X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Fzpl_file.c;h=9c27b7f1d3b2f614a0e996f980da858780ab8548;hb=30b92c1de68ced4bee235f879791ee316314a197;hp=0ef2c1558f0b38dc9c010dddf217e75f03aeabc3;hpb=adcd70bd1af405464d6dbc6b2057594cddda7a24;p=zfs.git

diff --git a/module/zfs/zpl_file.c b/module/zfs/zpl_file.c
index 0ef2c15..9c27b7f 100644
--- a/module/zfs/zpl_file.c
+++ b/module/zfs/zpl_file.c
@@ -357,21 +357,16 @@ zpl_putpage(struct page *pp, struct writeback_control *wbc, void *data)
 
 	ASSERT(PageLocked(pp));
 	ASSERT(!PageWriteback(pp));
+	ASSERT(!(current->flags & PF_NOFS));
 
 	/*
-	 * Disable the normal reclaim path for zpl_putpage().  This
-	 * ensures that all memory allocations under this call path
-	 * will never enter direct reclaim.  If this were to happen
-	 * the VM might try to write out additional pages by calling
-	 * zpl_putpage() again resulting in a deadlock.
+	 * Annotate this call path with a flag that indicates that it is
+	 * unsafe to use KM_SLEEP during memory allocations due to the
+	 * potential for a deadlock.  KM_PUSHPAGE should be used instead.
 	 */
-	if (current->flags & PF_MEMALLOC) {
-		(void) zfs_putpage(mapping->host, pp, wbc);
-	} else {
-		current->flags |= PF_MEMALLOC;
-		(void) zfs_putpage(mapping->host, pp, wbc);
-		current->flags &= ~PF_MEMALLOC;
-	}
+	current->flags |= PF_NOFS;
+	(void) zfs_putpage(mapping->host, pp, wbc);
+	current->flags &= ~PF_NOFS;
 
 	return (0);
 }
@@ -394,6 +389,50 @@ zpl_writepage(struct page *pp, struct writeback_control *wbc)
 	return zpl_putpage(pp, wbc, pp->mapping);
 }
 
+/*
+ * The only flag combination which matches the behavior of zfs_space()
+ * is FALLOC_FL_PUNCH_HOLE.  This flag was introduced in the 2.6.38 kernel.
+ */
+long
+zpl_fallocate_common(struct inode *ip, int mode, loff_t offset, loff_t len)
+{
+	cred_t *cr = CRED();
+	int error = -EOPNOTSUPP;
+
+	if (mode & FALLOC_FL_KEEP_SIZE)
+		return (-EOPNOTSUPP);
+
+	crhold(cr);
+
+#ifdef FALLOC_FL_PUNCH_HOLE
+	if (mode & FALLOC_FL_PUNCH_HOLE) {
+		flock64_t bf;
+
+		bf.l_type = F_WRLCK;
+		bf.l_whence = 0;
+		bf.l_start = offset;
+		bf.l_len = len;
+		bf.l_pid = 0;
+
+		error = -zfs_space(ip, F_FREESP, &bf, FWRITE, offset, cr);
+	}
+#endif /* FALLOC_FL_PUNCH_HOLE */
+
+	crfree(cr);
+
+	ASSERT3S(error, <=, 0);
+	return (error);
+}
+
+#ifdef HAVE_FILE_FALLOCATE
+static long
+zpl_fallocate(struct file *filp, int mode, loff_t offset, loff_t len)
+{
+	return zpl_fallocate_common(filp->f_path.dentry->d_inode,
+	    mode, offset, len);
+}
+#endif /* HAVE_FILE_FALLOCATE */
+
 const struct address_space_operations zpl_address_space_operations = {
 	.readpages	= zpl_readpages,
 	.readpage	= zpl_readpage,
@@ -410,6 +449,9 @@ const struct file_operations zpl_file_operations = {
 	.readdir	= zpl_readdir,
 	.mmap		= zpl_mmap,
 	.fsync		= zpl_fsync,
+#ifdef HAVE_FILE_FALLOCATE
+	.fallocate      = zpl_fallocate,
+#endif /* HAVE_FILE_FALLOCATE */
 };
 
 const struct file_operations zpl_dir_file_operations = {