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path: root/fs/btrfs/backref.c
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2012-06-14Btrfs: add btrfs_next_old_leafJan Schmidt1-3/+4
To make sense of the tree mod log, the backref walker not only needs btrfs_search_old_slot, but it also called btrfs_next_leaf, which in turn was calling btrfs_search_slot. This obviously didn't give the correct result. This commit adds btrfs_next_old_leaf, a drop-in replacement for btrfs_next_leaf with a time_seq parameter. If it is zero, it behaves exactly like btrfs_next_leaf. If it is non-zero, it will use btrfs_search_old_slot with this time_seq parameter. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-06-14Btrfs: remove obsolete btrfs_next_leaf call from __resolve_indirect_refJan Schmidt1-9/+1
When resolving indirect refs, we used to call btrfs_next_leaf in case we didn't find an exact match. While we should find exact matches most of the time, in case we don't, we must continue searching. Treating those matches differently depending on the level we're searching doesn't make sense. Even worse, we might end up searching for a key larger than the largest, in which case there is no next_leaf and subsequent jobs would fail. This commit drops the bogous lines. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-31Btrfs: add inodes before dropping the extent lock in find_all_leafsJan Schmidt1-5/+31
We must build up the inode list with the extent lock held after following indirect refs. This also requires an extension to ulists, which allows to modify the stored aux value in case a key already exists in the list. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-30Btrfs: use the tree modification log for backref resolvingJan Schmidt1-16/+27
This enables backref resolving on life trees while they are changing. This is a prerequisite for quota groups and just nice to have for everything else. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-26Btrfs: look into the extent during find_all_leafsJan Schmidt1-83/+157
Before this patch we called find_all_leafs for a data extent, then called find_all_roots and then looked into the extent to grab the information we were seeking. This was done without holding the leaves locked to avoid deadlocks. However, this can obviouly race with concurrent tree modifications. Instead, we now look into the extent while we're holding the lock during find_all_leafs and store this information together with the leaf list. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-26Btrfs: bugfix: ignore the wrong key for indirect tree block backrefsJan Schmidt1-50/+135
The key we store with a tree block backref is only a hint. It is set when the ref is created and can remain correct for a long time. As the tree is rebalanced, however, eventually the key no longer points to the correct destination. With this patch, we change find_parent_nodes to no longer add keys unless it knows for sure they're correct (e.g. because they're for an extent data backref). Then when we later encounter a backref ref with no parent and no key set, we grab the block and take the first key from the block itself. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-26Btrfs: bugfix in btrfs_find_parent_nodesJan Schmidt1-2/+3
That one has been around since the addition of backref.c. Due to the way we calculate our slot numbers, after adding inline refs we're missing one keyed ref unless it's located at the beginning of a new leaf. Reported-by: Alexander Block <ablock84@googlemail.com> Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-26Btrfs: ulist realloc bugfixJan Schmidt1-5/+13
ulist_next gets the pointer to the previously returned element to find the next element from there. However, when we call ulist_add while iteration with ulist_next is in progress (ulist explicitly supports this), we can realloc the ulist internal memory, which makes the pointer to the previous element useless. Instead, we now use an iterator parameter that's independent from the internal pointers. Reported-by: Alexander Block <ablock84@googlemail.com> Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-04-18Btrfs: add missing read locks in backref.cJan Schmidt1-2/+15
iref_to_path and iterate_irefs both increment the eb's refcount to use it after releasing the path. Both depend on consistent data remaining in the extent buffer and need a read lock to protect it. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-04-18Btrfs: don't call free_extent_buffer twice in iterate_irefsJan Schmidt1-5/+3
Avoid calling free_extent_buffer more than once when the iterator function returns non-zero. The only code that uses this is scrub repair for corrupted nodatasum blocks. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-04-18Btrfs: Make free_ipath() deal gracefully with NULL pointersJesper Juhl1-0/+2
Make free_ipath() behave like most other freeing functions in the kernel and gracefully do nothing when passed a NULL pointer. Besides this making the bahaviour consistent with functions such as kfree(), vfree(), btrfs_free_path() etc etc, it also fixes a real NULL deref issue in fs/btrfs/ioctl.c::btrfs_ioctl_ino_to_path(). In that function we have this code: ... ipath = init_ipath(size, root, path); if (IS_ERR(ipath)) { ret = PTR_ERR(ipath); ipath = NULL; goto out; } ... out: btrfs_free_path(path); free_ipath(ipath); ... If we ever take the true branch of that 'if' statement we'll end up passing a NULL pointer to free_ipath() which will subsequently dereference it and we'll go "Boom" :-( This patch will avoid that. Signed-off-by: Jesper Juhl <jj@chaosbits.net>
2012-03-28Merge git://git.jan-o-sch.net/btrfs-unstable into for-linusChris Mason1-49/+66
Conflicts: fs/btrfs/transaction.c Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-27Btrfs: fix memory leak in resolver codeIlya Dryomov1-6/+1
init_ipath() allocates btrfs_data_container which is never freed. Free it in free_ipath() and nuke the comment for init_data_container() - we can safely free it with kfree(). Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-03-27Btrfs: fix regression in scrub path resolvingJan Schmidt1-49/+66
In commit 4692cf58 we introduced new backref walking code for btrfs. This assumes we're searching live roots, which requires a transaction context. While scrubbing, however, we must not join a transaction because this could deadlock with the commit path. Additionally, what scrub really wants to do is resolving a logical address in the commit root it's currently checking. This patch adds support for logical to path resolving on commit roots and makes scrub use that. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-03-03btrfs: fix locking issues in find_parent_nodes()Li Zefan1-2/+6
- We might unlock head->mutex while it was not locked - We might leave the function without unlocking delayed_refs->lock Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-02-15Btrfs: avoid positive number with ERR_PTRJan Schmidt1-0/+2
inode_ref_info() returns 1 when the element wasn't found and < 0 on error, just like btrfs_search_slot(). In iref_to_path() it's an error when the inode ref can't be found, thus we return ERR_PTR(ret) in that case. In order to avoid ERR_PTR(1), we now set ret to -ENOENT in that case. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-01-26Btrfs: fix uninit warning in backref.cJan Schmidt1-2/+2
Added initialization with the declaration of ret. It isn't set later on the switch-default branch (which should never be taken). Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-01-05Btrfs: new backref walking codeJan Schmidt1-256/+98
The old backref iteration code could only safely be used on commit roots. Besides this limitation, it had bugs in finding the roots for these references. This commit replaces large parts of it by btrfs_find_all_roots() which a) really finds all roots and the correct roots, b) works correctly under heavy file system load, c) considers delayed refs. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-01-04Btrfs: added btrfs_find_all_roots()Jan Schmidt1-0/+783
This function gets a byte number (a data extent), collects all the leafs pointing to it and walks up the trees to find all fs roots pointing to those leafs. It also returns the list of all leafs pointing to that extent. It does proper locking for the involved trees, can be used on busy file systems and honors delayed refs. Signed-off-by: Arne Jansen <sensille@gmx.net> Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2011-11-20btrfs: Fix up 32/64-bit compatibility for new ioctlsJeff Mahoney1-1/+1
This patch casts to unsigned long before casting to a pointer and fixes the following warnings: fs/btrfs/extent_io.c:2289:20: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] fs/btrfs/ioctl.c:2933:37: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] fs/btrfs/ioctl.c:2937:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] fs/btrfs/ioctl.c:3020:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] fs/btrfs/scrub.c:275:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] fs/btrfs/backref.c:686:27: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-11-06Btrfs: fix the new inspection ioctls for 32 bit compatChris Mason1-4/+4
The new ioctls to follow backrefs are not clean for 32/64 bit compat. This reworks them for u64s everywhere. They are brand new, so there are no problems with changing the interface now. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-09-29btrfs: added helper functions to iterate backrefsJan Schmidt1-0/+776
These helper functions iterate back references and call a function for each backref. There is also a function to resolve an inode to a path in the file system. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>