BMC/Intel-BMC/linux.git/fs/f2fs/gc.c, branch dev-4.4

f2fs: relocate the tracepoint for background_gc

2015-10-13T17:02:01+00:00

Once f2fs_gc is done, wait_ms is changed once more. So, its tracepoint would be located after it. Reported-by: He YunLei Signed-off-by: Jaegeuk Kim

f2fs crypto: fix racing of accessing encrypted page among

2015-10-13T16:52:34+00:00

different competitors Since we use different page cache (normally inode's page cache for R/W and meta inode's page cache for GC) to cache the same physical block which is belong to an encrypted inode. Writeback of these two page cache should be exclusive, but now we didn't handle writeback state well, so there may be potential racing problem: a) kworker: f2fs_gc: - f2fs_write_data_pages - f2fs_write_data_page - do_write_data_page - write_data_page - f2fs_submit_page_mbio (page#1 in inode's page cache was queued in f2fs bio cache, and be ready to write to new blkaddr) - gc_data_segment - move_encrypted_block - pagecache_get_page (page#2 in meta inode's page cache was cached with the invalid datas of physical block located in new blkaddr) - f2fs_submit_page_mbio (page#1 was submitted, later, page#2 with invalid data will be submitted) b) f2fs_gc: - gc_data_segment - move_encrypted_block - f2fs_submit_page_mbio (page#1 in meta inode's page cache was queued in f2fs bio cache, and be ready to write to new blkaddr) user thread: - f2fs_write_begin - f2fs_submit_page_bio (we submit the request to block layer to update page#2 in inode's page cache with physical block located in new blkaddr, so here we may read gabbage data from new blkaddr since GC hasn't writebacked the page#1 yet) This patch fixes above potential racing problem for encrypted inode. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: support lower priority asynchronous readahead in ra_meta_pages

2015-10-12T21:03:15+00:00

Now, we use ra_meta_pages to reads continuous physical blocks as much as possible to improve performance of following reads. However, ra_meta_pages uses a synchronous readahead approach by submitting bio with READ, as READ is with high priority, it can not be used in the case of preloading blocks, and it's not sure when these RAed pages will be used. This patch supports asynchronous readahead in ra_meta_pages by tagging bio with READA flag in order to allow preloading. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: set GFP_NOFS for grab_cache_page

2015-10-12T20:38:03+00:00

For normal inodes, their pages are allocated with __GFP_FS, which can cause filesystem calls when reclaiming memory. This can incur a dead lock condition accordingly. So, this patch addresses this problem by introducing f2fs_grab_cache_page(.., bool for_write), which calls grab_cache_page_write_begin() with AOP_FLAG_NOFS. Signed-off-by: Jaegeuk Kim

f2fs: add a tracepoint for background gc

2015-10-09T23:20:57+00:00

This patch introduces a tracepoint to monitor background gc behaviors. Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: introduce background_gc=sync mount option

2015-10-09T23:20:57+00:00

This patch introduce background_gc=sync enabling synchronous cleaning in background. Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: support synchronous gc in ioctl

2015-10-09T23:20:56+00:00

This patch drops in batches gc triggered through ioctl, since user can easily control the gc by designing the loop around the ->ioctl. We support synchronous gc by forcing using FG_GC in f2fs_gc, so with it, user can make sure that in this round all blocks gced were persistent in the device until ioctl returned. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: skip searching dirty map if dirty segment is not exist

2015-10-09T23:20:56+00:00

When searching victim during gc, if there are no dirty segments in filesystem, we will still take the time to search the whole dirty segment map, it's not needed, it's better to skip in this condition. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: fix to avoid redundant searching in dirty map during gc

2015-10-09T23:20:55+00:00

When doing gc, we search a victim in dirty map, starting from position of last victim, we will reset the current searching position until we touch the end of dirty map, and then search the whole diryt map. So sometimes we will search the range [victim, last] twice, it's redundant, this patch avoids this issue. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: should get a victim from retrials

2015-10-09T23:20:55+00:00

If we do not call get_victim first, we cannot get a new victim for retrial path. Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim