc: ecryptfs-devel@lists.launchpad.net Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Dustin Kirkland <kirkland@canonical.com> Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> [tyhicks@linux.vnet.ibm.com: Removed extra newline, 80-char violation] Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
| * | eCryptfs: Fix lockdep-reported AB-BA mutex issueRoland Dreier2009-09-232-10/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lockdep reports the following valid-looking possible AB-BA deadlock with global_auth_tok_list_mutex and keysig_list_mutex: ecryptfs_new_file_context() -> ecryptfs_copy_mount_wide_sigs_to_inode_sigs() -> mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); -> ecryptfs_add_keysig() -> mutex_lock(&crypt_stat->keysig_list_mutex); vs ecryptfs_generate_key_packet_set() -> mutex_lock(&crypt_stat->keysig_list_mutex); -> ecryptfs_find_global_auth_tok_for_sig() -> mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); ie the two mutexes are taken in opposite orders in the two different code paths. I'm not sure if this is a real bug where two threads could actually hit the two paths in parallel and deadlock, but it at least makes lockdep impossible to use with ecryptfs since this report triggers every time and disables future lockdep reporting. Since ecryptfs_add_keysig() is called only from the single callsite in ecryptfs_copy_mount_wide_sigs_to_inode_sigs(), the simplest fix seems to be to move the lock of keysig_list_mutex back up outside of the where global_auth_tok_list_mutex is taken. This patch does that, and fixes the lockdep report on my system (and ecryptfs still works OK). The full output of lockdep fixed by this patch is: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.31-2-generic #14~rbd2 ------------------------------------------------------- gdm/2640 is trying to acquire lock: (&mount_crypt_stat->global_auth_tok_list_mutex){+.+.+.}, at: [<ffffffff8121591e>] ecryptfs_find_global_auth_tok_for_sig+0x2e/0x90 but task is already holding lock: (&crypt_stat->keysig_list_mutex){+.+.+.}, at: [<ffffffff81217728>] ecryptfs_generate_key_packet_set+0x58/0x2b0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&crypt_stat->keysig_list_mutex){+.+.+.}: [<ffffffff8108c897>] check_prev_add+0x2a7/0x370 [<ffffffff8108cfc1>] validate_chain+0x661/0x750 [<ffffffff8108d2e7>] __lock_acquire+0x237/0x430 [<ffffffff8108d585>] lock_acquire+0xa5/0x150 [<ffffffff815526cd>] __mutex_lock_common+0x4d/0x3d0 [<ffffffff81552b56>] mutex_lock_nested+0x46/0x60 [<ffffffff8121526a>] ecryptfs_add_keysig+0x5a/0xb0 [<ffffffff81213299>] ecryptfs_copy_mount_wide_sigs_to_inode_sigs+0x59/0xb0 [<ffffffff81214b06>] ecryptfs_new_file_context+0xa6/0x1a0 [<ffffffff8120e42a>] ecryptfs_initialize_file+0x4a/0x140 [<ffffffff8120e54d>] ecryptfs_create+0x2d/0x60 [<ffffffff8113a7d4>] vfs_create+0xb4/0xe0 [<ffffffff8113a8c4>] __open_namei_create+0xc4/0x110 [<ffffffff8113d1c1>] do_filp_open+0xa01/0xae0 [<ffffffff8112d8d9>] do_sys_open+0x69/0x140 [<ffffffff8112d9f0>] sys_open+0x20/0x30 [<ffffffff81013132>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff -> #0 (&mount_crypt_stat->global_auth_tok_list_mutex){+.+.+.}: [<ffffffff8108c675>] check_prev_add+0x85/0x370 [<ffffffff8108cfc1>] validate_chain+0x661/0x750 [<ffffffff8108d2e7>] __lock_acquire+0x237/0x430 [<ffffffff8108d585>] lock_acquire+0xa5/0x150 [<ffffffff815526cd>] __mutex_lock_common+0x4d/0x3d0 [<ffffffff81552b56>] mutex_lock_nested+0x46/0x60 [<ffffffff8121591e>] ecryptfs_find_global_auth_tok_for_sig+0x2e/0x90 [<ffffffff812177d5>] ecryptfs_generate_key_packet_set+0x105/0x2b0 [<ffffffff81212f49>] ecryptfs_write_headers_virt+0xc9/0x120 [<ffffffff8121306d>] ecryptfs_write_metadata+0xcd/0x200 [<ffffffff8120e44b>] ecryptfs_initialize_file+0x6b/0x140 [<ffffffff8120e54d>] ecryptfs_create+0x2d/0x60 [<ffffffff8113a7d4>] vfs_create+0xb4/0xe0 [<ffffffff8113a8c4>] __open_namei_create+0xc4/0x110 [<ffffffff8113d1c1>] do_filp_open+0xa01/0xae0 [<ffffffff8112d8d9>] do_sys_open+0x69/0x140 [<ffffffff8112d9f0>] sys_open+0x20/0x30 [<ffffffff81013132>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff other info that might help us debug this: 2 locks held by gdm/2640: #0: (&sb->s_type->i_mutex_key#11){+.+.+.}, at: [<ffffffff8113cb8b>] do_filp_open+0x3cb/0xae0 #1: (&crypt_stat->keysig_list_mutex){+.+.+.}, at: [<ffffffff81217728>] ecryptfs_generate_key_packet_set+0x58/0x2b0 stack backtrace: Pid: 2640, comm: gdm Tainted: G C 2.6.31-2-generic #14~rbd2 Call Trace: [<ffffffff8108b988>] print_circular_bug_tail+0xa8/0xf0 [<ffffffff8108c675>] check_prev_add+0x85/0x370 [<ffffffff81094912>] ? __module_text_address+0x12/0x60 [<ffffffff8108cfc1>] validate_chain+0x661/0x750 [<ffffffff81017275>] ? print_context_stack+0x85/0x140 [<ffffffff81089c68>] ? find_usage_backwards+0x38/0x160 [<ffffffff8108d2e7>] __lock_acquire+0x237/0x430 [<ffffffff8108d585>] lock_acquire+0xa5/0x150 [<ffffffff8121591e>] ? ecryptfs_find_global_auth_tok_for_sig+0x2e/0x90 [<ffffffff8108b0b0>] ? check_usage_backwards+0x0/0xb0 [<ffffffff815526cd>] __mutex_lock_common+0x4d/0x3d0 [<ffffffff8121591e>] ? ecryptfs_find_global_auth_tok_for_sig+0x2e/0x90 [<ffffffff8121591e>] ? ecryptfs_find_global_auth_tok_for_sig+0x2e/0x90 [<ffffffff8108c02c>] ? mark_held_locks+0x6c/0xa0 [<ffffffff81125b0d>] ? kmem_cache_alloc+0xfd/0x1a0 [<ffffffff8108c34d>] ? trace_hardirqs_on_caller+0x14d/0x190 [<ffffffff81552b56>] mutex_lock_nested+0x46/0x60 [<ffffffff8121591e>] ecryptfs_find_global_auth_tok_for_sig+0x2e/0x90 [<ffffffff812177d5>] ecryptfs_generate_key_packet_set+0x105/0x2b0 [<ffffffff81212f49>] ecryptfs_write_headers_virt+0xc9/0x120 [<ffffffff8121306d>] ecryptfs_write_metadata+0xcd/0x200 [<ffffffff81210240>] ? ecryptfs_init_persistent_file+0x60/0xe0 [<ffffffff8120e44b>] ecryptfs_initialize_file+0x6b/0x140 [<ffffffff8120e54d>] ecryptfs_create+0x2d/0x60 [<ffffffff8113a7d4>] vfs_create+0xb4/0xe0 [<ffffffff8113a8c4>] __open_namei_create+0xc4/0x110 [<ffffffff8113d1c1>] do_filp_open+0xa01/0xae0 [<ffffffff8129a93e>] ? _raw_spin_unlock+0x5e/0xb0 [<ffffffff8155410b>] ? _spin_unlock+0x2b/0x40 [<ffffffff81139e9b>] ? getname+0x3b/0x240 [<ffffffff81148a5a>] ? alloc_fd+0xfa/0x140 [<ffffffff8112d8d9>] do_sys_open+0x69/0x140 [<ffffffff81553b8f>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff8112d9f0>] sys_open+0x20/0x30 [<ffffffff81013132>] system_call_fastpath+0x16/0x1b Signed-off-by: Roland Dreier <rolandd@cisco.com> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
| * | ecryptfs: Remove unneeded locking that triggers lockdep false positivesRoland Dreier2009-09-232-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In ecryptfs_destroy_inode(), inode_info->lower_file_mutex is locked, and just after the mutex is unlocked, the code does: kmem_cache_free(ecryptfs_inode_info_cache, inode_info); This means that if another context could possibly try to take the same mutex as ecryptfs_destroy_inode(), then it could end up getting the mutex just before the data structure containing the mutex is freed. So any such use would be an obvious use-after-free bug (catchable with slab poisoning or mutex debugging), and therefore the locking in ecryptfs_destroy_inode() is not needed and can be dropped. Similarly, in ecryptfs_destroy_crypt_stat(), crypt_stat->keysig_list_mutex is locked, and then the mutex is unlocked just before the code does: memset(crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat)); Therefore taking this mutex is similarly not necessary. Removing this locking fixes false-positive lockdep reports such as the following (and they are false-positives for exactly the same reason that the locking is not needed): ================================= [ INFO: inconsistent lock state ] 2.6.31-2-generic #14~rbd3 --------------------------------- inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage. kswapd0/323 [HC0[0]:SC0[0]:HE1:SE1] takes: (&inode_info->lower_file_mutex){+.+.?.}, at: [<ffffffff81210d34>] ecryptfs_destroy_inode+0x34/0x100 {RECLAIM_FS-ON-W} state was registered at: [<ffffffff8108c02c>] mark_held_locks+0x6c/0xa0 [<ffffffff8108c10f>] lockdep_trace_alloc+0xaf/0xe0 [<ffffffff81125a51>] kmem_cache_alloc+0x41/0x1a0 [<ffffffff8113117a>] get_empty_filp+0x7a/0x1a0 [<ffffffff8112dd46>] dentry_open+0x36/0xc0 [<ffffffff8121a36c>] ecryptfs_privileged_open+0x5c/0x2e0 [<ffffffff81210283>] ecryptfs_init_persistent_file+0xa3/0xe0 [<ffffffff8120e838>] ecryptfs_lookup_and_interpose_lower+0x278/0x380 [<ffffffff8120f97a>] ecryptfs_lookup+0x12a/0x250 [<ffffffff8113930a>] real_lookup+0xea/0x160 [<ffffffff8113afc8>] do_lookup+0xb8/0xf0 [<ffffffff8113b518>] __link_path_walk+0x518/0x870 [<ffffffff8113bd9c>] path_walk+0x5c/0xc0 [<ffffffff8113be5b>] do_path_lookup+0x5b/0xa0 [<ffffffff8113bfe7>] user_path_at+0x57/0xa0 [<ffffffff811340dc>] vfs_fstatat+0x3c/0x80 [<ffffffff8113424b>] vfs_stat+0x1b/0x20 [<ffffffff81134274>] sys_newstat+0x24/0x50 [<ffffffff81013132>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff irq event stamp: 7811 hardirqs last enabled at (7811): [<ffffffff810c037f>] call_rcu+0x5f/0x90 hardirqs last disabled at (7810): [<ffffffff810c0353>] call_rcu+0x33/0x90 softirqs last enabled at (3764): [<ffffffff810631da>] __do_softirq+0x14a/0x220 softirqs last disabled at (3751): [<ffffffff8101440c>] call_softirq+0x1c/0x30 other info that might help us debug this: 2 locks held by kswapd0/323: #0: (shrinker_rwsem){++++..}, at: [<ffffffff810f67ed>] shrink_slab+0x3d/0x190 #1: (&type->s_umount_key#35){.+.+..}, at: [<ffffffff811429a1>] prune_dcache+0xd1/0x1b0 stack backtrace: Pid: 323, comm: kswapd0 Tainted: G C 2.6.31-2-generic #14~rbd3 Call Trace: [<ffffffff8108ad6c>] print_usage_bug+0x18c/0x1a0 [<ffffffff8108aff0>] ? check_usage_forwards+0x0/0xc0 [<ffffffff8108bac2>] mark_lock_irq+0xf2/0x280 [<ffffffff8108bd87>] mark_lock+0x137/0x1d0 [<ffffffff81164710>] ? fsnotify_clear_marks_by_inode+0x30/0xf0 [<ffffffff8108bee6>] mark_irqflags+0xc6/0x1a0 [<ffffffff8108d337>] __lock_acquire+0x287/0x430 [<ffffffff8108d585>] lock_acquire+0xa5/0x150 [<ffffffff81210d34>] ? ecryptfs_destroy_inode+0x34/0x100 [<ffffffff8108d2e7>] ? __lock_acquire+0x237/0x430 [<ffffffff815526ad>] __mutex_lock_common+0x4d/0x3d0 [<ffffffff81210d34>] ? ecryptfs_destroy_inode+0x34/0x100 [<ffffffff81164710>] ? fsnotify_clear_marks_by_inode+0x30/0xf0 [<ffffffff81210d34>] ? ecryptfs_destroy_inode+0x34/0x100 [<ffffffff8129a91e>] ? _raw_spin_unlock+0x5e/0xb0 [<ffffffff81552b36>] mutex_lock_nested+0x46/0x60 [<ffffffff81210d34>] ecryptfs_destroy_inode+0x34/0x100 [<ffffffff81145d27>] destroy_inode+0x87/0xd0 [<ffffffff81146b4c>] generic_delete_inode+0x12c/0x1a0 [<ffffffff81145832>] iput+0x62/0x70 [<ffffffff811423c8>] dentry_iput+0x98/0x110 [<ffffffff81142550>] d_kill+0x50/0x80 [<ffffffff81142623>] prune_one_dentry+0xa3/0xc0 [<ffffffff811428b1>] __shrink_dcache_sb+0x271/0x290 [<ffffffff811429d9>] prune_dcache+0x109/0x1b0 [<ffffffff81142abf>] shrink_dcache_memory+0x3f/0x50 [<ffffffff810f68dd>] shrink_slab+0x12d/0x190 [<ffffffff810f9377>] balance_pgdat+0x4d7/0x640 [<ffffffff8104c4c0>] ? finish_task_switch+0x40/0x150 [<ffffffff810f63c0>] ? isolate_pages_global+0x0/0x60 [<ffffffff810f95f7>] kswapd+0x117/0x170 [<ffffffff810777a0>] ? autoremove_wake_function+0x0/0x40 [<ffffffff810f94e0>] ? kswapd+0x0/0x170 [<ffffffff810773be>] kthread+0x9e/0xb0 [<ffffffff8101430a>] child_rip+0xa/0x20 [<ffffffff81013c90>] ? restore_args+0x0/0x30 [<ffffffff81077320>] ? kthread+0x0/0xb0 [<ffffffff81014300>] ? child_rip+0x0/0x20 Signed-off-by: Roland Dreier <roland@digitalvampire.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
* | | nfs[23] tcp breakage in mount with binary optionsAl Viro2009-09-241-0/+2
|/ / | | | | | | | | | | | | | | | | | | | | | | We forget to set nfs_server.protocol in tcp case when old-style binary options are passed to mount. The thing remains zero and never validated afterwards. As the result, we hit BUG in fs/nfs/client.c:588. Breakage has been introduced in NFS: Add nfs_alloc_parsed_mount_data merged yesterday... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* | Merge branch 'cputime' of git://git390.marist.edu/pub/scm/linux-2.6Linus Torvalds2009-09-241-1/+6
|\ \ | | | | | | | | | | | | * 'cputime' of git://git390.marist.edu/pub/scm/linux-2.6: [PATCH] Fix idle time field in /proc/uptime
| * | [PATCH] Fix idle time field in /proc/uptimeMichael Abbott2009-09-241-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | Git commit 79741dd changes idle cputime accounting, but unfortunately the /proc/uptime file hasn't caught up. Here the idle time calculation from /proc/stat is copied over. Signed-off-by: Michael Abbott <michael.abbott@diamond.ac.uk> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2009-09-2431-1981/+2740
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (42 commits) Btrfs: hash the btree inode during fill_super Btrfs: relocate file extents in clusters Btrfs: don't rename file into dummy directory Btrfs: check size of inode backref before adding hardlink Btrfs: fix releasepage to avoid unlocking extents we haven't locked Btrfs: Fix test_range_bit for whole file extents Btrfs: fix errors handling cached state in set/clear_extent_bit Btrfs: fix early enospc during balancing Btrfs: deal with NULL space info Btrfs: account for space used by the super mirrors Btrfs: fix extent entry threshold calculation Btrfs: remove dead code Btrfs: fix bitmap size tracking Btrfs: don't keep retrying a block group if we fail to allocate a cluster Btrfs: make balance code choose more wisely when relocating Btrfs: fix arithmetic error in clone ioctl Btrfs: add snapshot/subvolume destroy ioctl Btrfs: change how subvolumes are organized Btrfs: do not reuse objectid of deleted snapshot/subvol Btrfs: speed up snapshot dropping ...
| * \ \ Merge branch 'master' of ↵Chris Mason2009-09-2431-1981/+2740
| |\ \ \ | | |/ / | |/| | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable into for-linus Conflicts: fs/btrfs/super.c
| | * | Btrfs: hash the btree inode during fill_superYan Zheng2009-09-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The snapshot deletion patches dropped this line, but the inode needs to be hashed. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: relocate file extents in clustersYan, Zheng2009-09-241-89/+148
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The extent relocation code copy file extents one by one when relocating data block group. This is inefficient if file extents are small. This patch makes the relocation code copy file extents in clusters. So we can can make better use of read-ahead. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: don't rename file into dummy directoryYan, Zheng2009-09-241-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A recent change enforces only one access point to each subvolume. The first directory entry (the one added when the subvolume/snapshot was created) is treated as valid access point, all other subvolume links are linked to dummy empty directories. The dummy directories are temporary inodes that only in memory, so we can not rename file into them. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: check size of inode backref before adding hardlinkYan, Zheng2009-09-243-24/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For every hardlink in btrfs, there is a corresponding inode back reference. All inode back references for hardlinks in a given directory are stored in single b-tree item. The size of b-tree item is limited by the size of b-tree leaf, so we can only create limited number of hardlinks to a given file in a directory. The original code lacks of the check, it oops if the number of hardlinks goes over the limit. This patch fixes the issue by adding check to btrfs_link and btrfs_rename. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: fix releasepage to avoid unlocking extents we haven't lockedChris Mason2009-09-231-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During releasepage, we try to drop any extent_state structs for the bye offsets of the page we're releaseing. But the code was incorrectly telling clear_extent_bit to delete the state struct unconditionallly. Normally this would be fine because we have the page locked, but other parts of btrfs will lock down an entire extent, the most common place being IO completion. releasepage was deleting the extent state without first locking the extent, which may result in removing a state struct that another process had locked down. The fix here is to leave the NODATASUM and EXTENT_LOCKED bits alone in releasepage. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: Fix test_range_bit for whole file extentsChris Mason2009-09-231-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If test_range_bit finds an extent that goes all the way to (u64)-1, it can incorrectly wrap the u64 instead of treaing it like the end of the address space. This just adds a check for the highest possible offset so we don't wrap. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: fix errors handling cached state in set/clear_extent_bitChris Mason2009-09-231-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both set and clear_extent_bit allow passing a cached state struct to reduce rbtree search times. clear_extent_bit was improperly bypassing some of the checks around making sure the extent state fields were correct for a given operation. The fix used here (from Yan Zheng) is to use the hit_next goto target instead of jumping all the way down to start clearing bits without making sure the cached state was exactly correct for the operation we were doing. This also fixes up the setting of the start variable for both ops in the case where we find an overlapping extent that begins before the range we want to change. In both cases we were incorrectly going backwards from the original requested change. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: fix early enospc during balancingChris Mason2009-09-221-13/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We now do extra checks before a balance to make sure there is room for the balance to take place. One of the checks was testing to see if we were trying to balance away the last block group of a given type. If there is no space available for new chunks, we should not try and balance away the last block group of a give type. But, the code wasn't checking for available chunk space, and so it was exiting too soon. The fix here is to combine some of the checks and make sure we try to allocate new chunks when we're balancing the last block group. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: deal with NULL space infoChris Mason2009-09-221-2/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After a balance it is briefly possible for the space info field in the inode to be NULL. This adds some checks to make sure things properly deal with the NULL value. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: account for space used by the super mirrorsJosef Bacik2009-09-212-2/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As we get closer to proper -ENOSPC handling in btrfs, we need more accurate space accounting for the space info's. Currently we exclude the free space for the super mirrors, but the space they take up isn't accounted for in any of the counters. This patch introduces bytes_super, which keeps track of the amount of bytes used for a super mirror in the block group cache and space info. This makes sure that our free space caclucations will be completely accurate. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: fix extent entry threshold calculationJosef Bacik2009-09-211-14/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a slight problem with the extent entry threshold calculation for the free space cache. We only adjust the threshold down as we add bitmaps, but never actually adjust the threshold up as we add bitmaps. This means we could fragment the free space so badly that we end up using all bitmaps to describe the free space, use all the free space which would result in the bitmaps being freed, but then go to add free space again as we delete things and immediately add bitmaps since the extent threshold would still be 0. Now as we free bitmaps the extent threshold will be ratcheted up to allow more extent entries to be added. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: remove dead codeJosef Bacik2009-09-211-706/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes a bunch of dead code from the snapshot removal stuff. It was confusing me when doing the metadata ENOSPC stuff so I killed it. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: fix bitmap size trackingJosef Bacik2009-09-211-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we first go to add free space, we allocate a new info and set the offset and bytes to the space we are adding. This is fine, except we actually set the size of a bitmap as we set the bits in it, so if we add space to a bitmap, we'd end up counting the same space twice. This isn't a huge deal, it just makes the allocator behave weirdly since it will think that a bitmap entry has more space than it ends up actually having. I used a BUG_ON() to catch when this problem happened, and with this patch I no longer get the BUG_ON(). Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: don't keep retrying a block group if we fail to allocate a clusterJosef Bacik2009-09-211-8/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The box can get locked up in the allocator if we happen upon a block group under these conditions: 1) During a commit, so caching threads cannot make progress 2) Our block group currently is in the middle of being cached 3) Our block group currently has plenty of free space in it 4) Our block group is so fragmented that it ends up having no free space chunks larger than min_bytes calculated by btrfs_find_space_cluster. What happens is we try and do btrfs_find_space_cluster, which fails because it is unable to find enough free space chunks that are large than min_bytes and are close enough together. Since the block group is not cached we do a wait_block_group_cache_progress, which waits for the number of bytes we need, except the block group already has _plenty_ of free space, its just severely fragmented, so we loop and try again, ad infinitum. This patch keeps us from waiting on the block group to finish caching if we failed to find a free space cluster before. It also makes sure that we don't even try to find a free space cluster if we are on our last loop in the allocator, since we will have tried everything at this point at it is futile. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: make balance code choose more wisely when relocatingJosef Bacik2009-09-214-18/+148
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, we can panic the box if the first block group we go to move is of a type where there is no space left to move those extents. For example, if we fill the disk up with data, and then we try to balance and we have no room to move the data nor room to allocate new chunks, we will panic. Change this by checking to see if we have room to move this chunk around, and if not, return -ENOSPC and move on to the next chunk. This will make sure we remove block groups that are moveable, like if we have alot of empty metadata block groups, and then that way we make room to be able to balance our data chunks as well. Tested this with an fs that would panic on btrfs-vol -b normally, but no longer panics with this patch. V1->V2: -actually search for a free extent on the device to make sure we can allocate a chunk if need be. -fix btrfs_shrink_device to make sure we actually try to relocate all the chunks, and then if we can't return -ENOSPC so if we are doing a btrfs-vol -r we don't remove the device with data still on it. -check to make sure the block group we are going to relocate isn't the last one in that particular space -fix a bug in btrfs_shrink_device where we would change the device's size and not fix it if we fail to do our relocate Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: fix arithmetic error in clone ioctlSage Weil2009-09-211-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix an arithmetic error that was breaking extents cloned via the clone ioctl starting in the second half of a file. Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: add snapshot/subvolume destroy ioctlYan, Zheng2009-09-2112-233/+605
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds snapshot/subvolume destroy ioctl. A subvolume that isn't being used and doesn't contains links to other subvolumes can be destroyed. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: change how subvolumes are organizedYan, Zheng2009-09-219-168/+459
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | btrfs allows subvolumes and snapshots anywhere in the directory tree. If we snapshot a subvolume that contains a link to other subvolume called subvolA, subvolA can be accessed through both the original subvolume and the snapshot. This is similar to creating hard link to directory, and has the very similar problems. The aim of this patch is enforcing there is only one access point to each subvolume. Only the first directory entry (the one added when the subvolume/snapshot was created) is treated as valid access point. The first directory entry is distinguished by checking root forward reference. If the corresponding root forward reference is missing, we know the entry is not the first one. This patch also adds snapshot/subvolume rename support, the code allows rename subvolume link across subvolumes. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: do not reuse objectid of deleted snapshot/subvolYan, Zheng2009-09-216-116/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new back reference format does not allow reusing objectid of deleted snapshot/subvol. So we use ++highest_objectid to allocate objectid for new snapshot/subvol. Now we use ++highest_objectid to allocate objectid for both new inode and new snapshot/subvolume, so this patch removes 'find hole' code in btrfs_find_free_objectid. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: speed up snapshot droppingYan, Zheng2009-09-212-49/+207
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch contains two changes to avoid unnecessary tree block reads during snapshot dropping. First, check tree block's reference count and flags before reading the tree block. if reference count > 1 and there is no need to update backrefs, we can avoid reading the tree block. Second, save when snapshot was created in root_key.offset. we can compare block pointer's generation with snapshot's creation generation during updating backrefs. If a given block was created before snapshot was created, the snapshot can't be the tree block's owner. So we can avoid reading the block. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * | Btrfs: search for an allocation hint while filling file COWChris Mason2009-09-183-1/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The allocator has some nice knobs for sending hints about where to try and allocate new blocks, but when we're doing file allocations we're not sending any hint at all. This commit adds a simple extent map search to see if we can quickly and easily find a hint for the allocator. Signed-off-by: Chris Mason <chris.mason@oracle.com>
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