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Diffstat (limited to 'fs/ext4/super.c')
-rw-r--r--fs/ext4/super.c33
1 files changed, 32 insertions, 1 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 16a4ce704460..7ea7178750f2 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4425,6 +4425,36 @@ static int ext4_handle_clustersize(struct super_block *sb)
return 0;
}
+/*
+ * ext4_atomic_write_init: Initializes filesystem min & max atomic write units.
+ * @sb: super block
+ * TODO: Later add support for bigalloc
+ */
+static void ext4_atomic_write_init(struct super_block *sb)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct block_device *bdev = sb->s_bdev;
+
+ if (!bdev_can_atomic_write(bdev))
+ return;
+
+ if (!ext4_has_feature_extents(sb))
+ return;
+
+ sbi->s_awu_min = max(sb->s_blocksize,
+ bdev_atomic_write_unit_min_bytes(bdev));
+ sbi->s_awu_max = min(sb->s_blocksize,
+ bdev_atomic_write_unit_max_bytes(bdev));
+ if (sbi->s_awu_min && sbi->s_awu_max &&
+ sbi->s_awu_min <= sbi->s_awu_max) {
+ ext4_msg(sb, KERN_NOTICE, "Supports (experimental) DIO atomic writes awu_min: %u, awu_max: %u",
+ sbi->s_awu_min, sbi->s_awu_max);
+ } else {
+ sbi->s_awu_min = 0;
+ sbi->s_awu_max = 0;
+ }
+}
+
static void ext4_fast_commit_init(struct super_block *sb)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -5336,6 +5366,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
spin_lock_init(&sbi->s_bdev_wb_lock);
+ ext4_atomic_write_init(sb);
ext4_fast_commit_init(sb);
sb->s_root = NULL;
@@ -7329,7 +7360,7 @@ static struct file_system_type ext4_fs_type = {
.init_fs_context = ext4_init_fs_context,
.parameters = ext4_param_specs,
.kill_sb = ext4_kill_sb,
- .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
+ .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME,
};
MODULE_ALIAS_FS("ext4");