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From:   Christoph Hellwig <hch@lst.de>
To:     linux-ext4@vger.kernel.org, viro@zeniv.linux.org.uk
Cc:     jack@suse.cz, tytso@mit.edu, adilger@dilger.ca,
        riteshh@linux.ibm.com, amir73il@gmail.com,
        linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org
Subject: [PATCH 09/11] fs: handle FIEMAP_FLAG_SYNC in fiemap_prep
Date:   Mon, 27 Apr 2020 20:19:55 +0200
Message-Id: <20200427181957.1606257-10-hch@lst.de>
In-Reply-To: <20200427181957.1606257-1-hch@lst.de>
References: <20200427181957.1606257-1-hch@lst.de>
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By moving FIEMAP_FLAG_SYNC handling to fiemap_prep we ensure it is
handled once instead of duplicated, but can still be done under fs locks,
like xfs/iomap intended with its duplicate handling.  Also make sure the
error value of filemap_write_and_wait is propagated to user space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/btrfs/inode.c      |  4 +---
 fs/cifs/smb2ops.c     |  3 +--
 fs/ext4/extents.c     |  2 +-
 fs/f2fs/data.c        |  3 +--
 fs/ioctl.c            | 10 ++++++----
 fs/iomap/fiemap.c     |  8 +-------
 fs/nilfs2/inode.c     |  2 +-
 fs/ocfs2/extent_map.c |  5 +----
 fs/overlayfs/inode.c  |  4 ----
 9 files changed, 13 insertions(+), 28 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 1f1ec361089b3..529ffa5e7b452 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8243,14 +8243,12 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 	return ret;
 }
 
-#define BTRFS_FIEMAP_FLAGS	(FIEMAP_FLAG_SYNC)
-
 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		__u64 start, __u64 len)
 {
 	int	ret;
 
-	ret = fiemap_prep(inode, fieinfo, start, &len, BTRFS_FIEMAP_FLAGS);
+	ret = fiemap_prep(inode, fieinfo, start, &len, 0);
 	if (ret)
 		return ret;
 
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 8a2e94931dc96..32880fca6d8d8 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3408,8 +3408,7 @@ static int smb3_fiemap(struct cifs_tcon *tcon,
 	int i, num, rc, flags, last_blob;
 	u64 next;
 
-	rc = fiemap_prep(cfile->dentry->d_inode, fei, start, &len,
-			FIEMAP_FLAG_SYNC);
+	rc = fiemap_prep(cfile->dentry->d_inode, fei, start, &len, 0);
 	if (rc)
 		rc;
 
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 41f73dea92cac..93574e88f6543 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4908,7 +4908,7 @@ int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
 	}
 
-	error = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC);
+	error = fiemap_prep(inode, fieinfo, start, &len, 0);
 	if (error)
 		return error;
 
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 03faafc591b17..9de7dc476ed16 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1825,8 +1825,7 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 			return ret;
 	}
 
-	ret = fiemap_prep(inode, fieinfo, start, &len,
-			FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR);
+	ret = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_XATTR);
 	if (ret)
 		return ret;
 
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 4d94c20c9596b..ae0d228d18a16 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -162,6 +162,7 @@ int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo,
 {
 	u64 maxbytes = inode->i_sb->s_maxbytes;
 	u32 incompat_flags;
+	int ret = 0;
 
 	if (*len == 0)
 		return -EINVAL;
@@ -174,13 +175,17 @@ int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	if (*len > maxbytes || (maxbytes - *len) < start)
 		*len = maxbytes - start;
 
+	supported_flags |= FIEMAP_FLAG_SYNC;
 	supported_flags &= FIEMAP_FLAGS_COMPAT;
 	incompat_flags = fieinfo->fi_flags & ~supported_flags;
 	if (incompat_flags) {
 		fieinfo->fi_flags = incompat_flags;
 		return -EBADR;
 	}
-	return 0;
+
+	if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
+		ret = filemap_write_and_wait(inode->i_mapping);
+	return ret;
 }
 EXPORT_SYMBOL(fiemap_prep);
 
@@ -209,9 +214,6 @@ static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap)
 		       fieinfo.fi_extents_max * sizeof(struct fiemap_extent)))
 		return -EFAULT;
 
-	if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
-		filemap_write_and_wait(inode->i_mapping);
-
 	error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start,
 			fiemap.fm_length);
 	fiemap.fm_flags = fieinfo.fi_flags;
diff --git a/fs/iomap/fiemap.c b/fs/iomap/fiemap.c
index 5e4e3520424da..fffd9eedfd880 100644
--- a/fs/iomap/fiemap.c
+++ b/fs/iomap/fiemap.c
@@ -75,16 +75,10 @@ int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
 	ctx.fi = fi;
 	ctx.prev.type = IOMAP_HOLE;
 
-	ret = fiemap_prep(inode, fi, start, &len, FIEMAP_FLAG_SYNC);
+	ret = fiemap_prep(inode, fi, start, &len, 0);
 	if (ret)
 		return ret;
 
-	if (fi->fi_flags & FIEMAP_FLAG_SYNC) {
-		ret = filemap_write_and_wait(inode->i_mapping);
-		if (ret)
-			return ret;
-	}
-
 	while (len > 0) {
 		ret = iomap_apply(inode, start, len, IOMAP_REPORT, ops, &ctx,
 				iomap_fiemap_actor);
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 052c2da11e4d7..25b0d368ecdb2 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -1006,7 +1006,7 @@ int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	unsigned int blkbits = inode->i_blkbits;
 	int ret, n;
 
-	ret = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC);
+	ret = fiemap_prep(inode, fieinfo, start, &len, 0);
 	if (ret)
 		return ret;
 
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index 3744179b73fa1..a94852af5510d 100644
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -733,8 +733,6 @@ static int ocfs2_fiemap_inline(struct inode *inode, struct buffer_head *di_bh,
 	return 0;
 }
 
-#define OCFS2_FIEMAP_FLAGS	(FIEMAP_FLAG_SYNC)
-
 int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		 u64 map_start, u64 map_len)
 {
@@ -746,8 +744,7 @@ int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	struct buffer_head *di_bh = NULL;
 	struct ocfs2_extent_rec rec;
 
-	ret = fiemap_prep(inode, fieinfo, map_start, &map_len,
-			OCFS2_FIEMAP_FLAGS);
+	ret = fiemap_prep(inode, fieinfo, map_start, &map_len, 0);
 	if (ret)
 		return ret;
 
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index b5fec34105569..c7cb883c47b86 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -462,10 +462,6 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		return -EOPNOTSUPP;
 
 	old_cred = ovl_override_creds(inode->i_sb);
-
-	if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
-		filemap_write_and_wait(realinode->i_mapping);
-
 	err = realinode->i_op->fiemap(realinode, fieinfo, start, len);
 	revert_creds(old_cred);
 
-- 
2.26.1