ext4: deprecate max_writeback_mb_bump sysfs attribute
This attribute is now unused so deprecate it. We still show the old
default value to keep some compatibility but we don't allow writing to
that attribute anymore.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a9c1438..eac4d30 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2380,7 +2380,10 @@
ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
const char *, size_t);
- int offset;
+ union {
+ int offset;
+ int deprecated_val;
+ } u;
};
static int parse_strtoull(const char *buf,
@@ -2449,7 +2452,7 @@
static ssize_t sbi_ui_show(struct ext4_attr *a,
struct ext4_sb_info *sbi, char *buf)
{
- unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
+ unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
}
@@ -2458,7 +2461,7 @@
struct ext4_sb_info *sbi,
const char *buf, size_t count)
{
- unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
+ unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
unsigned long t;
int ret;
@@ -2507,12 +2510,20 @@
return count;
}
+static ssize_t sbi_deprecated_show(struct ext4_attr *a,
+ struct ext4_sb_info *sbi, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
+}
+
#define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
static struct ext4_attr ext4_attr_##_name = { \
.attr = {.name = __stringify(_name), .mode = _mode }, \
.show = _show, \
.store = _store, \
- .offset = offsetof(struct ext4_sb_info, _elname), \
+ .u = { \
+ .offset = offsetof(struct ext4_sb_info, _elname),\
+ }, \
}
#define EXT4_ATTR(name, mode, show, store) \
static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
@@ -2523,6 +2534,14 @@
#define EXT4_RW_ATTR_SBI_UI(name, elname) \
EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
#define ATTR_LIST(name) &ext4_attr_##name.attr
+#define EXT4_DEPRECATED_ATTR(_name, _val) \
+static struct ext4_attr ext4_attr_##_name = { \
+ .attr = {.name = __stringify(_name), .mode = 0444 }, \
+ .show = sbi_deprecated_show, \
+ .u = { \
+ .deprecated_val = _val, \
+ }, \
+}
EXT4_RO_ATTR(delayed_allocation_blocks);
EXT4_RO_ATTR(session_write_kbytes);
@@ -2537,7 +2556,7 @@
EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
-EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
+EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
@@ -3790,7 +3809,6 @@
}
sbi->s_stripe = ext4_get_stripe_size(sbi);
- sbi->s_max_writeback_mb_bump = 128;
sbi->s_extent_max_zeroout_kb = 32;
/*