| Message ID | 20250206064511.2323878-12-hch@lst.de (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | [01/43] xfs: factor out a xfs_rt_check_size helper | expand |
On Thu, Feb 06, 2025 at 07:44:27AM +0100, Christoph Hellwig wrote: > There is no point in reserving more space than actually available > on the data device for the worst case scenario that is unlikely to > happen. Reserve at most 1/4th of the data device blocks, which is > still a heuristic. I wonder if this should be a bugfix for 6.14? Since one could format a filesystem with a 1T data volume and a 200T rt volume and immediately be out of space on the data volume. Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> --D > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > fs/xfs/libxfs/xfs_metafile.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/xfs/libxfs/xfs_metafile.c b/fs/xfs/libxfs/xfs_metafile.c > index 88f011750add..225923e463c4 100644 > --- a/fs/xfs/libxfs/xfs_metafile.c > +++ b/fs/xfs/libxfs/xfs_metafile.c > @@ -260,6 +260,7 @@ xfs_metafile_resv_init( > struct xfs_rtgroup *rtg = NULL; > xfs_filblks_t used = 0, target = 0; > xfs_filblks_t hidden_space; > + xfs_rfsblock_t dblocks_avail = mp->m_sb.sb_dblocks / 4; > int error = 0; > > if (!xfs_has_metadir(mp)) > @@ -297,6 +298,8 @@ xfs_metafile_resv_init( > */ > if (used > target) > target = used; > + else if (target > dblocks_avail) > + target = dblocks_avail; > hidden_space = target - used; > > error = xfs_dec_fdblocks(mp, hidden_space, true); > -- > 2.45.2 > >
On Thu, Feb 06, 2025 at 12:52:49PM -0800, Darrick J. Wong wrote: > On Thu, Feb 06, 2025 at 07:44:27AM +0100, Christoph Hellwig wrote: > > There is no point in reserving more space than actually available > > on the data device for the worst case scenario that is unlikely to > > happen. Reserve at most 1/4th of the data device blocks, which is > > still a heuristic. > > I wonder if this should be a bugfix for 6.14? Since one could format a > filesystem with a 1T data volume and a 200T rt volume and immediately be > out of space on the data volume. Yeah. But for this to be safe I think we also need the previous patch to sitch to the global reservations. Which at least in the current form sits on top of the freecounter refactoring..
On Fri, Feb 07, 2025 at 05:19:31AM +0100, Christoph Hellwig wrote: > On Thu, Feb 06, 2025 at 12:52:49PM -0800, Darrick J. Wong wrote: > > On Thu, Feb 06, 2025 at 07:44:27AM +0100, Christoph Hellwig wrote: > > > There is no point in reserving more space than actually available > > > on the data device for the worst case scenario that is unlikely to > > > happen. Reserve at most 1/4th of the data device blocks, which is > > > still a heuristic. > > > > I wonder if this should be a bugfix for 6.14? Since one could format a > > filesystem with a 1T data volume and a 200T rt volume and immediately be > > out of space on the data volume. > > Yeah. But for this to be safe I think we also need the previous patch > to sitch to the global reservations. Which at least in the current > form sits on top of the freecounter refactoring.. <nod> Well at the moment we're safe against that scenario because mkfs will blow up and not complete the format. :D --D
diff --git a/fs/xfs/libxfs/xfs_metafile.c b/fs/xfs/libxfs/xfs_metafile.c index 88f011750add..225923e463c4 100644 --- a/fs/xfs/libxfs/xfs_metafile.c +++ b/fs/xfs/libxfs/xfs_metafile.c @@ -260,6 +260,7 @@ xfs_metafile_resv_init( struct xfs_rtgroup *rtg = NULL; xfs_filblks_t used = 0, target = 0; xfs_filblks_t hidden_space; + xfs_rfsblock_t dblocks_avail = mp->m_sb.sb_dblocks / 4; int error = 0; if (!xfs_has_metadir(mp)) @@ -297,6 +298,8 @@ xfs_metafile_resv_init( */ if (used > target) target = used; + else if (target > dblocks_avail) + target = dblocks_avail; hidden_space = target - used; error = xfs_dec_fdblocks(mp, hidden_space, true);
There is no point in reserving more space than actually available on the data device for the worst case scenario that is unlikely to happen. Reserve at most 1/4th of the data device blocks, which is still a heuristic. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/xfs/libxfs/xfs_metafile.c | 3 +++ 1 file changed, 3 insertions(+)