gfs2: Implement SEEK_HOLE / SEEK_DATA via iomap

So far, lseek on gfs2 did not report holes.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index c7a904a..8fefb80 100644 (file)
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -60,9 +60,7 @@ static loff_t gfs2_llseek(struct file *file, loff_t offset, int whence)
        loff_t error;
 
        switch (whence) {
-       case SEEK_END: /* These reference inode->i_size */
-       case SEEK_DATA:
-       case SEEK_HOLE:
+       case SEEK_END:
                error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
                                           &i_gh);
                if (!error) {
@@ -70,8 +68,21 @@ static loff_t gfs2_llseek(struct file *file, loff_t offset, int whence)
                        gfs2_glock_dq_uninit(&i_gh);
                }
                break;
+
+       case SEEK_DATA:
+               error = gfs2_seek_data(file, offset);
+               break;
+
+       case SEEK_HOLE:
+               error = gfs2_seek_hole(file, offset);
+               break;
+
        case SEEK_CUR:
        case SEEK_SET:
+               /*
+                * These don't reference inode->i_size and don't depend on the
+                * block mapping, so we don't need the glock.
+                */
                error = generic_file_llseek(file, offset, whence);
                break;
        default:

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 321da48..4749a6b 100644 (file)
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -2029,6 +2029,44 @@ out:
        return ret;
 }
 
+loff_t gfs2_seek_data(struct file *file, loff_t offset)
+{
+       struct inode *inode = file->f_mapping->host;
+       struct gfs2_inode *ip = GFS2_I(inode);
+       struct gfs2_holder gh;
+       loff_t ret;
+
+       inode_lock_shared(inode);
+       ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
+       if (!ret)
+               ret = iomap_seek_data(inode, offset, &gfs2_iomap_ops);
+       gfs2_glock_dq_uninit(&gh);
+       inode_unlock_shared(inode);
+
+       if (ret < 0)
+               return ret;
+       return vfs_setpos(file, ret, inode->i_sb->s_maxbytes);
+}
+
+loff_t gfs2_seek_hole(struct file *file, loff_t offset)
+{
+       struct inode *inode = file->f_mapping->host;
+       struct gfs2_inode *ip = GFS2_I(inode);
+       struct gfs2_holder gh;
+       loff_t ret;
+
+       inode_lock_shared(inode);
+       ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
+       if (!ret)
+               ret = iomap_seek_hole(inode, offset, &gfs2_iomap_ops);
+       gfs2_glock_dq_uninit(&gh);
+       inode_unlock_shared(inode);
+
+       if (ret < 0)
+               return ret;
+       return vfs_setpos(file, ret, inode->i_sb->s_maxbytes);
+}
+
 const struct inode_operations gfs2_file_iops = {
        .permission = gfs2_permission,
        .setattr = gfs2_setattr,

diff --git a/fs/gfs2/inode.h b/fs/gfs2/inode.h
index aace8ce..b5b6341 100644 (file)
--- a/fs/gfs2/inode.h
+++ b/fs/gfs2/inode.h
@@ -109,6 +109,8 @@ extern int gfs2_setattr_simple(struct inode *inode, struct iattr *attr);
 extern struct inode *gfs2_lookup_simple(struct inode *dip, const char *name);
 extern void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf);
 extern int gfs2_open_common(struct inode *inode, struct file *file);
+extern loff_t gfs2_seek_data(struct file *file, loff_t offset);
+extern loff_t gfs2_seek_hole(struct file *file, loff_t offset);
 
 extern const struct inode_operations gfs2_file_iops;
 extern const struct inode_operations gfs2_dir_iops;