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path: root/fs/btrfs/ioctl.c
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2009-06-11Btrfs: fix oops when btrfs_inherit_iflags called with a NULL dirChris Mason
This happens during subvol creation. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: implement FS_IOC_GETFLAGS/SETFLAGS/GETVERSIONChristoph Hellwig
Add support for the standard attributes set via chattr and read via lsattr. Currently we store the attributes in the flags value in the btrfs inode, but I wonder whether we should split it into two so that we don't have to keep converting between the two formats. Remove the btrfs_clear_flag/btrfs_set_flag/btrfs_test_flag macros as they were confusing the existing code and got in the way of the new additions. Also add the FS_IOC_GETVERSION ioctl for getting i_generation as it's trivial. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE)Yan Zheng
This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-05-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: Spelling fix in btrfs_lookup_first_block_group comments Btrfs: make show_options result match actual option names Btrfs: remove outdated comment in btrfs_ioctl_resize() Btrfs: remove some WARN_ONs in the IO failure path Btrfs: Don't loop forever on metadata IO failures Btrfs: init inode ordered_data_close flag properly
2009-05-14Btrfs: remove outdated comment in btrfs_ioctl_resize()Li Hong
In Li Zefan's commit dae7b665cf6d6e6e733f1c9c16cf55547dd37e33, a combination call of kmalloc() and copy_from_user() is replaced by memdup_user(). So btrfs_ioctl_resize() doesn't use GFP_NOFS any more. Signed-off-by: Li Hong <lihong.hi@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: look for acls during btrfs_read_locked_inode Btrfs: fix acl caching Btrfs: Fix a bunch of printk() warnings. Btrfs: Fix a trivial warning using max() of u64 vs ULL. Btrfs: remove unused btrfs_bit_radix slab Btrfs: ratelimit IO error printks Btrfs: remove #if 0 code Btrfs: When shrinking, only update disk size on success Btrfs: fix deadlocks and stalls on dead root removal Btrfs: fix fallocate deadlock on inode extent lock Btrfs: kill btrfs_cache_create Btrfs: don't export symbols Btrfs: simplify makefile Btrfs: try to keep a healthy ratio of metadata vs data block groups
2009-04-27Btrfs: Fix a bunch of printk() warnings.Joel Becker
Just happened to notice a bunch of %llu vs u64 warnings. Here's a patch to cast them all. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24Btrfs: fix fallocate deadlock on inode extent lockChris Mason
The btrfs fallocate call takes an extent lock on the entire range being fallocated, and then runs through insert_reserved_extent on each extent as they are allocated. The problem with this is that btrfs_drop_extents may decide to try and take the same extent lock fallocate was already holding. The solution used here is to push down knowledge of the range that is already locked going into btrfs_drop_extents. It turns out that at least one other caller had the same bug. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-20btrfs: use memdup_user()Li Zefan
Remove open-coded memdup_user(). Note this changes some GFP_NOFS to GFP_KERNEL, since copy_from_user() may cause pagefault, it's pointless to pass GFP_NOFS to kmalloc(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31New helper - current_umask()Al Viro
current->fs->umask is what most of fs_struct users are doing. Put that into a helper function. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-02-20Btrfs: add better -ENOSPC handlingJosef Bacik
This is a step in the direction of better -ENOSPC handling. Instead of checking the global bytes counter we check the space_info bytes counters to make sure we have enough space. If we don't we go ahead and try to allocate a new chunk, and then if that fails we return -ENOSPC. This patch adds two counters to btrfs_space_info, bytes_delalloc and bytes_may_use. bytes_delalloc account for extents we've actually setup for delalloc and will be allocated at some point down the line. bytes_may_use is to keep track of how many bytes we may use for delalloc at some point. When we actually set the extent_bit for the delalloc bytes we subtract the reserved bytes from the bytes_may_use counter. This keeps us from not actually being able to allocate space for any delalloc bytes. Signed-off-by: Josef Bacik <jbacik@redhat.com>
2009-01-21Btrfs: removed unused #include <version.h>'sHuang Weiyi
Removed unused #include <version.h>'s in btrfs Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-05Btrfs: Fix checkpatch.pl warningsChris Mason
There were many, most are fixed now. struct-funcs.c generates some warnings but these are bogus. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-05Btrfs: update directory's size when creating subvol/snapshotYan Zheng
Make sure directory's size properly updated when creating subvol/snapshot. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2009-01-05Btrfs: add permission checks to the ioctlsChris Mason
Only root can add/remove devices Only root can defrag subtrees Only files open for writing can be defragged Only files open for writing can be the destination for a clone Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-19Btrfs: Add missing mnt_drop_write in ioctl.cYan Zheng
This patch adds the missing mnt_drop_write to match mnt_want_write in btrfs_ioctl_defrag and btrfs_ioctl_clone Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-12-11Btrfs: fix leaking block group on balanceYan Zheng
The block group structs are referenced in many different places, and it's not safe to free while balancing. So, those block group structs were simply leaked instead. This patch replaces the block group pointer in the inode with the starting byte offset of the block group and adds reference counting to the block group struct. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-12-11Btrfs: mnt_drop_write in ioctl_trans_endSage Weil
Add missing mnt_drop_write to match the mnt_want_write in btrfs_ioctl_trans_start. Signed-off-by: Sage Weil <sage@newdream.net>
2008-12-08Btrfs: move data checksumming into a dedicated treeChris Mason
Btrfs stores checksums for each data block. Until now, they have been stored in the subvolume trees, indexed by the inode that is referencing the data block. This means that when we read the inode, we've probably read in at least some checksums as well. But, this has a few problems: * The checksums are indexed by logical offset in the file. When compression is on, this means we have to do the expensive checksumming on the uncompressed data. It would be faster if we could checksum the compressed data instead. * If we implement encryption, we'll be checksumming the plain text and storing that on disk. This is significantly less secure. * For either compression or encryption, we have to get the plain text back before we can verify the checksum as correct. This makes the raid layer balancing and extent moving much more expensive. * It makes the front end caching code more complex, as we have touch the subvolume and inodes as we cache extents. * There is potentitally one copy of the checksum in each subvolume referencing an extent. The solution used here is to store the extent checksums in a dedicated tree. This allows us to index the checksums by phyiscal extent start and length. It means: * The checksum is against the data stored on disk, after any compression or encryption is done. * The checksum is stored in a central location, and can be verified without following back references, or reading inodes. This makes compression significantly faster by reducing the amount of data that needs to be checksummed. It will also allow much faster raid management code in general. The checksums are indexed by a key with a fixed objectid (a magic value in ctree.h) and offset set to the starting byte of the extent. This allows us to copy the checksum items into the fsync log tree directly (or any other tree), without having to invent a second format for them. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-02Btrfs: add support for multiple csum algorithmsJosef Bacik
This patch gives us the space we will need in order to have different csum algorithims at some point in the future. We save the csum algorithim type in the superblock, and use those instead of define's. Signed-off-by: Josef Bacik <jbacik@redhat.com>
2008-12-02Btrfs: btrfs: pass void __user * to btrfs_ioctl_clone_rangeChristoph Hellwig
Cleans the code up a little and also avoids a sparse warning due to the incorrect cast in the current version of the code. Signed-off-by: Christoph Hellwig <hch@lst.de>
2008-12-02Btrfs: clean up btrfs_ioctl a little bitChristoph Hellwig
Provide a void __user *argp pointer so that we can avoid duplicating the cast for various sub-command calls. Signed-off-by: Christoph Hellwig <hch@lst.de>
2008-12-02Btrfs: make things static and include the right headersChristoph Hellwig
Shut up various sparse warnings about symbols that should be either static or have their declarations in scope. Signed-off-by: Christoph Hellwig <hch@lst.de>
2008-12-02Btrfs: remove unneeded btrfs_start_delalloc_inodes callSage Weil
It is called by btrfs_sync_fs. Signed-off-by: Sage Weil <sage@newdream.net>
2008-11-20Btrfs: compat code fixesChris Mason
The btrfs git kernel trees is used to build a standalone tree for compiling against older kernels. This commit makes the standalone tree work with 2.6.27 Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17Btrfs: prevent loops in the directory tree when creating snapshotsChris Mason
For a directory tree: /mnt/subvolA/subvolB btrfsctl -s /mnt/subvolA/subvolB /mnt Will create a directory loop with subvolA under subvolB. This commit uses the forward refs for each subvol and snapshot to error out before creating the loop. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17Btrfs: Add backrefs and forward refs for subvols and snapshotsChris Mason
Subvols and snapshots can now be referenced from any point in the directory tree. We need to maintain back refs for them so we can find lost subvols. Forward refs are added so that we know all of the subvols and snapshots referenced anywhere in the directory tree of a single subvol. This can be used to do recursive snapshotting (but they aren't yet) and it is also used to detect and prevent directory loops when creating new snapshots. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17Btrfs: Give each subvol and snapshot their own anonymous devidChris Mason
Each subvolume has its own private inode number space, and so we need to fill in different device numbers for each subvolume to avoid confusing applications. This commit puts a struct super_block into struct btrfs_root so it can call set_anon_super() and get a different device number generated for each root. btrfs_rename is changed to prevent renames across subvols. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17Btrfs: Allow subvolumes and snapshots anywhere in the directory treeChris Mason
Before, all snapshots and subvolumes lived in a single flat directory. This was awkward and confusing because the single flat directory was only writable with the ioctls. This commit changes the ioctls to create subvols and snapshots at any point in the directory tree. This requires making separate ioctls for snapshot and subvol creation instead of a combining them into one. The subvol ioctl does: btrfsctl -S subvol_name parent_dir After the ioctl is done subvol_name lives inside parent_dir. The snapshot ioctl does: btrfsctl -s path_for_snapshot root_to_snapshot path_for_snapshot can be an absolute or relative path. btrfsctl breaks it up into directory and basename components. root_to_snapshot can be any file or directory in the FS. The snapshot is taken of the entire root where that file lives. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17Btrfs: Seed device supportYan Zheng
Seed device is a special btrfs with SEEDING super flag set and can only be mounted in read-only mode. Seed devices allow people to create new btrfs on top of it. The new FS contains the same contents as the seed device, but it can be mounted in read-write mode. This patch does the following: 1) split code in btrfs_alloc_chunk into two parts. The first part does makes the newly allocated chunk usable, but does not do any operation that modifies the chunk tree. The second part does the the chunk tree modifications. This division is for the bootstrap step of adding storage to the seed device. 2) Update device management code to handle seed device. The basic idea is: For an FS grown from seed devices, its seed devices are put into a list. Seed devices are opened on demand at mounting time. If any seed device is missing or has been changed, btrfs kernel module will refuse to mount the FS. 3) make btrfs_find_block_group not return NULL when all block groups are read-only. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-11-12Btrfs: mount ro and remount supportYan Zheng
This patch adds mount ro and remount support. The main changes in patch are: adding btrfs_remount and related helper function; splitting the transaction related code out of close_ctree into btrfs_commit_super; updating allocator to properly handle read only block group. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-11-12Btrfs: allow clone of an arbitrary file rangeSage Weil
This patch adds an additional CLONE_RANGE ioctl to clone an arbitrary (block-aligned) file range to another file. The original CLONE ioctl becomes a special case of cloning the entire file range. The logic is a bit more complex now since ranges may be cloned to different offsets, and because we may only be cloning the beginning or end of a particular extent or checksum item. An additional sanity check ensures the source and destination files aren't the same (which would previously deadlock), although eventually this could be extended to allow the duplication of file data at a different offset within the same file. Any extents within the destination range in the target file are dropped. We currently do not cope with the case where a compressed inline extent needs to be split. This will probably require decompressing the extent into a temporary address_space, and inserting just the cloned portion as a new compressed inline extent. For now, just return -EINVAL in this case. Note that this never comes up in the more common case of cloning an entire file. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-30Btrfs: Add fallocate support v2Yan Zheng
This patch updates btrfs-progs for fallocate support. fallocate is a little different in Btrfs because we need to tell the COW system that a given preallocated extent doesn't need to be cow'd as long as there are no snapshots of it. This leverages the -o nodatacow checks. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-30Btrfs: update nodatacow code v2Yan Zheng
This patch simplifies the nodatacow checker. If all references were created after the latest snapshot, then we can avoid COW safely. This patch also updates run_delalloc_nocow to do more fine-grained checking. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-29Btrfs: Add root tree pointer transaction idsYan Zheng
This patch adds transaction IDs to root tree pointers. Transaction IDs in tree pointers are compared with the generation numbers in block headers when reading root blocks of trees. This can detect some types of IO errors. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-10Btrfs: Don't call security_inode_mkdir during subvol creationChris Mason
Subvol creation already requires privs, and security_inode_mkdir isn't exported. For now we don't need it. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-09Btrfs: Fix subvolume creation locking rulesChristoph Hellwig
Creating a subvolume is in many ways like a normal VFS ->mkdir, and we really need to play with the VFS topology locking rules. So instead of just creating the snapshot on disk and then later getting rid of confliting aliases do it correctly from the start. This will become especially important once we allow for subvolumes anywhere in the tree, and not just below a hidden root. Note that snapshots will need the same treatment, but do to the delay in creating them we can't do it currently. Chris promised to fix that issue, so I'll wait on that. Signed-off-by: Christoph Hellwig <hch@lst.de>
2008-10-09Btrfs: Remove offset field from struct btrfs_extent_refYan Zheng
The offset field in struct btrfs_extent_ref records the position inside file that file extent is referenced by. In the new back reference system, tree leaves holding references to file extent are recorded explicitly. We can scan these tree leaves very quickly, so the offset field is not required. This patch also makes the back reference system check the objectid when extents are in deleting. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-09Btrfs: Count space allocated to file in bytesYan Zheng
This patch makes btrfs count space allocated to file in bytes instead of 512 byte sectors. Everything else in btrfs uses a byte count instead of sector sizes or blocks sizes, so this fits better. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-09-26Btrfs: extent_map and data=ordered fixes for space balancingZheng Yan
* Add an EXTENT_BOUNDARY state bit to keep the writepage code from merging data extents that are in the process of being relocated. This allows us to do accounting for them properly. * The balancing code relocates data extents indepdent of the underlying inode. The extent_map code was modified to properly account for things moving around (invalidating extent_map caches in the inode). * Don't take the drop_mutex in the create_subvol ioctl. It isn't required. * Fix walking of the ordered extent list to avoid races with sys_unlink * Change the lock ordering rules. Transaction start goes outside the drop_mutex. This allows btrfs_commit_transaction to directly drop the relocation trees. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Full back reference supportZheng Yan
This patch makes the back reference system to explicit record the location of parent node for all types of extents. The location of parent node is placed into the offset field of backref key. Every time a tree block is balanced, the back references for the affected lower level extents are updated. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: trivial sparse fixesChristoph Hellwig
Fix a bunch of trivial sparse complaints. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Fix nodatacow for the new data=ordered modeYan Zheng
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Update clone file ioctlYan Zheng
This patch updates the file clone ioctl for the tree locking and new data ordered code. --- Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Maintain a list of inodes that are delalloc and a way to wait on themChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: fix ioctl-initiated transactions vs wait_current_trans()Sage Weil
Commit 597:466b27332893 (btrfs_start_transaction: wait for commits in progress) breaks the transaction start/stop ioctls by making btrfs_start_transaction conditionally wait for the next transaction to start. If an application artificially is holding a transaction open, things deadlock. This workaround maintains a count of open ioctl-initiated transactions in fs_info, and avoids wait_current_trans() if any are currently open (in start_transaction() and btrfs_throttle()). The start transaction ioctl uses a new btrfs_start_ioctl_transaction() that _does_ call wait_current_trans(), effectively pushing the join/wait decision to the outer ioctl-initiated transaction. This more or less neuters btrfs_throttle() when ioctl-initiated transactions are in use, but that seems like a pretty fundamental consequence of wrapping lots of write()'s in a transaction. Btrfs has no way to tell if the application considers a given operation as part of it's transaction. Obviously, if the transaction start/stop ioctls aren't being used, there is no effect on current behavior. Signed-off-by: Sage Weil <sage@newdream.net> --- ctree.h | 1 + ioctl.c | 12 +++++++++++- transaction.c | 18 +++++++++++++----- transaction.h | 2 ++ 4 files changed, 27 insertions(+), 6 deletions(-) Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Improve and cleanup locking done by walk_down_treeChris Mason
While dropping snapshots, walk_down_tree does most of the work of checking reference counts and limiting tree traversal to just the blocks that we are freeing. It dropped and held the allocation mutex in strange and confusing ways, this commit changes it to only hold the mutex while actually freeing a block. The rest of the checks around reference counts should be safe without the lock because we only allow one process in btrfs_drop_snapshot at a time. Other processes dropping reference counts should not drop it to 1 because their tree roots already have an extra ref on the block. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Null terminate strings passed in from userspaceMark Fasheh
The 'char name[BTRFS_PATH_NAME_MAX]' member of struct btrfs_ioctl_vol_args is passed directly to strlen() after being copied from user. I haven't verified this, but in theory a userspace program could pass in an unterminated string and cause a kernel crash as strlen walks off the end of the array. This patch terminates the ->name string in all btrfs ioctl functions which currently use a 'struct btrfs_ioctl_vol_args'. Since the string is now properly terminated, it's length will never be longer than BTRFS_PATH_NAME_MAX so that error check has been removed. By the way, it might be better overall to just have the ioctl pass an unterminated string + length structure but I didn't bother with that since it'd change the kernel/user interface. Signed-off-by: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Fix a few functions that exit without stopping their transactionJosef Bacik
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Implement new dir index formatJosef Bacik
Signed-off-by: Chris Mason <chris.mason@oracle.com>