kernel/git/stable/linux.git/fs/btrfs/send.c, branch linux-3.12.y

Btrfs: send, don't BUG_ON() when an empty symlink is found

2016-03-03T11:46:00+00:00

commit a879719b8c90e15c9e7fa7266d5e3c0ca962f9df upstream. When a symlink is successfully created it always has an inline extent containing the source path. However if an error happens when creating the symlink, we can leave in the subvolume's tree a symlink inode without any such inline extent item - this happens if after btrfs_symlink() calls btrfs_end_transaction() and before it calls the inode eviction handler (through the final iput() call), the transaction gets committed and a crash happens before the eviction handler gets called, or if a snapshot of the subvolume is made before the eviction handler gets called. Sadly we can't just avoid this by making btrfs_symlink() call btrfs_end_transaction() after it calls the eviction handler, because the later can commit the current transaction before it removes any items from the subvolume tree (if it encounters ENOSPC errors while reserving space for removing all the items). So make send fail more gracefully, with an -EIO error, and print a message to dmesg/syslog informing that there's an empty symlink inode, so that the user can delete the empty symlink or do something else about it. Reported-by: Stephen R. van den Berg Signed-off-by: Filipe Manana Signed-off-by: Jiri Slaby

Btrfs: send, don't error in the presence of subvols/snapshots

2014-07-02T10:06:39+00:00

commit 1af56070e3ef9477dbc7eba3b9ad7446979c7974 upstream. If we are doing an incremental send and the base snapshot has a directory with name X that doesn't exist anymore in the second snapshot and a new subvolume/snapshot exists in the second snapshot that has the same name as the directory (name X), the incremental send would fail with -ENOENT error. This is because it attempts to lookup for an inode with a number matching the objectid of a root, which doesn't exist. Steps to reproduce: mkfs.btrfs -f /dev/sdd mount /dev/sdd /mnt mkdir /mnt/testdir btrfs subvolume snapshot -r /mnt /mnt/mysnap1 rmdir /mnt/testdir btrfs subvolume create /mnt/testdir btrfs subvolume snapshot -r /mnt /mnt/mysnap2 btrfs send -p /mnt/mysnap1 /mnt/mysnap2 -f /tmp/send.data A test case for xfstests follows. Reported-by: Robert White Signed-off-by: Filipe David Borba Manana Signed-off-by: Chris Mason Signed-off-by: Jiri Slaby

Btrfs: stop using vfs_read in send

2013-12-20T15:49:09+00:00

commit ed2590953bd06b892f0411fc94e19175d32f197a upstream. Apparently we don't actually close the files until we return to userspace, so stop using vfs_read in send. This is actually better for us since we can avoid all the extra logic of holding the file we're sending open and making sure to clean it up. This will fix people who have been hitting too many files open errors when trying to send. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason Signed-off-by: Greg Kroah-Hartman

Btrfs: fix access_ok() check in btrfs_ioctl_send()

2013-12-20T15:49:03+00:00

commit 700ff4f095d78af0998953e922e041d75254518b upstream. The closing parenthesis is in the wrong place. We want to check "sizeof(*arg->clone_sources) * arg->clone_sources_count" instead of "sizeof(*arg->clone_sources * arg->clone_sources_count)". Signed-off-by: Dan Carpenter Reviewed-by: Jie Liu Signed-off-by: Chris Mason Signed-off-by: Greg Kroah-Hartman

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

2013-09-12T16:58:51+00:00

Pull btrfs updates from Chris Mason: "This is against 3.11-rc7, but was pulled and tested against your tree as of yesterday. We do have two small incrementals queued up, but I wanted to get this bunch out the door before I hop on an airplane. This is a fairly large batch of fixes, performance improvements, and cleanups from the usual Btrfs suspects. We've included Stefan Behren's work to index subvolume UUIDs, which is targeted at speeding up send/receive with many subvolumes or snapshots in place. It closes a long standing performance issue that was built in to the disk format. Mark Fasheh's offline dedup work is also here. In this case offline means the FS is mounted and active, but the dedup work is not done inline during file IO. This is a building block where utilities are able to ask the FS to dedup a series of extents. The kernel takes care of verifying the data involved really is the same. Today this involves reading both extents, but we'll continue to evolve the patches" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (118 commits) Btrfs: optimize key searches in btrfs_search_slot Btrfs: don't use an async starter for most of our workers Btrfs: only update disk_i_size as we remove extents Btrfs: fix deadlock in uuid scan kthread Btrfs: stop refusing the relocation of chunk 0 Btrfs: fix memory leak of uuid_root in free_fs_info btrfs: reuse kbasename helper btrfs: return btrfs error code for dev excl ops err Btrfs: allow partial ordered extent completion Btrfs: convert all bug_ons in free-space-cache.c Btrfs: add support for asserts Btrfs: adjust the fs_devices->missing count on unmount Btrf: cleanup: don't check for root_refs == 0 twice Btrfs: fix for patch "cleanup: don't check the same thing twice" Btrfs: get rid of one BUG() in write_all_supers() Btrfs: allocate prelim_ref with a slab allocater Btrfs: pass gfp_t to __add_prelim_ref() to avoid always using GFP_ATOMIC Btrfs: fix race conditions in BTRFS_IOC_FS_INFO ioctl Btrfs: fix race between removing a dev and writing sbs Btrfs: remove ourselves from the cluster list under lock ...

btrfs: reuse kbasename helper

2013-09-01T12:16:36+00:00

To get name of the file from a pathname let's use kbasename() helper. It allows to simplify code a bit. Signed-off-by: Andy Shevchenko Signed-off-by: Josef Bacik Signed-off-by: Chris Mason

Btrfs: fix send to deal with sparse files properly

2013-09-01T12:16:21+00:00

Send was just sending everything it found, even if the extent was a hole. This is unpleasant for users, so just skip holes when we are sending. This will also skip sending prealloc extents since the send spec doesn't have a prealloc command. Eventually we will add a prealloc command and rev the send version so we can send down the prealloc info. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason

Btrfs: get rid of sparse warnings

2013-09-01T12:15:50+00:00

make C=2 fs/btrfs/ CF=-D__CHECK_ENDIAN__ I tried to filter out the warnings for which patches have already been sent to the mailing list, pending for inclusion in btrfs-next. All these changes should be obviously safe. Signed-off-by: Stefan Behrens Signed-off-by: Josef Bacik Signed-off-by: Chris Mason

Btrfs: fix send issues related to inode number reuse

2013-09-01T12:15:44+00:00

If you are sending a snapshot and specifying a parent snapshot we will walk the trees and figure out where they differ and send the differences only. The way we check for differences are if the leaves aren't the same and if the keys are not the same within the leaves. So if neither leaf is the same (ie the leaf has been cow'ed from the parent snapshot) we walk each item in the send root and check it against the parent root. If the items match exactly then we don't do anything. This doesn't quite work for inode refs, since they will just have the name and the parent objectid. If you move the file from a directory and then remove that directory and re-create a directory with the same inode number as the old directory and then move that file back into that directory we will assume that nothing changed and you will get errors when you try to receive. In order to fix this we need to do extra checking to see if the inode ref really is the same or not. So do this by passing down BTRFS_COMPARE_TREE_SAME if the items match. Then if the key type is an inode ref we can do some extra checking, otherwise we just keep processing. The extra checking is to look up the generation of the directory in the parent volume and compare it to the generation of the send volume. If they match then they are the same directory and we are good to go. If they don't we have to add them to the changed refs list. This means we have to track the generation of the ref we're trying to lookup when we iterate all the refs for a particular inode. So in the case of looking for new refs we have to get the generation from the parent volume, and in the case of looking for deleted refs we have to get the generation from the send volume to compare with. There was also the issue of using a ulist to keep track of the directories we needed to check. Because we can get a deleted ref and a new ref for the same inode number the ulist won't work since it indexes based on the value. So instead just dup any directory ref we find and add it to a local list, and then process that list as normal and do away with using a ulist for this altogether. Before we would fail all of the tests in the far-progs that related to moving directories (test group 32). With this patch we now pass these tests, and all of the tests in the far-progs send testing suite. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason

Btrfs: skip subvol entries when checking if we've created a dir already

2013-09-01T12:05:01+00:00

We have logic to see if we've already created a parent directory by check to see if an inode inside of that directory has a lower inode number than the one we are currently processing. The logic is that if there is a lower inode number then we would have had to made sure the directory was created at that previous point. The problem is that subvols inode numbers count from the lowest objectid in the root tree, which may be less than our current progress. So just skip if our dir item key is a root item. This fixes the original test and the xfstest version I made that added an extra subvol create. Thanks, Reported-by: Emil Karlson Signed-off-by: Josef Bacik Signed-off-by: Chris Mason