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* Btrfs: pass fs_info to btrfs_map_block() instead of mapping_treeStefan Behrens2012-12-12
| | | | | | | | | This is required for the device replace procedure in a later step. Two calling functions also had to be changed to have the fs_info pointer: repair_io_failure() and scrub_setup_recheck_block(). Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: Pass fs_info to btrfs_num_copies() instead of mapping_treeStefan Behrens2012-12-12
| | | | | | | This is required for the device replace procedure in a later step. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: add two more find_device() methodsStefan Behrens2012-12-12
| | | | | | | | | | | | | | The new function btrfs_find_device_missing_or_by_path() will be used for the device replace procedure. This function itself calls the second new function btrfs_find_device_by_path(). Unfortunately, it is not possible to currently make the rest of the code use these functions as well, since all functions that look similar at first view are all a little bit different in what they are doing. But in the future, new code could benefit from these two new functions, and currently, device replace uses them. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: move some common code into a subfunctionStefan Behrens2012-12-12
| | | | | | | | | | Some code to open block devices, to read the superblock and to handle errors was repeated multiple times in 3 places, and the following patch makes use of it as well. This code is now moved into a subfunction. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: cleanup scrub bio and worker wait codeStefan Behrens2012-12-12
| | | | | | | Just move some code into functions to make everything more readable. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: in scrub repair code, simplify alloc error handlingStefan Behrens2012-12-12
| | | | | | | | | | | In the scrub repair code, the code is changed to handle memory allocation errors a little bit smarter. The change is to handle it just like a read error. This simplifies the code and removes a couple of lines of code, since the code to handle read errors is there anyway. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: in scrub repair code, optimize the reading of mirrorsStefan Behrens2012-12-12
| | | | | | | | | | | | In case that disk blocks need to be repaired (rewritten), the current code at first (for simplicity reasons) reads all alternate mirrors in the first step, afterwards selects the best one in a second step. This is now changed to read one alternate mirror after the other and to leave the loop early when a perfect mirror is found. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: make the scrub page array dynamically allocatedStefan Behrens2012-12-12
| | | | | | | | | | | | | | | | With the modified design (in order to support the devive replace procedure) it is necessary to alloc the page array dynamically. The reason is that pages are reused. At first a page is used for the bio to read the data from the filesystem, then the same page is reused for the bio that writes the data to the target disk. Since the read process and the write process are completely decoupled, this requires a new concept of refcounts and get/put functions for pages, and it requires to use newly created pages for each read bio which are freed after the write operation is finished. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: remove the block device pointer from the scrub context structStefan Behrens2012-12-12
| | | | | | | | | | | | | | | | | | | | The block device is removed from the scrub context state structure. The scrub code as it is used for the device replace procedure reads the source data from whereever it is optimal. The source device might even be gone (disconnected, for instance due to a hardware failure). Or the drive can be so faulty so that the device replace procedure tries to avoid access to the faulty source drive as much as possible, and only if all other mirrors are damaged, as a last resort, the source disk is accessed. The modified scrub code operates as if it would handle the source drive and thereby generates an exact copy of the source disk on the target disk, even if the source disk is not present at all. Therefore the block device pointer to the source disk is removed in the scrub context struct and moved into the lower level scope of scrub_bio, fixup and page structures where the block device context is known. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: rename the scrub context structureStefan Behrens2012-12-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The device replace procedure makes use of the scrub code. The scrub code is the most efficient code to read the allocated data of a disk, i.e. it reads sequentially in order to avoid disk head movements, it skips unallocated blocks, it uses read ahead mechanisms, and it contains all the code to detect and repair defects. This commit is a first preparation step to adapt the scrub code to be shareable for the device replace procedure. The block device will be removed from the scrub context state structure in a later step. It used to be the source block device. The scrub code as it is used for the device replace procedure reads the source data from whereever it is optimal. The source device might even be gone (disconnected, for instance due to a hardware failure). Or the drive can be so faulty so that the device replace procedure tries to avoid access to the faulty source drive as much as possible, and only if all other mirrors are damaged, as a last resort, the source disk is accessed. The modified scrub code operates as if it would handle the source drive and thereby generates an exact copy of the source disk on the target disk, even if the source disk is not present at all. Therefore the block device pointer to the source disk is removed in a later patch, and therefore the context structure is renamed (this is the goal of the current patch) to reflect that no source block device scope is there anymore. Summary: This first preparation step consists of a textual substitution of the term "dev" to the term "ctx" whereever the scrub context is used. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: protect devices list with its mutexLiu Bo2012-12-12
| | | | | | | | Since we've kill the bigger one volume_mutex, we need to add devices list mutex back. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: cleanup for btrfs_btree_balance_dirtyLiu Bo2012-12-12
| | | | | | | | | - 'nr' is no more used. - btrfs_btree_balance_dirty() and __btrfs_btree_balance_dirty() can share a bunch of code. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: merge inode_list in __merge_refsAlexander Block2012-12-12
| | | | | | | | | | | When __merge_refs merges two refs, it is also needed to merge the inode_list of both refs. Otherwise we have missed backrefs and memory leaks. This happens for example if two inodes share an extent and both lie in the same leaf and thus also have the same parent. Signed-off-by: Alexander Block <ablock84@googlemail.com> Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: set hole punching time properlyTsutomu Itoh2012-12-12
| | | | | | | | | Even if the hole punching is executed, the modification time of the file is not updated. So, current time is set to inode. Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: Don't trust the superblock label and simply printk("%s") itStefan Behrens2012-12-12
| | | | | | | | | | | | Someone who is root or capable(CAP_SYS_ADMIN) could corrupt the superblock and make Btrfs printk("%s") crash while holding the uuid_mutex since nobody forces a limit on the string. Since the uuid_mutex is significant, the system would be unusable afterwards. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: fix a double free on pending snapshots in error handlingLiu Bo2012-12-12
| | | | | | | | | | | When creating a snapshot, failing to commit a transaction can end up with aborting the transaction, following by doing a cleanup for it, where we'll free all snapshots pending to disk. So we check it and avoid double free on pending snapshots. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: fix a deadlock in aborting transaction due to ENOSPCLiu Bo2012-12-12
| | | | | | | | | | | When committing a transaction, we may bail out of running delayed refs due to ENOSPC, and then abort the current transaction to flip into readonly. But we'll hit a deadlock on ref head's lock since we forget to release its lock and other cleanup stuff. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* fs/btrfs: drop if around WARN_ONJulia Lawall2012-12-12
| | | | | | | | | | | | | | | | | | | Just use WARN_ON rather than an if containing only WARN_ON(1). A simplified version of the semantic patch that makes this transformation is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression e; @@ - if (e) WARN_ON(1); + WARN_ON(e); // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* fs/btrfs: use WARNJulia Lawall2012-12-12
| | | | | | | | | | | | | | | | | | | | | | Use WARN rather than printk followed by WARN_ON(1), for conciseness. A simplified version of the semantic patch that makes this transformation is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression list es; @@ -printk( +WARN(1, es); -WARN_ON(1); // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: fix missing log when BTRFS_INODE_NEEDS_FULL_SYNC is setMiao Xie2012-12-12
| | | | | | | | | If we set BTRFS_INODE_NEEDS_FULL_SYNC, we should log all the extent, but now we forget to take it into account, and set a wrong max key, if so, we will skip the file extent metadata when doing logging. Fix it. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: fix unprotected extent map operation when logging file extentsMiao Xie2012-12-12
| | | | | | | | We forget to protect the modified_extents list, fix it. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: fix wrong file extent lengthMiao Xie2012-12-12
| | | | | | | | | There are two types of the file extent - inline extent and regular extent, When we log file extents, we didn't take inline extent into account, fix it. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: fix missing flush when committing a transactionMiao Xie2012-12-12
| | | | | | | | | | | | | | | | | | | | | | Consider the following case: Task1 Task2 start_transaction commit_transaction check pending snapshots list and the list is empty. add pending snapshot into list skip the delalloc flush end_transaction ... And then the problem that the snapshot is different with the source subvolume happen. This patch fixes the above problem by flush all pending stuffs when all the other tasks end the transaction. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: fix joining the same transaction handler more than 2 timesMiao Xie2012-12-12
| | | | | | | | | | | | | | | | | | | | | If we flush inodes with pending delalloc in a transaction, we may join the same transaction handler more than 2 times. The reason is: Task use_count of trans handle commit_transaction 1 |-> btrfs_start_delalloc_inodes 1 |-> run_delalloc_nocow 1 |-> join_transaction 2 |-> cow_file_range 2 |-> join_transaction 3 In fact, cow_file_range needn't join the transaction again because the caller have joined the transaction, so we fix this problem by this way. Reported-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: cleanup for btrfs_wait_order_rangeLiu Bo2012-12-12
| | | | | | | Variable 'found' is no more used. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: get right arguments for btrfs_wait_ordered_rangeLiu Bo2012-12-12
| | | | | | | btrfs_wait_ordered_range expects for 'len' instead of 'end'. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: do not log extents when we only log new namesLiu Bo2012-12-12
| | | | | | | | | | | | When we log new names, we need to log just enough to recreate the inode during log replay, and there is no need to log extents along with it. This actually fixes a bug revealed by xfstests 241, where it shows that we're logging some extents that have not updated metadata, so we don't get proper EXTENT_DATA items to be copied to log tree. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: don't allow degraded mount if too many devices are missingStefan Behrens2012-12-12
| | | | | | | | | | | | | | | | | | | | | The current behavior is to allow mounting or remounting a filesystem writeable in degraded mode if at least one writeable device is present. The next failed write access to a missing device which is above the tolerance of the configured level of redundancy results in an read-only enforcement. Even without this, the next time barrier_all_devices() is called and more devices are missing than tolerable, the switch to read-only mode takes place. In order to behave predictably and to provide proper feedback to the user at mount time, this patch compares the number of missing devices with the number of devices that are tolerated to be missing according to the configured RAID level. If more devices are missing than tolerated, e.g. if two devices are missing in case of RAID1, only a read-only mount and remount is allowed. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: Fix typo in fs/btrfsMasanari Iida2012-12-12
| | | | | | | Correct spelling typo in btrfs. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: Remove the invalid shrink size check up from btrfs_shrink_dev()jeff.liu2012-12-12
| | | | | | | | | | | | Remove an invalid size check up from btrfs_shrink_dev(). The new size should not larger than the device->total_bytes as it was already verified before coming to here(i.e. new_size < old_size). Remove invalid check up for btrfs_shrink_dev(). Signed-off-by: Jie Liu <jeff.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: make ordered extent be flushed by multi-taskMiao Xie2012-12-11
| | | | | | | | | Though the process of the ordered extents is a bit different with the delalloc inode flush, but we can see it as a subset of the delalloc inode flush, so we also handle them by flush workers. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: make ordered operations be handled by multi-taskMiao Xie2012-12-11
| | | | | | | | The process of the ordered operations is similar to the delalloc inode flush, so we handle them by flush workers. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: make delalloc inodes be flushed by multi-taskMiao Xie2012-12-11
| | | | | | | | | | This patch introduce a new worker pool named "flush_workers", and if we want to force all the inode with pending delalloc to the disks, we can queue those inodes into the work queue of the worker pool, in this way, those inodes will be flushed by multi-task. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: fill the global reserve when unpinning spaceJosef Bacik2012-12-11
| | | | | | | | | | | | | | | | | Dave gave me an image of a very full file system that would abort the transaction because it ran out of space while committing the transaction. This is because we would think there was plenty of room to create a snapshot even though the global reserve was not full. This happens because we calculate the global reserve size before we unpin any space, so after we unpin the space we allow reservations to occur even though we haven't reserved all of the space for our global reserve. Fix this by adding to the global reserve while unpinning in order to make sure we always have enough space to do our work. With this patch we no longer end up with an aborted transaction, we return ENOSPC properly to the person trying to create the snapshot. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: cleanup unused argumentsLiu Bo2012-12-11
| | | | | | | 'disk_key' is not used at all. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: kill unnecessary arguments in del_ptrLiu Bo2012-12-11
| | | | | | | The argument 'tree_mod_log' is not necessary since all of callers enable it. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: reorder tree mod log operations in deleting a pointerLiu Bo2012-12-11
| | | | | | | | Since we don't use MOD_LOG_KEY_REMOVE_WHILE_MOVING to add nritems during rewinding, we should insert a MOD_LOG_KEY_REMOVE operation first. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: MOD_LOG_KEY_REMOVE_WHILE_MOVING never change node's nritemsLiu Bo2012-12-11
| | | | | | | | | | | | | | | | | | | | | | | | Key MOD_LOG_KEY_REMOVE_WHILE_MOVING means that we're doing memmove inside an extent buffer node, and the node's number of items remains unchanged (unless we are inserting a single pointer, but we have MOD_LOG_KEY_ADD for that). So we don't need to increase node's number of items during rewinding, otherwise we may get an node larger than leafsize and cause general protection errors later. Here is the details, - If we do memory move for inserting a single pointer, we need to add node's nritems by one, and we honor MOD_LOG_KEY_ADD for adding. - If we do memory move for deleting a single pointer, we need to decrease node's nritems by one, and we honor MOD_LOG_KEY_REMOVE for deleting. - If we do memory move for balance left/right, we need to decrease node's nritems, and we honor MOD_LOG_KEY_REMOVE for balaning. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: fix unnecessary while loop when search the free space, cacheMiao Xie2012-12-11
| | | | | | | | | | | | | When we find a bitmap free space entry, we may check the previous extent entry covers the offset or not. But if we find this entry is also a bitmap entry, we will continue to check the previous entry of the current one by a while loop. It is unnecessary because it is impossible that the extent entry which is in front of a bitmap entry can cover the offset of the entry after that bitmap entry. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: recheck bio against block device when we map the bioJosef Bacik2012-12-11
| | | | | | | | | | | | | Alex reported a problem where we were writing between chunks on a rbd device. The thing is we do bio_add_page using logical offsets, but the physical offset may be different. So when we map the bio now check to see if the bio is still ok with the physical offset, and if it is not split the bio up and redo the bio_add_page with the physical sector. This fixes the problem for Alex and doesn't affect performance in the normal case. Thanks, Reported-and-tested-by: Alex Elder <elder@inktank.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: improve the noflush reservationMiao Xie2012-12-11
| | | | | | | | | | | | | | | | In some places(such as: evicting inode), we just can not flush the reserved space of delalloc, flushing the delayed directory index and delayed inode is OK, but we don't try to flush those things and just go back when there is no enough space to be reserved. This patch fixes this problem. We defined 3 types of the flush operations: NO_FLUSH, FLUSH_LIMIT and FLUSH_ALL. If we can in the transaction, we should not flush anything, or the deadlock would happen, so use NO_FLUSH. If we flushing the reserved space of delalloc would cause deadlock, use FLUSH_LIMIT. In the other cases, FLUSH_ALL is used, and we will flush all things. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: fix wrong comment in can_overcommit()Miao Xie2012-12-11
| | | | | | | The comment is not coincident with the code. Fix it. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* Btrfs: cleanup duplicated division functionsMiao Xie2012-12-11
| | | | | | | | | div_factor{_fine} has been implemented for two times, cleanup it. And I move them into a independent file named math.h because they are common math functions. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* vfs: fix O_DIRECT read past end of block deviceLinus Torvalds2012-12-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The direct-IO write path already had the i_size checks in mm/filemap.c, but it turns out the read path did not, and removing the block size checks in fs/block_dev.c (commit bbec0270bdd8: "blkdev_max_block: make private to fs/buffer.c") removed the magic "shrink IO to past the end of the device" code there. Fix it by truncating the IO to the size of the block device, like the write path already does. NOTE! I suspect the write path would be *much* better off doing it this way in fs/block_dev.c, rather than hidden deep in mm/filemap.c. The mm/filemap.c code is extremely hard to follow, and has various conditionals on the target being a block device (ie the flag passed in to 'generic_write_checks()', along with a conditional update of the inode timestamp etc). It is also quite possible that we should treat this whole block device size as a "s_maxbytes" issue, and try to make the logic even more generic. However, in the meantime this is the fairly minimal targeted fix. Noted by Milan Broz thanks to a regression test for the cryptsetup reencrypt tool. Reported-and-tested-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: clear to the end of the buffer on partial buffer readsDan Carpenter2012-12-05
| | | | | | | | READ is zero so the "rw & READ" test is always false. The intended test was "((rw & RW_MASK) == READ)". Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: avoid "attempt to access beyond end of device" warningsLinus Torvalds2012-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The block device access simplification that avoided accessing the (racy) block size information (commit bbec0270bdd8: "blkdev_max_block: make private to fs/buffer.c") no longer checks the maximum block size in the block mapping path. That was _almost_ as simple as just removing the code entirely, because the readers and writers all check the size of the device anyway, so under normal circumstances it "just worked". However, the block size may be such that the end of the device may straddle one single buffer_head. At which point we may still want to access the end of the device, but the buffer we use to access it partially extends past the end. The 'bd_set_size()' function intentionally sets the block size to avoid this, but mounting the device - or setting the block size by hand to some other value - can modify that block size. So instead, teach 'submit_bh()' about the special case of the buffer head straddling the end of the device, and turning such an access into a smaller IO access, avoiding the problem. This, btw, also means that unlike before, we can now access the whole device regardless of device block size setting. So now, even if the device size is only 512-byte aligned, we can read and write even the last sector even when having a much bigger block size for accessing the rest of the device. So with this, we could now get rid of the 'bd_set_size()' block size code entirely - resulting in faster IO for the common case - but that would be a separate patch. Reported-and-tested-by: Romain Francoise <romain@orebokech.com> Reporeted-and-tested-by: Meelis Roos <mroos@linux.ee> Reported-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'block-dev'Linus Torvalds2012-12-03
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge 'block-dev' branch. I was going to just mark everything here for stable and leave it to the 3.8 merge window, but having decided on doing another -rc, I migth as well merge it now. This removes the bd_block_size_semaphore semaphore that was added in this release to fix a race condition between block size changes and block IO, and replaces it with atomicity guaratees in fs/buffer.c instead, along with simplifying fs/block-dev.c. This removes more lines than it adds, makes the code generally simpler, and avoids the latency/rt issues that the block size semaphore introduced for mount. I'm not happy with the timing, but it wouldn't be much better doing this during the merge window and then having some delayed back-port of it into stable. * block-dev: blkdev_max_block: make private to fs/buffer.c direct-io: don't read inode->i_blkbits multiple times blockdev: remove bd_block_size_semaphore again fs/buffer.c: make block-size be per-page and protected by the page lock
| * blkdev_max_block: make private to fs/buffer.cLinus Torvalds2012-11-29
| | | | | | | | | | | | | | | | | | | | | | | | We really don't want to look at the block size for the raw block device accesses in fs/block-dev.c, because it may be changing from under us. So get rid of the max_block logic entirely, since the caller should already have done it anyway. That leaves the only user of this function in fs/buffer.c, so move the whole function there and make it static. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * direct-io: don't read inode->i_blkbits multiple timesLinus Torvalds2012-11-29
| | | | | | | | | | | | | | | | | | | | | | | | | | Since directio can work on a raw block device, and the block size of the device can change under it, we need to do the same thing that fs/buffer.c now does: read the block size a single time, using ACCESS_ONCE(). Reading it multiple times can get different results, which will then confuse the code because it actually encodes the i_blksize in relationship to the underlying logical blocksize. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * blockdev: remove bd_block_size_semaphore againLinus Torvalds2012-11-29
| | | | | | | | | | | | | | | | | | | | This reverts the block-device direct access code to the previous unlocked code, now that fs/buffer.c no longer needs external locking. With this, fs/block_dev.c is back to the original version, apart from a whitespace cleanup that I didn't want to revert. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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