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author | Ryan Ding <ryan.ding@oracle.com> | 2016-03-25 14:20:55 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-25 16:37:42 -0700 |
commit | b46637d59f1160dee5d8e03498e667ab36c2be04 (patch) | |
tree | e01bf53fa84428fa3b86e24245e3640be5dce8ee /fs/ocfs2/aops.c | |
parent | c1ad1e3ca3064b1f0ab5a5185b4732ab9ad8fa24 (diff) | |
download | linux-stable-b46637d59f1160dee5d8e03498e667ab36c2be04.tar.gz linux-stable-b46637d59f1160dee5d8e03498e667ab36c2be04.tar.bz2 linux-stable-b46637d59f1160dee5d8e03498e667ab36c2be04.zip |
ocfs2: use c_new to indicate newly allocated extents
To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock.
There is a problem in ocfs2's direct io implement: if system crashed
after extents allocated, and before data return, we will get a extent
with dirty data on disk. This problem violate the journal=order
semantics, which means meta changes take effect after data written to
disk. To resolve this issue, direct write can use the UNWRITTEN flag to
describe a extent during direct data writeback. The direct write
procedure should act in the following order:
phase 1: alloc extent with UNWRITTEN flag
phase 2: submit direct data to disk, add zero page to page cache
phase 3: clear UNWRITTEN flag when data has been written to disk
This patch is to change the 'c_unwritten' member of
ocfs2_write_cluster_desc to 'c_clear_unwritten'. Means whether to clear
the unwritten flag. It do not care if a extent is allocated or not.
And use 'c_new' to specify a newly allocated extent. So the direct io
procedure can use c_clear_unwritten to control the UNWRITTEN bit on
extent.
Signed-off-by: Ryan Ding <ryan.ding@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ocfs2/aops.c')
-rw-r--r-- | fs/ocfs2/aops.c | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index 69d7392f56d8..516ea896f13c 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -1212,7 +1212,7 @@ struct ocfs2_write_cluster_desc { * filled. */ unsigned c_new; - unsigned c_unwritten; + unsigned c_clear_unwritten; unsigned c_needs_zero; }; @@ -1588,19 +1588,19 @@ out: * Prepare a single cluster for write one cluster into the file. */ static int ocfs2_write_cluster(struct address_space *mapping, - u32 phys, unsigned int unwritten, + u32 phys, unsigned int new, + unsigned int clear_unwritten, unsigned int should_zero, struct ocfs2_alloc_context *data_ac, struct ocfs2_alloc_context *meta_ac, struct ocfs2_write_ctxt *wc, u32 cpos, loff_t user_pos, unsigned user_len) { - int ret, i, new; + int ret, i; u64 v_blkno, p_blkno; struct inode *inode = mapping->host; struct ocfs2_extent_tree et; - new = phys == 0 ? 1 : 0; if (new) { u32 tmp_pos; @@ -1610,9 +1610,9 @@ static int ocfs2_write_cluster(struct address_space *mapping, */ tmp_pos = cpos; ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode, - &tmp_pos, 1, 0, wc->w_di_bh, - wc->w_handle, data_ac, - meta_ac, NULL); + &tmp_pos, 1, !clear_unwritten, + wc->w_di_bh, wc->w_handle, + data_ac, meta_ac, NULL); /* * This shouldn't happen because we must have already * calculated the correct meta data allocation required. The @@ -1629,7 +1629,7 @@ static int ocfs2_write_cluster(struct address_space *mapping, mlog_errno(ret); goto out; } - } else if (unwritten) { + } else if (clear_unwritten) { ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), wc->w_di_bh); ret = ocfs2_mark_extent_written(inode, &et, @@ -1712,7 +1712,8 @@ static int ocfs2_write_cluster_by_desc(struct address_space *mapping, local_len = osb->s_clustersize - cluster_off; ret = ocfs2_write_cluster(mapping, desc->c_phys, - desc->c_unwritten, + desc->c_new, + desc->c_clear_unwritten, desc->c_needs_zero, data_ac, meta_ac, wc, desc->c_cpos, pos, local_len); @@ -1857,11 +1858,12 @@ static int ocfs2_populate_write_desc(struct inode *inode, if (phys == 0) { desc->c_new = 1; desc->c_needs_zero = 1; + desc->c_clear_unwritten = 1; *clusters_to_alloc = *clusters_to_alloc + 1; } if (ext_flags & OCFS2_EXT_UNWRITTEN) { - desc->c_unwritten = 1; + desc->c_clear_unwritten = 1; desc->c_needs_zero = 1; } |