cifs: add fiemap support

Useful for improved copy performance as well as for
applications which query allocated ranges of sparse
files.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

8 files changed, 132 insertions, 2 deletions

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 54c065ada4de..b1a5fcfa3ce1 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -986,6 +986,7 @@ const struct inode_operations cifs_file_inode_ops = {
         .getattr = cifs_getattr,
         .permission = cifs_permission,
         .listxattr = cifs_listxattr,
+        .fiemap = cifs_fiemap,
 };
 
 const struct inode_operations cifs_symlink_inode_ops = {
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index 5c0298b9998f..c47d93d74d75 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -84,6 +84,8 @@ extern int cifs_revalidate_mapping(struct inode *inode);
 extern int cifs_zap_mapping(struct inode *inode);
 extern int cifs_getattr(const struct path *, struct kstat *, u32, unsigned int);
 extern int cifs_setattr(struct dentry *, struct iattr *);
+extern int cifs_fiemap(struct inode *, struct fiemap_extent_info *, u64 start,
+                       u64 len);
 
 extern const struct inode_operations cifs_file_inode_ops;
 extern const struct inode_operations cifs_symlink_inode_ops;
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 0dc55f4e6929..5ffe0e538cec 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -493,6 +493,9 @@ struct smb_version_operations {
                          char *full_path,
                          umode_t mode,
                          dev_t device_number);
+        /* version specific fiemap implementation */
+        int (*fiemap)(struct cifs_tcon *tcon, struct cifsFileInfo *,
+                      struct fiemap_extent_info *, u64, u64);
 };
 
 struct smb_version_values {
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 538fd7d807e4..d7cc62252634 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -2116,6 +2116,43 @@ int cifs_getattr(const struct path *path, struct kstat *stat,
         return rc;
 }
 
+int cifs_fiemap(struct inode *inode, struct fiemap_extent_info *fei, u64 start,
+                u64 len)
+{
+        struct cifsInodeInfo *cifs_i = CIFS_I(inode);
+        struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_i->vfs_inode.i_sb);
+        struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
+        struct TCP_Server_Info *server = tcon->ses->server;
+        struct cifsFileInfo *cfile;
+        int rc;
+
+        /*
+         * We need to be sure that all dirty pages are written as they
+         * might fill holes on the server.
+         */
+        if (!CIFS_CACHE_READ(CIFS_I(inode)) && inode->i_mapping &&
+            inode->i_mapping->nrpages != 0) {
+                rc = filemap_fdatawait(inode->i_mapping);
+                if (rc) {
+                        mapping_set_error(inode->i_mapping, rc);
+                        return rc;
+                }
+        }
+
+        cfile = find_readable_file(cifs_i, false);
+        if (cfile == NULL)
+                return -EINVAL;
+
+        if (server->ops->fiemap) {
+                rc = server->ops->fiemap(tcon, cfile, fei, start, len);
+                cifsFileInfo_put(cfile);
+                return rc;
+        }
+
+        cifsFileInfo_put(cfile);
+        return -ENOTSUPP;
+}
+
 static int cifs_truncate_page(struct address_space *mapping, loff_t from)
 {
         pgoff_t index = from >> PAGE_SHIFT;
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 4002e1433ccb..78bca7d46eac 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -2886,6 +2886,79 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon,
         return rc;
 }
 
+static int smb3_fiemap(struct cifs_tcon *tcon,
+                       struct cifsFileInfo *cfile,
+                       struct fiemap_extent_info *fei, u64 start, u64 len)
+{
+        unsigned int xid;
+        struct file_allocated_range_buffer in_data, *out_data;
+        u32 out_data_len;
+        int i, num, rc, flags, last_blob;
+        u64 next;
+
+        if (fiemap_check_flags(fei, FIEMAP_FLAG_SYNC))
+                return -EBADR;
+
+        xid = get_xid();
+ again:
+        in_data.file_offset = cpu_to_le64(start);
+        in_data.length = cpu_to_le64(len);
+
+        rc = SMB2_ioctl(xid, tcon, cfile->fid.persistent_fid,
+                        cfile->fid.volatile_fid,
+                        FSCTL_QUERY_ALLOCATED_RANGES, true,
+                        (char *)&in_data, sizeof(in_data),
+                        1024 * sizeof(struct file_allocated_range_buffer),
+                        (char **)&out_data, &out_data_len);
+        if (rc == -E2BIG) {
+                last_blob = 0;
+                rc = 0;
+        } else
+                last_blob = 1;
+        if (rc)
+                goto out;
+
+        if (out_data_len < sizeof(struct file_allocated_range_buffer)) {
+                rc = -EINVAL;
+                goto out;
+        }
+        if (out_data_len % sizeof(struct file_allocated_range_buffer)) {
+                rc = -EINVAL;
+                goto out;
+        }
+
+        num = out_data_len / sizeof(struct file_allocated_range_buffer);
+        for (i = 0; i < num; i++) {
+                flags = 0;
+                if (i == num - 1 && last_blob)
+                        flags |= FIEMAP_EXTENT_LAST;
+
+                rc = fiemap_fill_next_extent(fei,
+                                le64_to_cpu(out_data[i].file_offset),
+                                le64_to_cpu(out_data[i].file_offset),
+                                le64_to_cpu(out_data[i].length),
+                                flags);
+                if (rc < 0)
+                        goto out;
+                if (rc == 1) {
+                        rc = 0;
+                        goto out;
+                }
+        }
+
+        if (!last_blob) {
+                next = le64_to_cpu(out_data[num - 1].file_offset) +
+                  le64_to_cpu(out_data[num - 1].length);
+                len = len - (next - start);
+                start = next;
+                goto again;
+        }
+
+ out:
+        free_xid(xid);
+        kfree(out_data);
+        return rc;
+}
 
 static long smb3_fallocate(struct file *file, struct cifs_tcon *tcon, int mode,
                            loff_t off, loff_t len)
@@ -4054,6 +4127,7 @@ struct smb_version_operations smb20_operations = {
         .next_header = smb2_next_header,
         .ioctl_query_info = smb2_ioctl_query_info,
         .make_node = smb2_make_node,
+        .fiemap = smb3_fiemap,
 };
 
 struct smb_version_operations smb21_operations = {
@@ -4153,6 +4227,7 @@ struct smb_version_operations smb21_operations = {
         .next_header = smb2_next_header,
         .ioctl_query_info = smb2_ioctl_query_info,
         .make_node = smb2_make_node,
+        .fiemap = smb3_fiemap,
 };
 
 struct smb_version_operations smb30_operations = {
@@ -4261,6 +4336,7 @@ struct smb_version_operations smb30_operations = {
         .next_header = smb2_next_header,
         .ioctl_query_info = smb2_ioctl_query_info,
         .make_node = smb2_make_node,
+        .fiemap = smb3_fiemap,
 };
 
 struct smb_version_operations smb311_operations = {
@@ -4370,6 +4446,7 @@ struct smb_version_operations smb311_operations = {
         .next_header = smb2_next_header,
         .ioctl_query_info = smb2_ioctl_query_info,
         .make_node = smb2_make_node,
+        .fiemap = smb3_fiemap,
 };
 
 struct smb_version_values smb20_values = {
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index a932dccafc5b..634800c0bc06 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2622,7 +2622,7 @@ SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
                 trace_smb3_fsctl_err(xid, persistent_fid, tcon->tid,
                                 ses->Suid, 0, opcode, rc);
 
-        if ((rc != 0) && (rc != -EINVAL)) {
+        if ((rc != 0) && (rc != -EINVAL) && (rc != -E2BIG)) {
                 cifs_stats_fail_inc(tcon, SMB2_IOCTL_HE);
                 goto ioctl_exit;
         } else if (rc == -EINVAL) {
@@ -2631,6 +2631,11 @@ SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
                         cifs_stats_fail_inc(tcon, SMB2_IOCTL_HE);
                         goto ioctl_exit;
                 }
+        } else if (rc == -E2BIG) {
+                if (opcode != FSCTL_QUERY_ALLOCATED_RANGES) {
+                        cifs_stats_fail_inc(tcon, SMB2_IOCTL_HE);
+                        goto ioctl_exit;
+                }
         }
 
         /* check if caller wants to look at return data or just return rc */
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 58158e91b9d1..82686e9d9e05 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -868,6 +868,11 @@ struct fsctl_get_integrity_information_rsp {
         __le32  ClusterSizeInBytes;
 } __packed;
 
+struct file_allocated_range_buffer {
+        __le64  file_offset;
+        __le64  length;
+} __packed;
+
 /* Integrity ChecksumAlgorithm choices for above */
 #define CHECKSUM_TYPE_NONE      0x0000
 #define CHECKSUM_TYPE_CRC64     0x0002
diff --git a/fs/cifs/smbfsctl.h b/fs/cifs/smbfsctl.h
index 9b3459b9a5ce..08628e6a42ac 100644
--- a/fs/cifs/smbfsctl.h
+++ b/fs/cifs/smbfsctl.h
@@ -103,7 +103,7 @@
 #define FSCTL_SET_ZERO_ON_DEALLOC    0x00090194 /* BB add struct */
 #define FSCTL_SET_SHORT_NAME_BEHAVIOR 0x000901B4 /* BB add struct */
 #define FSCTL_GET_INTEGRITY_INFORMATION 0x0009027C
-#define FSCTL_QUERY_ALLOCATED_RANGES 0x000940CF /* BB add struct */
+#define FSCTL_QUERY_ALLOCATED_RANGES 0x000940CF
 #define FSCTL_SET_DEFECT_MANAGEMENT  0x00098134 /* BB add struct */
 #define FSCTL_FILE_LEVEL_TRIM        0x00098208 /* BB add struct */
 #define FSCTL_DUPLICATE_EXTENTS_TO_FILE 0x00098344