fs: handle FIEMAP_FLAG_SYNC in fiemap_prep
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>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Link: https://lore.kernel.org/r/20200523073016.2944131-8-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 56bbf02..b16e962 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -166,6 +166,7 @@ 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;
@@ -178,13 +179,17 @@ 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);
@@ -213,9 +218,6 @@ 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;
