From: Amir Goldstein <amir73il@xxxxxxxxxxxx>
Snapshot inode is stored differently in memory and on disk.
During store and load of snapshot inode, some of the inode flags
and fields are converted.
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxxxxx>
Signed-off-by: Yongqiang Yang <xiaoqiangnk@xxxxxxxxx>
---
fs/ext4/inode.c | 33 +++++++++++++++++++++++++++------
1 files changed, 27 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c3af773..db1706f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5201,6 +5201,17 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
*/
for (block = 0; block < EXT4_N_BLOCKS; block++)
ei->i_data[block] = raw_inode->i_block[block];
+ /* snapshot on-disk list is stored in snapshot inode on-disk version */
+ if (ext4_snapshot_file(inode)) {
+ ei->i_next_snapshot_ino =
+ le32_to_cpu(raw_inode->i_disk_version);
+ /*
+ * snapshot volume size is stored in i_disksize.
+ * in-memory i_size of snapshot files is set to 0 (disabled).
+ * enabling a snapshot is setting i_size to i_disksize.
+ */
+ inode->i_size = 0;
+ }
INIT_LIST_HEAD(&ei->i_orphan);
/*
@@ -5465,12 +5476,22 @@ static int ext4_do_update_inode(handle_t *handle,
for (block = 0; block < EXT4_N_BLOCKS; block++)
raw_inode->i_block[block] = ei->i_data[block];
- raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
- if (ei->i_extra_isize) {
- if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
- raw_inode->i_version_hi =
- cpu_to_le32(inode->i_version >> 32);
- raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
+ if (ext4_snapshot_file(inode)) {
+ /*
+ * Snapshot on-disk list overrides snapshot on-disk version.
+ * Snapshot files are not writable and have a fixed version.
+ */
+ raw_inode->i_disk_version =
+ cpu_to_le32(ei->i_next_snapshot_ino);
+ } else {
+ raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
+ if (ei->i_extra_isize) {
+ if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
+ raw_inode->i_version_hi =
+ cpu_to_le32(inode->i_version >> 32);
+ raw_inode->i_extra_isize =
+ cpu_to_le16(ei->i_extra_isize);
+ }
}
BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
--
1.7.0.4
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