From 76341cabbdad65c10a4162e9dfa82a6342afc02f Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Thu, 6 Jul 2017 07:02:22 -0400 Subject: [PATCH] jbd2: don't clear and reset errors after waiting on writeback Resetting this flag is almost certainly racy, and will be problematic with some coming changes. Make filemap_fdatawait_keep_errors return int, but not clear the flag(s). Have jbd2 call it instead of filemap_fdatawait and don't attempt to re-set the error flag if it fails. Reviewed-by: Jan Kara Reviewed-by: Carlos Maiolino Signed-off-by: Jeff Layton --- fs/jbd2/commit.c | 16 ++++------------ include/linux/fs.h | 2 +- mm/filemap.c | 16 ++++++++++++++-- 3 files changed, 19 insertions(+), 15 deletions(-) diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index b6b194ec1b4f..3c1c31321d9b 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -263,18 +263,10 @@ static int journal_finish_inode_data_buffers(journal_t *journal, continue; jinode->i_flags |= JI_COMMIT_RUNNING; spin_unlock(&journal->j_list_lock); - err = filemap_fdatawait(jinode->i_vfs_inode->i_mapping); - if (err) { - /* - * Because AS_EIO is cleared by - * filemap_fdatawait_range(), set it again so - * that user process can get -EIO from fsync(). - */ - mapping_set_error(jinode->i_vfs_inode->i_mapping, -EIO); - - if (!ret) - ret = err; - } + err = filemap_fdatawait_keep_errors( + jinode->i_vfs_inode->i_mapping); + if (!ret) + ret = err; spin_lock(&journal->j_list_lock); jinode->i_flags &= ~JI_COMMIT_RUNNING; smp_mb(); diff --git a/include/linux/fs.h b/include/linux/fs.h index 803e5a9b2654..8ac8df1b3550 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2514,7 +2514,7 @@ extern int write_inode_now(struct inode *, int); extern int filemap_fdatawrite(struct address_space *); extern int filemap_flush(struct address_space *); extern int filemap_fdatawait(struct address_space *); -extern void filemap_fdatawait_keep_errors(struct address_space *); +extern int filemap_fdatawait_keep_errors(struct address_space *mapping); extern int filemap_fdatawait_range(struct address_space *, loff_t lstart, loff_t lend); extern int filemap_write_and_wait(struct address_space *mapping); diff --git a/mm/filemap.c b/mm/filemap.c index 6f1be573a5e6..e5711b2728f4 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -309,6 +309,16 @@ int filemap_check_errors(struct address_space *mapping) } EXPORT_SYMBOL(filemap_check_errors); +static int filemap_check_and_keep_errors(struct address_space *mapping) +{ + /* Check for outstanding write errors */ + if (test_bit(AS_EIO, &mapping->flags)) + return -EIO; + if (test_bit(AS_ENOSPC, &mapping->flags)) + return -ENOSPC; + return 0; +} + /** * __filemap_fdatawrite_range - start writeback on mapping dirty pages in range * @mapping: address space structure to write @@ -453,15 +463,17 @@ EXPORT_SYMBOL(filemap_fdatawait_range); * call sites are system-wide / filesystem-wide data flushers: e.g. sync(2), * fsfreeze(8) */ -void filemap_fdatawait_keep_errors(struct address_space *mapping) +int filemap_fdatawait_keep_errors(struct address_space *mapping) { loff_t i_size = i_size_read(mapping->host); if (i_size == 0) - return; + return 0; __filemap_fdatawait_range(mapping, 0, i_size - 1); + return filemap_check_and_keep_errors(mapping); } +EXPORT_SYMBOL(filemap_fdatawait_keep_errors); /** * filemap_fdatawait - wait for all under-writeback pages to complete