f2fs: Add option to limit required GC for checkpoint=disable
This extends the checkpoint option to allow checkpoint=disable:%u[%]
This allows you to specify what how much of the disk you are willing
to lose access to while mounting with checkpoint=disable. If the amount
lost would be higher, the mount will return -EAGAIN. This can be given
as a percent of total space, or in blocks.
Currently, we need to run garbage collection until the amount of holes
is smaller than the OVP space. With the new option, f2fs can mark
space as unusable up front instead of requiring garbage collection until
the number of holes is small enough.
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 676e3cf..64e5d16 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -68,6 +68,20 @@
(unsigned long long)(dirty_segments(sbi)));
}
+static ssize_t unusable_show(struct f2fs_attr *a,
+ struct f2fs_sb_info *sbi, char *buf)
+{
+ block_t unusable;
+
+ if (test_opt(sbi, DISABLE_CHECKPOINT))
+ unusable = sbi->unusable_block_count;
+ else
+ unusable = f2fs_get_unusable_blocks(sbi);
+ return snprintf(buf, PAGE_SIZE, "%llu\n",
+ (unsigned long long)unusable);
+}
+
+
static ssize_t lifetime_write_kbytes_show(struct f2fs_attr *a,
struct f2fs_sb_info *sbi, char *buf)
{
@@ -440,6 +454,7 @@
F2FS_GENERAL_RO_ATTR(lifetime_write_kbytes);
F2FS_GENERAL_RO_ATTR(features);
F2FS_GENERAL_RO_ATTR(current_reserved_blocks);
+F2FS_GENERAL_RO_ATTR(unusable);
#ifdef CONFIG_FS_ENCRYPTION
F2FS_FEATURE_RO_ATTR(encryption, FEAT_CRYPTO);
@@ -495,6 +510,7 @@
ATTR_LIST(inject_type),
#endif
ATTR_LIST(dirty_segments),
+ ATTR_LIST(unusable),
ATTR_LIST(lifetime_write_kbytes),
ATTR_LIST(features),
ATTR_LIST(reserved_blocks),