summaryrefslogtreecommitdiffstats
path: root/fs
Commit message (Collapse)AuthorAgeFilesLines
* btrfs: add helper to initialize the non-bio part of btrfs_io_bioDavid Sterba2017-06-191-16/+14
| | | | | | | | | | | We use btrfs_bioset for bios and ask to allocate the entire size of btrfs_io_bio from btrfs bio_alloc_bioset. The member 'bio' is initialized but the bytes from 0 to offset of 'bio' are left uninitialized. Although we initialize some of the members in our helpers, we should initialize the whole structures. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: document mandatory order of bio in btrfs_io_bioDavid Sterba2017-06-191-0/+4
| | | | Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: skip checksum verification if IO error occursLiu Bo2017-06-191-6/+8
| | | | | | | | | | | | | | Currently dio read also goes to verify checksum if -EIO has been returned, although it usually fails on checksum, it's not necessary at all, we could directly check if there is another copy to read. And with this, the behavior of dio read is now consistent with that of buffered read. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ use bool for uptodate ] Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: tolerate errors if we have retried successfullyLiu Bo2017-06-191-1/+4
| | | | | | | | | | | | | | | | | | | | | | With raid1 profile, dio read isn't tolerating IO errors if read length is less than the stripe length (64K). Our bio didn't get split in btrfs_submit_direct_hook() if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED) is true and that happens when the read length is less than 64k. In this case, if the underlying device returns error somehow, bio->bi_error has recorded that error. If we could recover the correct data from another copy in profile raid1/10/5/6, with btrfs_subio_endio_read() returning 0, bio would have the correct data in its vector, but bio->bi_error is not updated accordingly so that the following dio_end_io(dio_bio, bio->bi_error) makes directIO think this read has failed. This fixes the problem by setting bio's error to 0 if a good copy has been found. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: pass bytes to btrfs_bio_allocDavid Sterba2017-06-193-8/+8
| | | | | | | | Most callers of btrfs_bio_alloc convert from bytes to sectors. Hide that in the helper and simplify the logic in the callsers. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: opencode trivial compressed_bio_alloc, simplify error handlingDavid Sterba2017-06-191-19/+4
| | | | | | | | | compressed_bio_alloc is now a trivial wrapper around btrfs_bio_alloc, no point keeping it. The error handling can be simplified, as we know btrfs_bio_alloc will never fail. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: remove redundant parameters from btrfs_bio_allocDavid Sterba2017-06-193-10/+5
| | | | | | | | | | All callers pass gfp_flags=GFP_NOFS and nr_vecs=BIO_MAX_PAGES. submit_extent_page adds __GFP_HIGH that does not make a difference in our case as it allows access to memory reserves but otherwise does not change the constraints. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: sink gfp parameter to btrfs_bio_cloneDavid Sterba2017-06-194-5/+5
| | | | | | | All callers pass GFP_NOFS. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: btrfs_io_bio_alloc never fails, skip error handlingDavid Sterba2017-06-195-41/+0
| | | | | | | | Update direct callers of btrfs_io_bio_alloc that do error handling, that we can now remove. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: btrfs_bio_clone never fails, skip error handlingDavid Sterba2017-06-192-7/+2
| | | | | | | | Update direct callers of btrfs_bio_clone that do error handling, that we can now remove. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: btrfs_bio_alloc never fails, skip error handlingDavid Sterba2017-06-191-3/+0
| | | | | | | | Update direct callers of btrfs_bio_alloc that do error handling, that we can now remove. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: bioset allocations will never fail, adapt our helpersDavid Sterba2017-06-191-32/+20
| | | | | | | | | | | | Christoph pointed out that bio allocations backed by a bioset will never fail. As we always use a bioset for all bio allocations, we can skip the error handling. This patch adjusts our low-level helpers, the cascaded changes to all callers will come next. CC: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: switch to kvmalloc and GFP_KERNEL in lzo/zlib alloc_workspaceDavid Sterba2017-06-192-10/+10
| | | | | | | | | | | | | The compression workspace buffers are larger than a page so we use vmalloc, unconditionally. This is not always necessary as there might be contiguous memory available. Let's use the kvmalloc helpers that will try kmalloc first and fallback to vmalloc. For that they require GFP_KERNEL flags. As we now have the alloc_workspace calls protected by memalloc_nofs in the critical contexts, we can safely use GFP_KERNEL. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: switch kmallocs to GFP_KERNEL in lzo/zlib alloc_workspaceDavid Sterba2017-06-192-3/+3
| | | | | | | | As alloc_workspace is now protected by memalloc_nofs where needed, we can switch the kmalloc to use GFP_KERNEL. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: add memalloc_nofs protections around alloc_workspace callbackDavid Sterba2017-06-191-0/+10
| | | | | | | | | | | | | | The workspaces are preallocated at the beginning where we can safely use GFP_KERNEL, but in some cases the find_workspace might reach the allocation again, now in a more restricted context when the bios or pages are being compressed. To avoid potential lockup when alloc_workspace -> vmalloc would silently use the GFP_KERNEL, add the memalloc_nofs helpers around the critical call site. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: adjust includes after vmalloc removalDavid Sterba2017-06-191-1/+1
| | | | | | | As we don't use vmalloc/vzalloc/vfree directly in ctree.c, we can now use the proper header that defines kvmalloc. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: use GFP_KERNEL in init_ipathDavid Sterba2017-06-192-7/+7
| | | | | | | | | Now that init_ipath is called either from a safe context or with memalloc_nofs protection, we can switch to GFP_KERNEL allocations in init_path and init_data_container. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: scrub: add memalloc_nofs protection around init_ipathDavid Sterba2017-06-191-0/+9
| | | | | | | | | | | | | | | init_ipath is called from a safe ioctl context and from scrub when printing an error. The protection is added for three reasons: * init_data_container calls vmalloc and this does not work as expected in the GFP_NOFS context, so this silently does GFP_KERNEL and might deadlock in some cases * keep the context constraint of GFP_NOFS, used by scrub * we want to use GFP_KERNEL unconditionally inside init_ipath or its callees Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: send: use kvmalloc in iterate_dir_itemDavid Sterba2017-06-191-1/+1
| | | | | | | | | We use a growing buffer for xattrs larger than a page size, at some point vmalloc is unconditionally used for larger buffers. We can still try to avoid it using the kvmalloc helper. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: replace opencoded kvzalloc with the helperDavid Sterba2017-06-193-20/+11
| | | | | | | The logic of kmalloc and vmalloc fallback is opencoded in several places, we can now use the existing helper. Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: lzo: compressed data size must be less then input sizeTimofey Titovets2017-06-191-1/+3
| | | | | | | | | | | Logic already skips if compression makes data bigger, let's sync lzo with zlib and also return error if compressed size is equal to input size. Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: simplify code with bio_io_errorGuoqing Jiang2017-06-191-2/+1
| | | | | | | | | | bio_io_error was introduced in the commit 4246a0b63bd8f56a1469b ("block: add a bi_error field to struct bio"), so use it to simplify code. Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: use memalloc_nofs and kvzalloc() for free space tree bitmapsOmar Sandoval2017-06-191-13/+13
| | | | | | | | | | | First, instead of open-coding the vmalloc() fallback, use the new kvzalloc() helper. Second, use memalloc_nofs_{save,restore}() instead of GFP_NOFS, as vmalloc() uses some GFP_KERNEL allocations internally which could lead to deadlocks. Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: use generic slab for for btrfs_transactionDavid Sterba2017-06-194-18/+4
| | | | | | | | | | | | | | | | | | | Observing the number of slab objects of btrfs_transaction, there's just one active on an almost quiescent filesystem, and the number of objects goes to about ten when sync is in progress. Then the nubmer goes down to 1. This matches the expectations of the transaction lifetime. For such use the separate slab cache is not justified, as we do not reuse objects frequently. For the shortlived transaction, the generic slab (size 512) should be ok. We can optimistically expect that the 512 slabs are not all used (fragmentation) and there are free slots to take when we do the allocation, compared to potentially allocating a whole new page for the separate slab. We'll lose the stats about the object use, which could be added later if we really need them. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: scrub: embed scrub_wr_ctx into scrub contextDavid Sterba2017-06-191-54/+49
| | | | | | | | The structure scrub_wr_ctx is not used anywhere just the scrub context, we can move the members there. The tgtdev is renamed so it's more clear that it belongs to the "wr" part. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: scrub: use fs_info::sectorsize and drop it from scrub contextDavid Sterba2017-06-191-14/+10
| | | | | | | | As we now have the node/block sizes in fs_info, we can use them and can drop the local copies. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: add statx supportYonghong Song2017-06-191-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Return enhanced file attributes from the btrfs, including: (1). inode creation time as stx_btime, and (2). Certain BTRFS_INODE_xxx flags are mapped to stx_attributes flags. Example output: [root@localhost ~]# cat t.sh touch t chattr +aic t ~/linux/samples/statx/test-statx t chattr -aic t touch t echo "========================================" ~/linux/samples/statx/test-statx t /bin/rm t [root@localhost ~]# ./t.sh statx(t) = 0 results=fff Size: 0 Blocks: 0 IO Block: 4096 regular file Device: 00:1c Inode: 63962 Links: 1 Access: (0644/-rw-r--r--) Uid: 0 Gid: 0 Access: 2017-05-11 16:03:13.999856591-0700 Modify: 2017-05-11 16:03:13.999856591-0700 Change: 2017-05-11 16:03:14.000856663-0700 Birth: 2017-05-11 16:03:13.999856591-0700 Attributes: 0000000000000034 (........ ........ ........ ........ ........ ........ ........ .-ai.c..) ======================================== statx(t) = 0 results=fff Size: 0 Blocks: 0 IO Block: 4096 regular file Device: 00:1c Inode: 63962 Links: 1 Access: (0644/-rw-r--r--) Uid: 0 Gid: 0 Access: 2017-05-11 16:03:14.006857097-0700 Modify: 2017-05-11 16:03:14.006857097-0700 Change: 2017-05-11 16:03:14.006857097-0700 Birth: 2017-05-11 16:03:13.999856591-0700 Attributes: 0000000000000000 (........ ........ ........ ........ ........ ........ ........ .---.-..) [root@localhost ~]# Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: lzo: fix typo in error message after failed deflateTimofey Titovets2017-06-191-1/+1
| | | | | | | Fix copy paste typo in debug message for lzo.c, lzo is not deflate. Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: btrfs_wait_tree_block_writeback can be void returnJeff Layton2017-06-192-4/+4
| | | | | | | | | | | | | | | | | | | Nothing checks its return value. Is it safe to skip checking return value of btrfs_wait_tree_block_writeback? Liu Bo: I think yes, it's used in walk_log_tree which is called in two places, free_log_tree and log replay. For free_log_tree, it waits for any running writeback of the extent buffer under freeing to finish in case we need to access the eb pointer from page->private, and it's OK to not check the return value, while for log replay, it's doesn't wait because wc->wait is not set. So neither cares about the writeback error. Signed-off-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> [ added more explanation to changelog, from Liu Bo ] Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: remove __BTRFS_LEAF_DATA_SIZENikolay Borisov2017-06-191-6/+3
| | | | | | | | __BTRFS_LAF_DATA_SIZE is used only by BTRFS_LEAF_DATA_SIZE. Make the latter subsume the former. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: rename btrfs_leaf_data to BTRFS_LEAF_DATA_OFFSETNikolay Borisov2017-06-193-27/+25
| | | | | | | | | | | | | | Commit 5f39d397dfbe ("Btrfs: Create extent_buffer interface for large blocksizes") refactored btrfs_leaf_data function to take extent_buffer rather than struct btrfs_leaf. However, as it turns out the parameter being passed is never used. Furthermore this function no longer returns the leaf data but rather the offset to it. So rename the function to BTRFS_LEAF_DATA_OFFSET to make it consistent with other BTRFS_LEAF_* helpers and turn it into a macro. Signed-off-by: Nikolay Borisov <nborisov@suse.com> [ removed () from the macro ] Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: reduce arguments for decompress_bio opsAnand Jain2017-06-194-57/+54
| | | | | | | | struct compressed_bio pointer can be used instead. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: btrfs_decompress_bio() could accept compressed_bio insteadAnand Jain2017-06-191-14/+9
| | | | | | | | | | | | Instead of sending each argument of struct compressed_bio, send the compressed_bio itself. Also by having struct compressed_bio in btrfs_decompress_bio() it would help tracing. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Refactor update_space_infoNikolay Borisov2017-06-191-40/+18
| | | | | | | | | | | | Following the factoring out of the creation code udpate_space_info can only be called for already-existing space_info structs. As such it cannot fail. Remove superfluous error handling and make the function return void. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Separate space_info create/updateNikolay Borisov2017-06-191-66/+66
| | | | | | | | | | | | | | | | | | | | | Currently the struct space_info creation code is intermixed in the udpate_space_info function. There are well-defined points at which the we actually want to create brand-new space_info structs (e.g. during mount of the filesystem as well as sometimes when adding/initialising new chunks). In such cases update_space_info is called with 0 as the bytes parameter. All of this makes for spaghetti code. Fix it by factoring out the creation code in a separate create_space_info structure. This also allows to simplify the internals. Also remove BUG_ON from do_alloc_chunk since the callers handle errors. Furthermore it will make the update_space_info function not fail, allowing us to remove error handling in callers. This will come in a follow up patch. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: let btrfs_print_leaf print more about block groupLiu Bo2017-06-191-2/+5
| | | | | | | | | This adds chunk_objectid and flags, with flags we can recognize whether the block group is about data or metadata. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: skip commit transaction if we don't have enough pinned bytesLiu Bo2017-06-191-1/+1
| | | | | | | | | | | | | | | | | We commit transaction in order to reclaim space from pinned bytes because it could process delayed refs, and in may_commit_transaction(), we check first if pinned bytes are enough for the required space, we then check if that plus bytes reserved for delayed insert are enough for the required space. This changes the code to the above logic. Fixes: b150a4f10d87 ("Btrfs: use a percpu to keep track of possibly pinned bytes") Tested-by: Nikolay Borisov <nborisov@suse.com> Reported-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: scrub: simplify cleanup of wr_ctx in scrub_free_ctxDavid Sterba2017-06-191-5/+1
| | | | | | | | We don't need to take the mutex and zero out wr_cur_bio, as this is called after the scrub finished. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: scrub: inline helper scrub_free_wr_ctxDavid Sterba2017-06-191-10/+4
| | | | | | | | The helper scrub_free_wr_ctx is used only once and fits into scrub_free_ctx as it continues sctx shutdown, no need to keep it separate. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: scrub: inline helper scrub_setup_wr_ctxDavid Sterba2017-06-191-27/+9
| | | | | | | | The helper scrub_setup_wr_ctx is used only once and fits into scrub_setup_ctx as it continues intialization, no need to keep it separate. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: remove root usage from can_overcommitJeff Mahoney2017-06-191-36/+46
| | | | | | | | | | | | | | | | | | can_overcommit using the root to determine the allocation profile is the only use of a root in the call graph below reserve_metadata_bytes. It turns out that we only need to know whether the allocation is for the chunk root or not -- and we can pass that around as a bool instead. This allows us to pull root usage out of the reservation path all the way up to reserve_metadata_bytes itself, which uses it only to compare against fs_info->chunk_root to set the bool. In turn, this eliminates a bunch of races where we use a particular root too early in the mount process. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: cleanup root usage by btrfs_get_alloc_profileJeff Mahoney2017-06-195-15/+28
| | | | | | | | | | | | | | There are two places where we don't already know what kind of alloc profile we need before calling btrfs_get_alloc_profile, but we need access to a root everywhere we call it. This patch adds helpers for btrfs_{data,metadata,system}_alloc_profile() and relegates btrfs_system_alloc_profile to a static for use in those two cases. The next patch will eliminate one of those. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: fix bool type in btrfs_page_exists_in_rangeDavid Sterba2017-06-191-1/+1
| | | | | | We use only a simple bool indicator, int is not a problem here. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: remove unused member list from btrfs_end_io_wqDavid Sterba2017-06-191-1/+0
| | | | | | | | The end io work queue items have been tracked by the work queues since "Btrfs: Add async worker threads for pre and post IO checksumming" (8b7128429235d9bd72cfd5e) (2008). Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: remove unused members dir_path from recorded_refDavid Sterba2017-06-191-8/+0
| | | | | | The two members do not seem to be used since the initial commit. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: remove unused member list from async_submit_bioDavid Sterba2017-06-191-1/+0
| | | | | | | | The list used to track checksums in the early version (2.6.29), but I was able not pinpoint the commit that stopped using it. Everything apparently works without it for a long time. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: remove unused member err from reada_extentDavid Sterba2017-06-191-1/+0
| | | | | | | Seems to be unused since the initial commit, we ignore readahead errors anyway, the full read will handle that if necessary. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Remove unnecessary branching in free-space-tree.cSahil Kang2017-06-191-10/+2
| | | | | | | | | | | | | | | | Both btrfs_create_free_space_tree and btrfs_clear_free_space_tree contain: if (ret) return ret; return 0; The if statement is only false when ret equals zero, and since we return zero in such cases, we can safely remove the branching. Signed-off-by: Sahil Kang <sahil.kang@asilaycomputing.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: hardcode GFP_NOFS for btrfs_bio_clone_partialLiu Bo2017-06-193-6/+4
| | | | | | | | We only pass GFP_NOFS to btrfs_bio_clone_partial, so lets hardcode it. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: work around maybe-uninitialized warningArnd Bergmann2017-06-191-2/+2
| | | | | | | | | | | | | | | | | | | | | A rewrite of btrfs_submit_direct_hook appears to have introduced a warning: fs/btrfs/inode.c: In function 'btrfs_submit_direct_hook': fs/btrfs/inode.c:8467:14: error: 'bio' may be used uninitialized in this function [-Werror=maybe-uninitialized] Where the 'bio' variable was previously initialized unconditionally, it is now set in the "while (submit_len > 0)" loop that would never execute if submit_len is zero. Assuming this cannot happen in practice, we can avoid the warning by simply replacing the while{} loop with a do{}while() loop so the compiler knows that it will always be entered at least once. Fixes changes introduced in "Btrfs: use bio_clone_bioset_partial to simplify DIO submit". Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Sterba <dsterba@suse.com>
OpenPOWER on IntegriCloud