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path: root/fs/btrfs/uuid-tree.c (follow)
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* btrfs: return the actual error value from from btrfs_uuid_tree_iteratePan Bian2016-12-191-3/+1
| | | | | | | | | | | | | In function btrfs_uuid_tree_iterate(), errno is assigned to variable ret on errors. However, it directly returns 0. It may be better to return ret. This patch also removes the warning, because the caller already prints a warning. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188731 Signed-off-by: Pan Bian <bianpan2016@163.com> Reviewed-by: Omar Sandoval <osandov@fb.com> [ edited subject ] Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: remove root parameter from transaction commit/end routinesJeff Mahoney2016-12-061-1/+1
| | | | | | | | | | Now we only use the root parameter to print the root objectid in a tracepoint. We can use the root parameter from the transaction handle for that. It's also used to join the transaction with async commits, so we remove the comment that it's just for checking. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: take an fs_info directly when the root is not used otherwiseJeff Mahoney2016-12-061-2/+2
| | | | | | | | | There are loads of functions in btrfs that accept a root parameter but only use it to obtain an fs_info pointer. Let's convert those to just accept an fs_info pointer directly. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: root->fs_info cleanup, add fs_info convenience variablesJeff Mahoney2016-12-061-4/+3
| | | | | | | | | In routines where someptr->fs_info is referenced multiple times, we introduce a convenience variable. This makes the code considerably more readable. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: call functions that always use the same root with fs_info insteadJeff Mahoney2016-12-061-4/+6
| | | | | | | | | | There are many functions that are always called with the same root argument. Rather than passing the same root every time, we can pass an fs_info pointer instead and have the function get the root pointer itself. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: unsplit printed stringsJeff Mahoney2016-09-261-12/+15
| | | | | | | | | | | CodingStyle chapter 2: "[...] never break user-visible strings such as printk messages, because that breaks the ability to grep for them." This patch unsplits user-visible strings. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: make btrfs_search_forward return with nodes unlockedFilipe Manana2014-09-171-1/+0
| | | | | | | | | | | | | | | | | | | | None of the uses of btrfs_search_forward() need to have the path nodes (level >= 1) read locked, only the leaf needs to be locked while the caller processes it. Therefore make it return a path with all nodes unlocked, except for the leaf. This change is motivated by the observation that during a file fsync we repeatdly call btrfs_search_forward() and process the returned leaf while upper nodes of the returned path (level >= 1) are read locked, which unnecessarily blocks other tasks that want to write to the same fs/subvol btree. Therefore instead of modifying the fsync code to unlock all nodes with level >= 1 immediately after calling btrfs_search_forward(), change btrfs_search_forward() to do it, so that it benefits all callers. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: convert printk to btrfs_ and fix BTRFS prefixFrank Holton2014-01-281-6/+7
| | | | | | | | | | Convert all applicable cases of printk and pr_* to the btrfs_* macros. Fix all uses of the BTRFS prefix. Signed-off-by: Frank Holton <fholton@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: remove unused max_key arg from btrfs_search_forwardFilipe David Borba Manana2013-11-121-5/+1
| | | | | | | | It is not used for anything. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: check UUID tree during mount if requiredStefan Behrens2013-09-011-0/+123
| | | | | | | | | | | | | | | | | | | | | | | | If the filesystem was mounted with an old kernel that was not aware of the UUID tree, this is detected by looking at the uuid_tree_generation field of the superblock (similar to how the free space cache is doing it). If a mismatch is detected at mount time, a thread is started that does two things: 1. Iterate through the UUID tree, check each entry, delete those entries that are not valid anymore (i.e., the subvol does not exist anymore or the value changed). 2. Iterate through the root tree, for each found subvolume, add the UUID tree entries for the subvolume (if they are not already there). This mechanism is also used to handle and repair errors that happened during the initial creation and filling of the tree. The update of the uuid_tree_generation field (which indicates that the state of the UUID tree is up to date) is blocked until all create and repair operations are successfully completed. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: introduce a tree for items that map UUIDs to somethingStefan Behrens2013-09-011-0/+235
Mapping UUIDs to subvolume IDs is an operation with a high effort today. Today, the algorithm even has quadratic effort (based on the number of existing subvolumes), which means, that it takes minutes to send/receive a single subvolume if 10,000 subvolumes exist. But even linear effort would be too much since it is a waste. And these data structures to allow mapping UUIDs to subvolume IDs are created every time a btrfs send/receive instance is started. It is much more efficient to maintain a searchable persistent data structure in the filesystem, one that is updated whenever a subvolume/snapshot is created and deleted, and when the received subvolume UUID is set by the btrfs-receive tool. Therefore kernel code is added with this commit that is able to maintain data structures in the filesystem that allow to quickly search for a given UUID and to retrieve data that is assigned to this UUID, like which subvolume ID is related to this UUID. This commit adds a new tree to hold UUID-to-data mapping items. The key of the items is the full UUID plus the key type BTRFS_UUID_KEY. Multiple data blocks can be stored for a given UUID, a type/length/ value scheme is used. Now follows the lengthy justification, why a new tree was added instead of using the existing root tree: The first approach was to not create another tree that holds UUID items. Instead, the items should just go into the top root tree. Unfortunately this confused the algorithm to assign the objectid of subvolumes and snapshots. The reason is that btrfs_find_free_objectid() calls btrfs_find_highest_objectid() for the first created subvol or snapshot after mounting a filesystem, and this function simply searches for the largest used objectid in the root tree keys to pick the next objectid to assign. Of course, the UUID keys have always been the ones with the highest offset value, and the next assigned subvol ID was wastefully huge. To use any other existing tree did not look proper. To apply a workaround such as setting the objectid to zero in the UUID item key and to implement collision handling would either add limitations (in case of a btrfs_extend_item() approach to handle the collisions) or a lot of complexity and source code (in case a key would be looked up that is free of collisions). Adding new code that introduces limitations is not good, and adding code that is complex and lengthy for no good reason is also not good. That's the justification why a completely new tree was introduced. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>