[RFC PATCH 3/4] xfs: add FREE_EOFBLOCKS ioctl

[Brian Foster]

The XFS_IOC_FREE_EOFBLOCKS ioctl allows users to invoke an EOFBLOCKS
scan. The xfs_eofblocks structure is defined to support the command
parameters (quota type/id and minimum file size).

Signed-off-by: Brian Foster <bfoster at redhat.com>
---
 fs/xfs/xfs_fs.h       |   10 ++++++++++
 fs/xfs/xfs_ioctl.c    |   25 +++++++++++++++++++++++++
 fs/xfs/xfs_quota.h    |    1 +
 fs/xfs/xfs_quotaops.c |    2 +-
 4 files changed, 37 insertions(+), 1 deletions(-)

diff --git a/fs/xfs/xfs_fs.h b/fs/xfs/xfs_fs.h
index c13fed8..6f93db9 100644
--- a/fs/xfs/xfs_fs.h
+++ b/fs/xfs/xfs_fs.h
@@ -339,6 +339,15 @@ typedef struct xfs_error_injection {
 
 
 /*
+ * Speculative preallocation trimming.
+ */
+typedef struct xfs_eofblocks {
+	__u32		id;		/* quota id */
+	__u32		qtype;		/* quota type */
+	__u64		min_file_size;	/* minimum file size */
+} xfs_eofblocks_t;
+
+/*
  * The user-level Handle Request interface structure.
  */
 typedef struct xfs_fsop_handlereq {
@@ -456,6 +465,7 @@ typedef struct xfs_handle {
 /*	XFS_IOC_GETBIOSIZE ---- deprecated 47	   */
 #define XFS_IOC_GETBMAPX	_IOWR('X', 56, struct getbmap)
 #define XFS_IOC_ZERO_RANGE	_IOW ('X', 57, struct xfs_flock64)
+#define XFS_IOC_FREE_EOFBLOCKS	_IOR ('X', 58, struct xfs_eofblocks)
 
 /*
  * ioctl commands that replace IRIX syssgi()'s
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 0e0232c..b91cbcd 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1602,6 +1602,31 @@ xfs_file_ioctl(
 		error = xfs_errortag_clearall(mp, 1);
 		return -error;
 
+	case XFS_IOC_FREE_EOFBLOCKS: {
+		struct xfs_eofblocks eofb;
+		int qtype;
+
+		if (copy_from_user(&eofb, arg, sizeof(eofb)))
+			return -XFS_ERROR(EFAULT);
+
+		qtype = xfs_quota_type(eofb.qtype);
+
+		/*
+		 * TODO: The filtering code currently uses the id in the inode.
+		 * Therefore, I don't think it really matters whether the
+		 * particular quota type is enabled (and the dquot is attached).
+		 *
+		 * Alternatively, we could filter by dquot type. This would
+		 * mean we might have to make sure dquot's are attached during
+		 * the scan and that the particular quota type is enabled. I'm
+		 * not sure that this buys us anything.
+		 */
+
+		/* TODO: might want to just use the eofb structure here */
+		error = xfs_inodes_free_eofblocks(mp, qtype, eofb.id, eofb.min_file_size, EOFBLOCKS_WAIT);
+		return -error;
+	}
+
 	default:
 		return -ENOTTY;
 	}
diff --git a/fs/xfs/xfs_quota.h b/fs/xfs/xfs_quota.h
index b50ec5b..3ec6224 100644
--- a/fs/xfs/xfs_quota.h
+++ b/fs/xfs/xfs_quota.h
@@ -379,6 +379,7 @@ static inline int xfs_trans_reserve_quota_bydquots(struct xfs_trans *tp,
 extern int xfs_qm_dqcheck(struct xfs_mount *, xfs_disk_dquot_t *,
 				xfs_dqid_t, uint, uint, char *);
 extern int xfs_mount_reset_sbqflags(struct xfs_mount *);
+int xfs_quota_type(int);
 
 #endif	/* __KERNEL__ */
 #endif	/* __XFS_QUOTA_H__ */
diff --git a/fs/xfs/xfs_quotaops.c b/fs/xfs/xfs_quotaops.c
index fed504f..fe15aa7 100644
--- a/fs/xfs/xfs_quotaops.c
+++ b/fs/xfs/xfs_quotaops.c
@@ -28,7 +28,7 @@
 #include <linux/quota.h>
 
 
-STATIC int
+int
 xfs_quota_type(int type)
 {
 	switch (type) {
-- 
1.7.7.6