On Fri, Oct 05, 2018 at 03:28:09PM +1000, Dave Chinner wrote: > On Thu, Oct 04, 2018 at 05:44:47PM -0700, Darrick J. Wong wrote: > > From: Darrick J. Wong <[email protected]> > > > > Refactor all the reflink preparation steps into a separate helper that > > we'll use to land all the upcoming fixes for insufficient input checks. > > If I've read the patch right, this also changes the location of the > page cache truncation, right? i.e. it now happens in the > xfs_reflink_remap_prep() function instead of after the remap? I > think the commit message needs to mention that because it's a fix to > incorrect behaviour....
Right. Sorry I forgot to put that in the changelog. > I've added: > > -- > This rework also moves the invalidation of the destination range to > the prep function so that it is done before the range is remapped. > This ensures that nobody can access the data in range being remapped > until the remap is complete. > -- > > Sound OK? Yep. --D > Otherwise this looks fine. > > Reviewed-by: Dave Chinner <[email protected]> > > -Dave. > > > > > Signed-off-by: Darrick J. Wong <[email protected]> > > --- > > fs/xfs/xfs_reflink.c | 96 > > +++++++++++++++++++++++++++++++++++++------------- > > 1 file changed, 71 insertions(+), 25 deletions(-) > > > > > > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c > > index 38f405415b88..80ca9b6793cd 100644 > > --- a/fs/xfs/xfs_reflink.c > > +++ b/fs/xfs/xfs_reflink.c > > @@ -1195,11 +1195,33 @@ xfs_iolock_two_inodes_and_break_layout( > > return 0; > > } > > > > +/* Unlock both inodes after they've been prepped for a range clone. */ > > +STATIC void > > +xfs_reflink_remap_unlock( > > + struct file *file_in, > > + struct file *file_out) > > +{ > > + struct inode *inode_in = file_inode(file_in); > > + struct xfs_inode *src = XFS_I(inode_in); > > + struct inode *inode_out = file_inode(file_out); > > + struct xfs_inode *dest = XFS_I(inode_out); > > + bool same_inode = (inode_in == inode_out); > > + > > + xfs_iunlock(dest, XFS_MMAPLOCK_EXCL); > > + if (!same_inode) > > + xfs_iunlock(src, XFS_MMAPLOCK_SHARED); > > + inode_unlock(inode_out); > > + if (!same_inode) > > + inode_unlock_shared(inode_in); > > +} > > + > > /* > > - * Link a range of blocks from one file to another. > > + * Prepare two files for range cloning. Upon a successful return both > > inodes > > + * will have the iolock and mmaplock held, the page cache of the out file > > + * will be truncated, and any leases on the out file will have been broken. > > */ > > -int > > -xfs_reflink_remap_range( > > +STATIC int > > +xfs_reflink_remap_prep( > > struct file *file_in, > > loff_t pos_in, > > struct file *file_out, > > @@ -1211,19 +1233,9 @@ xfs_reflink_remap_range( > > struct xfs_inode *src = XFS_I(inode_in); > > struct inode *inode_out = file_inode(file_out); > > struct xfs_inode *dest = XFS_I(inode_out); > > - struct xfs_mount *mp = src->i_mount; > > bool same_inode = (inode_in == inode_out); > > - xfs_fileoff_t sfsbno, dfsbno; > > - xfs_filblks_t fsblen; > > - xfs_extlen_t cowextsize; > > ssize_t ret; > > > > - if (!xfs_sb_version_hasreflink(&mp->m_sb)) > > - return -EOPNOTSUPP; > > - > > - if (XFS_FORCED_SHUTDOWN(mp)) > > - return -EIO; > > - > > /* Lock both files against IO */ > > ret = xfs_iolock_two_inodes_and_break_layout(inode_in, inode_out); > > if (ret) > > @@ -1254,8 +1266,6 @@ xfs_reflink_remap_range( > > if (ret) > > goto out_unlock; > > > > - trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); > > - > > /* > > * Clear out post-eof preallocations because we don't have page cache > > * backing the delayed allocations and they'll never get freed on > > @@ -1272,6 +1282,51 @@ xfs_reflink_remap_range( > > if (ret) > > goto out_unlock; > > > > + /* Zap any page cache for the destination file's range. */ > > + truncate_inode_pages_range(&inode_out->i_data, pos_out, > > + PAGE_ALIGN(pos_out + len) - 1); > > + return 0; > > +out_unlock: > > + xfs_reflink_remap_unlock(file_in, file_out); > > + return ret; > > +} > > + > > +/* > > + * Link a range of blocks from one file to another. > > + */ > > +int > > +xfs_reflink_remap_range( > > + struct file *file_in, > > + loff_t pos_in, > > + struct file *file_out, > > + loff_t pos_out, > > + u64 len, > > + bool is_dedupe) > > +{ > > + struct inode *inode_in = file_inode(file_in); > > + struct xfs_inode *src = XFS_I(inode_in); > > + struct inode *inode_out = file_inode(file_out); > > + struct xfs_inode *dest = XFS_I(inode_out); > > + struct xfs_mount *mp = src->i_mount; > > + xfs_fileoff_t sfsbno, dfsbno; > > + xfs_filblks_t fsblen; > > + xfs_extlen_t cowextsize; > > + ssize_t ret; > > + > > + if (!xfs_sb_version_hasreflink(&mp->m_sb)) > > + return -EOPNOTSUPP; > > + > > + if (XFS_FORCED_SHUTDOWN(mp)) > > + return -EIO; > > + > > + /* Prepare and then clone file data. */ > > + ret = xfs_reflink_remap_prep(file_in, pos_in, file_out, pos_out, > > + len, is_dedupe); > > + if (ret) > > + return ret; > > + > > + trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); > > + > > dfsbno = XFS_B_TO_FSBT(mp, pos_out); > > sfsbno = XFS_B_TO_FSBT(mp, pos_in); > > fsblen = XFS_B_TO_FSB(mp, len); > > @@ -1280,10 +1335,6 @@ xfs_reflink_remap_range( > > if (ret) > > goto out_unlock; > > > > - /* Zap any page cache for the destination file's range. */ > > - truncate_inode_pages_range(&inode_out->i_data, pos_out, > > - PAGE_ALIGN(pos_out + len) - 1); > > - > > /* > > * Carry the cowextsize hint from src to dest if we're sharing the > > * entire source file to the entire destination file, the source file > > @@ -1300,12 +1351,7 @@ xfs_reflink_remap_range( > > is_dedupe); > > > > out_unlock: > > - xfs_iunlock(dest, XFS_MMAPLOCK_EXCL); > > - if (!same_inode) > > - xfs_iunlock(src, XFS_MMAPLOCK_SHARED); > > - inode_unlock(inode_out); > > - if (!same_inode) > > - inode_unlock_shared(inode_in); > > + xfs_reflink_remap_unlock(file_in, file_out); > > if (ret) > > trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); > > return ret; > > > > > > -- > Dave Chinner > [email protected]
