From: Darrick J. Wong <djwong@xxxxxxxxxx>
Add an administrative interface so that userspace can hide an allocation
group from block allocation.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
fs/xfs/libxfs/xfs_ag.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/libxfs/xfs_fs.h | 5 ++++
fs/xfs/xfs_ioctl.c | 4 +++-
3 files changed, 62 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/libxfs/xfs_ag.c b/fs/xfs/libxfs/xfs_ag.c
index a855f943cfad9..183f46edb5d15 100644
--- a/fs/xfs/libxfs/xfs_ag.c
+++ b/fs/xfs/libxfs/xfs_ag.c
@@ -1075,6 +1075,54 @@ xfs_ag_extend_space(
return 0;
}
+/* Compute the AG geometry flags. */
+static inline uint32_t
+xfs_ag_calc_geoflags(
+ struct xfs_perag *pag)
+{
+ uint32_t ret = 0;
+
+ if (xfs_perag_prohibits_alloc(pag))
+ ret |= XFS_AG_FLAG_NOALLOC;
+
+ return ret;
+}
+
+/*
+ * Compare the current AG geometry flags against the flags in the AG geometry
+ * structure and update the AG state to reflect any changes, then update the
+ * struct to reflect the current status.
+ */
+static inline int
+xfs_ag_update_geoflags(
+ struct xfs_perag *pag,
+ struct xfs_ag_geometry *ageo,
+ uint32_t new_flags)
+{
+ uint32_t old_flags = xfs_ag_calc_geoflags(pag);
+ int error;
+
+ if (!(new_flags & XFS_AG_FLAG_UPDATE)) {
+ ageo->ag_flags = old_flags;
+ return 0;
+ }
+
+ if ((old_flags & XFS_AG_FLAG_NOALLOC) &&
+ !(new_flags & XFS_AG_FLAG_NOALLOC)) {
+ xfs_ag_clear_noalloc(pag);
+ }
+
+ if (!(old_flags & XFS_AG_FLAG_NOALLOC) &&
+ (new_flags & XFS_AG_FLAG_NOALLOC)) {
+ error = xfs_ag_set_noalloc(pag);
+ if (error)
+ return error;
+ }
+
+ ageo->ag_flags = xfs_ag_calc_geoflags(pag);
+ return 0;
+}
+
/* Retrieve AG geometry. */
int
xfs_ag_get_geometry(
@@ -1086,6 +1134,7 @@ xfs_ag_get_geometry(
struct xfs_agi *agi;
struct xfs_agf *agf;
unsigned int freeblks;
+ uint32_t inflags = ageo->ag_flags;
int error;
/* Lock the AG headers. */
@@ -1096,6 +1145,10 @@ xfs_ag_get_geometry(
if (error)
goto out_agi;
+ error = xfs_ag_update_geoflags(pag, ageo, inflags);
+ if (error)
+ goto out;
+
/* Fill out form. */
memset(ageo, 0, sizeof(*ageo));
ageo->ag_number = pag->pag_agno;
@@ -1113,6 +1166,7 @@ xfs_ag_get_geometry(
ageo->ag_freeblks = freeblks;
xfs_ag_geom_health(pag, ageo);
+out:
/* Release resources. */
xfs_buf_relse(agf_bp);
out_agi:
diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index 4159e96d01ae6..96688f9301e08 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -305,6 +305,11 @@ struct xfs_ag_geometry {
#define XFS_AG_GEOM_SICK_REFCNTBT (1 << 9) /* reference counts */
#define XFS_AG_GEOM_SICK_INODES (1 << 10) /* bad inodes were seen */
+#define XFS_AG_FLAG_UPDATE (1 << 0) /* update flags */
+#define XFS_AG_FLAG_NOALLOC (1 << 1) /* do not allocate from this AG */
+#define XFS_AG_FLAG_ALL (XFS_AG_FLAG_UPDATE | \
+ XFS_AG_FLAG_NOALLOC)
+
/*
* Structures for XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG & XFS_IOC_FSGROWFSRT
*/
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index f85d5f142d180..d17b17e7eea1d 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -976,10 +976,12 @@ xfs_ioc_ag_geometry(
if (copy_from_user(&ageo, arg, sizeof(ageo)))
return -EFAULT;
- if (ageo.ag_flags)
+ if (ageo.ag_flags & ~XFS_AG_FLAG_ALL)
return -EINVAL;
if (memchr_inv(&ageo.ag_reserved, 0, sizeof(ageo.ag_reserved)))
return -EINVAL;
+ if ((ageo.ag_flags & XFS_AG_FLAG_UPDATE) && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
pag = xfs_perag_get(mp, ageo.ag_number);
if (!pag)
