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Date: Mon, 12 Jun 2017 08:23:14 -0400
From: Jeff Layton <jlayton@...hat.com>
To: Andrew Morton <akpm@...ux-foundation.org>,
Al Viro <viro@...IV.linux.org.uk>, Jan Kara <jack@...e.cz>,
tytso@....edu, axboe@...nel.dk, mawilcox@...rosoft.com,
ross.zwisler@...ux.intel.com, corbet@....net,
Chris Mason <clm@...com>, Josef Bacik <jbacik@...com>,
David Sterba <dsterba@...e.com>,
"Darrick J . Wong" <darrick.wong@...cle.com>
Cc: linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
linux-ext4@...r.kernel.org, linux-xfs@...r.kernel.org,
linux-btrfs@...r.kernel.org, linux-block@...r.kernel.org
Subject: [PATCH v6 18/20] ext4: use errseq_t based error handling for reporting data writeback errors
Add the FS_WB_ERRSEQ flag to indicate to other subsystems that errseq_t
based error reporting for data writeback is in effect, and to opt-in to
reporting those errors in call_fsync.
ext4 uses the blockdev mapping for tracking metadata stored in the
pagecache. Sample its wb_err when opening a file and store that in
the f_md_wb_err field. Ensure that we check and advance the metadata
before returning in fsync.
Note that because metadata writeback errors are only tracked on a
per-device level, this does mean that we'll end up reporting an error on
all open file descriptors on this fs when there is a metadata writeback
failure. That's not ideal, but we can possibly improve upon it in the
future.
ext4 also has several calls to filemap_fdatawait and
filemap_write_and_wait. Those will also be changed in a later patch to
versions that use errseq_t based reporting.
Signed-off-by: Jeff Layton <jlayton@...hat.com>
---
fs/ext4/dir.c | 8 ++++++--
fs/ext4/file.c | 5 ++++-
fs/ext4/fsync.c | 23 +++++++++++++++++++----
fs/ext4/super.c | 6 +++---
4 files changed, 32 insertions(+), 10 deletions(-)
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index e8b365000d73..6bbb19510f74 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -611,9 +611,13 @@ static int ext4_dx_readdir(struct file *file, struct dir_context *ctx)
static int ext4_dir_open(struct inode * inode, struct file * filp)
{
+ int ret = 0;
+
if (ext4_encrypted_inode(inode))
- return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
- return 0;
+ ret = fscrypt_get_encryption_info(inode) ? -EACCES : 0;
+ if (!ret)
+ filp->f_md_wb_err = filemap_sample_wb_err(inode->i_sb->s_bdev->bd_inode->i_mapping);
+ return ret;
}
static int ext4_release_dir(struct inode *inode, struct file *filp)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 02ce7e7bbdf5..6e505269132c 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -435,7 +435,10 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
if (ret < 0)
return ret;
}
- return dquot_file_open(inode, filp);
+ ret = dquot_file_open(inode, filp);
+ if (!ret)
+ filp->f_md_wb_err = filemap_sample_wb_err(sb->s_bdev->bd_inode->i_mapping);
+ return ret;
}
/*
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 9d549608fd30..09e28b7fd3f6 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -100,8 +100,10 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
tid_t commit_tid;
bool needs_barrier = false;
- if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
- return -EIO;
+ if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) {
+ ret = -EIO;
+ goto out;
+ }
J_ASSERT(ext4_journal_current_handle() == NULL);
@@ -126,7 +128,8 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
if (ret)
- return ret;
+ goto out;
+
/*
* data=writeback,ordered:
* The caller's filemap_fdatawrite()/wait will sync the data.
@@ -152,12 +155,24 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
needs_barrier = true;
ret = jbd2_complete_transaction(journal, commit_tid);
if (needs_barrier) {
- issue_flush:
+issue_flush:
err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
if (!ret)
ret = err;
}
out:
+ /*
+ * Was there a metadata writeback error since last fsync?
+ *
+ * FIXME: ext4 tracks metadata with a whole-block device mapping. So,
+ * if there is any sort of metadata writeback error, we'll report an
+ * error on all open fds, even ones not associated with the inode
+ */
+ err = filemap_report_md_wb_err(file,
+ inode->i_sb->s_bdev->bd_inode->i_mapping);
+ if (!ret)
+ ret = err;
+
trace_ext4_sync_file_exit(inode, ret);
return ret;
}
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index d37c81f327e7..e98791ebee6f 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -119,7 +119,7 @@ static struct file_system_type ext2_fs_type = {
.name = "ext2",
.mount = ext4_mount,
.kill_sb = kill_block_super,
- .fs_flags = FS_REQUIRES_DEV,
+ .fs_flags = FS_REQUIRES_DEV|FS_WB_ERRSEQ,
};
MODULE_ALIAS_FS("ext2");
MODULE_ALIAS("ext2");
@@ -134,7 +134,7 @@ static struct file_system_type ext3_fs_type = {
.name = "ext3",
.mount = ext4_mount,
.kill_sb = kill_block_super,
- .fs_flags = FS_REQUIRES_DEV,
+ .fs_flags = FS_REQUIRES_DEV|FS_WB_ERRSEQ,
};
MODULE_ALIAS_FS("ext3");
MODULE_ALIAS("ext3");
@@ -5689,7 +5689,7 @@ static struct file_system_type ext4_fs_type = {
.name = "ext4",
.mount = ext4_mount,
.kill_sb = kill_block_super,
- .fs_flags = FS_REQUIRES_DEV,
+ .fs_flags = FS_REQUIRES_DEV|FS_WB_ERRSEQ,
};
MODULE_ALIAS_FS("ext4");
--
2.13.0
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