Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / jfs / jfs_discard.c

diff --git a/kernel/fs/jfs/jfs_discard.c b/kernel/fs/jfs/jfs_discard.c
new file mode 100644 (file)
index 0000000..dfcd503
--- /dev/null
+++ b/kernel/fs/jfs/jfs_discard.c
@@ -0,0 +1,121 @@
+/*
+ *   Copyright (C) Tino Reichardt, 2012
+ *
+ *   This program is free software;  you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ *   the GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program;  if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+
+#include "jfs_incore.h"
+#include "jfs_superblock.h"
+#include "jfs_discard.h"
+#include "jfs_dmap.h"
+#include "jfs_debug.h"
+
+
+/*
+ * NAME:       jfs_issue_discard()
+ *
+ * FUNCTION:   TRIM the specified block range on device, if supported
+ *
+ * PARAMETERS:
+ *     ip      - pointer to in-core inode
+ *     blkno   - starting block number to be trimmed (0..N)
+ *     nblocks - number of blocks to be trimmed
+ *
+ * RETURN VALUES:
+ *     none
+ *
+ * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
+ */
+void jfs_issue_discard(struct inode *ip, u64 blkno, u64 nblocks)
+{
+       struct super_block *sb = ip->i_sb;
+       int r = 0;
+
+       r = sb_issue_discard(sb, blkno, nblocks, GFP_NOFS, 0);
+       if (unlikely(r != 0)) {
+               jfs_err("JFS: sb_issue_discard" \
+                       "(%p, %llu, %llu, GFP_NOFS, 0) = %d => failed!\n",
+                       sb, (unsigned long long)blkno,
+                       (unsigned long long)nblocks, r);
+       }
+
+       jfs_info("JFS: sb_issue_discard" \
+               "(%p, %llu, %llu, GFP_NOFS, 0) = %d\n",
+               sb, (unsigned long long)blkno,
+               (unsigned long long)nblocks, r);
+
+       return;
+}
+
+/*
+ * NAME:       jfs_ioc_trim()
+ *
+ * FUNCTION:   attempt to discard (TRIM) all free blocks from the
+ *              filesystem.
+ *
+ * PARAMETERS:
+ *     ip      - pointer to in-core inode;
+ *     range   - the range, given by user space
+ *
+ * RETURN VALUES:
+ *     0       - success
+ *     -EIO    - i/o error
+ */
+int jfs_ioc_trim(struct inode *ip, struct fstrim_range *range)
+{
+       struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
+       struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
+       struct super_block *sb = ipbmap->i_sb;
+       int agno, agno_end;
+       u64 start, end, minlen;
+       u64 trimmed = 0;
+
+       /**
+        * convert byte values to block size of filesystem:
+        * start:       First Byte to trim
+        * len:         number of Bytes to trim from start
+        * minlen:      minimum extent length in Bytes
+        */
+       start = range->start >> sb->s_blocksize_bits;
+       end = start + (range->len >> sb->s_blocksize_bits) - 1;
+       minlen = range->minlen >> sb->s_blocksize_bits;
+       if (minlen == 0)
+               minlen = 1;
+
+       if (minlen > bmp->db_agsize ||
+           start >= bmp->db_mapsize ||
+           range->len < sb->s_blocksize)
+               return -EINVAL;
+
+       if (end >= bmp->db_mapsize)
+               end = bmp->db_mapsize - 1;
+
+       /**
+        * we trim all ag's within the range
+        */
+       agno = BLKTOAG(start, JFS_SBI(ip->i_sb));
+       agno_end = BLKTOAG(end, JFS_SBI(ip->i_sb));
+       while (agno <= agno_end) {
+               trimmed += dbDiscardAG(ip, agno, minlen);
+               agno++;
+       }
+       range->len = trimmed << sb->s_blocksize_bits;
+
+       return 0;
+}