From: Qu Wenruo <quwen...@cn.fujitsu.com>
Introduce new reconfigure ioctl and new FORCE flag for in-band dedupe
ioctls.
Now dedupe enable and reconfigure ioctl are stateful.
--------------------------------------------
| Current state | Ioctl | Next state |
--------------------------------------------
| Disabled | enable | Enabled |
| Enabled | enable | Not allowed |
| Enabled | reconf | Enabled |
| Enabled | disable | Disabled |
| Disabled | dsiable | Disabled |
| Disabled | reconf | Not allowed |
--------------------------------------------
(While disable is always stateless)
While for guys prefer stateless ioctl (myself for example), new FORCE
flag is introduced.
In FORCE mode, enable/disable is completely stateless.
--------------------------------------------
| Current state | Ioctl | Next state |
--------------------------------------------
| Disabled | enable | Enabled |
| Enabled | enable | Enabled |
| Enabled | disable | Disabled |
| Disabled | disable | Disabled |
--------------------------------------------
Also, re-configure ioctl will only modify specified fields.
Unlike enable, un-specified fields will be filled with default value.
For example:
# btrfs dedupe enable --block-size 64k /mnt
# btrfs dedupe reconfigure --limit-hash 1m /mnt
Will leads to:
dedupe blocksize: 64K
dedupe hash limit nr: 1m
While for enable:
# btrfs dedupe enable --force --block-size 64k /mnt
# btrfs dedupe enable --force --limit-hash 1m /mnt
Will reset blocksize to default value:
dedupe blocksize: 128K << reset
dedupe hash limit nr: 1m
Suggested-by: David Sterba <dste...@suse.cz>
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
Signed-off-by: Lu Fengqi <lufq.f...@cn.fujitsu.com>
---
fs/btrfs/dedupe.c | 132 ++++++++++++++++++++++++++++++-------
fs/btrfs/dedupe.h | 13 ++++
fs/btrfs/ioctl.c | 13 ++++
include/uapi/linux/btrfs.h | 11 +++-
4 files changed, 143 insertions(+), 26 deletions(-)
diff --git a/fs/btrfs/dedupe.c b/fs/btrfs/dedupe.c
index a147e148bbb8..2be3e53acc6a 100644
--- a/fs/btrfs/dedupe.c
+++ b/fs/btrfs/dedupe.c
@@ -29,6 +29,40 @@ static inline struct inmem_hash *inmem_alloc_hash(u16 algo)
GFP_NOFS);
}
+/*
+ * Copy from current dedupe info to fill dargs.
+ * For reconf case, only fill members which is uninitialized.
+ */
+static void get_dedupe_status(struct btrfs_dedupe_info *dedupe_info,
+ struct btrfs_ioctl_dedupe_args *dargs)
+{
+ int reconf = (dargs->cmd == BTRFS_DEDUPE_CTL_RECONF);
+
+ dargs->status = 1;
+
+ if (!reconf || (reconf && dargs->blocksize == (u64)-1))
+ dargs->blocksize = dedupe_info->blocksize;
+ if (!reconf || (reconf && dargs->backend == (u16)-1))
+ dargs->backend = dedupe_info->backend;
+ if (!reconf || (reconf && dargs->hash_algo == (u16)-1))
+ dargs->hash_algo = dedupe_info->hash_algo;
+
+ /*
+ * For re-configure case, if not modifying limit,
+ * therir limit will be set to 0, unlike other fields
+ */
+ if (!reconf || !(dargs->limit_nr || dargs->limit_mem)) {
+ dargs->limit_nr = dedupe_info->limit_nr;
+ dargs->limit_mem = dedupe_info->limit_nr *
+ (sizeof(struct inmem_hash) +
+ btrfs_hash_sizes[dedupe_info->hash_algo]);
+ }
+
+ /* current_nr doesn't makes sense for reconfig case */
+ if (!reconf)
+ dargs->current_nr = dedupe_info->current_nr;
+}
+
void btrfs_dedupe_status(struct btrfs_fs_info *fs_info,
struct btrfs_ioctl_dedupe_args *dargs)
{
@@ -45,15 +79,7 @@ void btrfs_dedupe_status(struct btrfs_fs_info *fs_info,
return;
}
mutex_lock(&dedupe_info->lock);
- dargs->status = 1;
- dargs->blocksize = dedupe_info->blocksize;
- dargs->backend = dedupe_info->backend;
- dargs->hash_algo = dedupe_info->hash_algo;
- dargs->limit_nr = dedupe_info->limit_nr;
- dargs->limit_mem = dedupe_info->limit_nr *
- (sizeof(struct inmem_hash) +
- btrfs_hash_sizes[dedupe_info->hash_algo]);
- dargs->current_nr = dedupe_info->current_nr;
+ get_dedupe_status(dedupe_info, dargs);
mutex_unlock(&dedupe_info->lock);
memset(dargs->__unused, -1, sizeof(dargs->__unused));
}
@@ -98,17 +124,50 @@ init_dedupe_info(struct btrfs_ioctl_dedupe_args *dargs)
static int check_dedupe_parameter(struct btrfs_fs_info *fs_info,
struct btrfs_ioctl_dedupe_args *dargs)
{
- u64 blocksize = dargs->blocksize;
- u64 limit_nr = dargs->limit_nr;
- u64 limit_mem = dargs->limit_mem;
- u16 hash_algo = dargs->hash_algo;
- u8 backend = dargs->backend;
+ struct btrfs_dedupe_info *dedupe_info = fs_info->dedupe_info;
+
+ u64 blocksize;
+ u64 limit_nr;
+ u64 limit_mem;
+ u16 hash_algo;
+ u8 backend;
/*
* Set all reserved fields to -1, allow user to detect
* unsupported optional parameters.
*/
memset(dargs->__unused, -1, sizeof(dargs->__unused));
+
+ /*
+ * For dedupe enabled fs, enable without FORCE flag is not allowed
+ */
+ if (dargs->cmd == BTRFS_DEDUPE_CTL_ENABLE && dedupe_info &&
+ !(dargs->flags & BTRFS_DEDUPE_FLAG_FORCE)) {
+ dargs->status = 1;
+ dargs->flags = (u8)-1;
+ return -EINVAL;
+ }
+
+ /* Check and copy parameters from existing dedupe info */
+ if (dargs->cmd == BTRFS_DEDUPE_CTL_RECONF) {
+ if (!dedupe_info) {
+ /* Info caller that dedupe is not enabled */
+ dargs->status = 0;
+ return -EINVAL;
+ }
+ get_dedupe_status(dedupe_info, dargs);
+ /*
+ * All unmodified parameter are already copied out
+ * go through normal validation check.
+ */
+ }
+
+ blocksize = dargs->blocksize;
+ limit_nr = dargs->limit_nr;
+ limit_mem = dargs->limit_mem;
+ hash_algo = dargs->hash_algo;
+ backend = dargs->backend;
+
if (blocksize > BTRFS_DEDUPE_BLOCKSIZE_MAX ||
blocksize < BTRFS_DEDUPE_BLOCKSIZE_MIN ||
blocksize < fs_info->sectorsize ||
@@ -129,7 +188,8 @@ static int check_dedupe_parameter(struct btrfs_fs_info
*fs_info,
/* Backend specific check */
if (backend == BTRFS_DEDUPE_BACKEND_INMEMORY) {
/* only one limit is accepted for enable*/
- if (dargs->limit_nr && dargs->limit_mem) {
+ if (dargs->cmd == BTRFS_DEDUPE_CTL_ENABLE &&
+ dargs->limit_nr && dargs->limit_mem) {
dargs->limit_nr = 0;
dargs->limit_mem = 0;
return -EINVAL;
@@ -163,18 +223,18 @@ static int check_dedupe_parameter(struct btrfs_fs_info
*fs_info,
return 0;
}
-int btrfs_dedupe_enable(struct btrfs_fs_info *fs_info,
- struct btrfs_ioctl_dedupe_args *dargs)
+/*
+ * Enable or re-configure dedupe.
+ *
+ * Caller must call check_dedupe_parameters first
+ */
+static int enable_reconfig_dedupe(struct btrfs_fs_info *fs_info,
+ struct btrfs_ioctl_dedupe_args *dargs)
{
- struct btrfs_dedupe_info *dedupe_info;
- int ret = 0;
-
- ret = check_dedupe_parameter(fs_info, dargs);
- if (ret < 0)
- return ret;
+ struct btrfs_dedupe_info *dedupe_info = fs_info->dedupe_info;
- dedupe_info = fs_info->dedupe_info;
if (dedupe_info) {
+
/* Check if we are re-enable for different dedupe config */
if (dedupe_info->blocksize != dargs->blocksize ||
dedupe_info->hash_algo != dargs->hash_algo ||
@@ -198,7 +258,29 @@ int btrfs_dedupe_enable(struct btrfs_fs_info *fs_info,
/* We must ensure dedupe_bs is modified after dedupe_info */
smp_wmb();
fs_info->dedupe_enabled = 1;
- return ret;
+ return 0;
+}
+
+int btrfs_dedupe_enable(struct btrfs_fs_info *fs_info,
+ struct btrfs_ioctl_dedupe_args *dargs)
+{
+ int ret = 0;
+
+ ret = check_dedupe_parameter(fs_info, dargs);
+ if (ret < 0)
+ return ret;
+ return enable_reconfig_dedupe(fs_info, dargs);
+}
+
+int btrfs_dedupe_reconfigure(struct btrfs_fs_info *fs_info,
+ struct btrfs_ioctl_dedupe_args *dargs)
+{
+ /*
+ * btrfs_dedupe_enable will handle everything well,
+ * since dargs contains all info we need to distinguish enable
+ * and reconfigure
+ */
+ return btrfs_dedupe_enable(fs_info, dargs);
}
static int inmem_insert_hash(struct rb_root *root,
diff --git a/fs/btrfs/dedupe.h b/fs/btrfs/dedupe.h
index fdd00355d6b5..94e97fd19011 100644
--- a/fs/btrfs/dedupe.h
+++ b/fs/btrfs/dedupe.h
@@ -90,6 +90,19 @@ static inline struct btrfs_dedupe_hash
*btrfs_dedupe_alloc_hash(u16 algo)
int btrfs_dedupe_enable(struct btrfs_fs_info *fs_info,
struct btrfs_ioctl_dedupe_args *dargs);
+/*
+ * Reconfigure given parameter for dedupe
+ * Can only be called when dedupe is already enabled
+ *
+ * dargs member which don't need to be modified should be left
+ * with 0 for limit_nr/limit_offset or -1 for other fields
+ *
+ * Return 0 for success
+ * Return <0 for any error
+ * (Same error return value with dedupe_enable)
+ */
+int btrfs_dedupe_reconfigure(struct btrfs_fs_info *fs_info,
+ struct btrfs_ioctl_dedupe_args *dargs);
/*
* Get inband dedupe info
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 510941419ff6..f4eec56e9d65 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3658,6 +3658,19 @@ static long btrfs_ioctl_dedupe_ctl(struct btrfs_root
*root, void __user *args)
btrfs_dedupe_status(fs_info, dargs);
mutex_unlock(&fs_info->dedupe_ioctl_lock);
break;
+ case BTRFS_DEDUPE_CTL_RECONF:
+ mutex_lock(&fs_info->dedupe_ioctl_lock);
+ ret = btrfs_dedupe_reconfigure(fs_info, dargs);
+ /*
+ * Also copy the result to caller for further use
+ * if enable succeeded.
+ * For error case, dargs is already set up with
+ * special values indicating error reason.
+ */
+ if (!ret)
+ btrfs_dedupe_status(fs_info, dargs);
+ mutex_unlock(&fs_info->dedupe_ioctl_lock);
+ break;
default:
/*
* Use this return value to inform progs that kernel
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 5ee51fac3652..5ee90e23e137 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -693,7 +693,16 @@ struct btrfs_ioctl_get_dev_stats {
#define BTRFS_DEDUPE_CTL_ENABLE 1
#define BTRFS_DEDUPE_CTL_DISABLE 2
#define BTRFS_DEDUPE_CTL_STATUS 3
-#define BTRFS_DEDUPE_CTL_LAST 4
+#define BTRFS_DEDUPE_CTL_RECONF 4
+#define BTRFS_DEDUPE_CTL_LAST 5
+
+/*
+ * Allow enable command to be executed on dedupe enabled fs.
+ * Make dedupe_enable ioctl to be stateless.
+ *
+ * Or only dedup_reconf ioctl can be executed on dedupe enabled fs
+ */
+#define BTRFS_DEDUPE_FLAG_FORCE (1 << 0)
/*
* This structure is used for dedupe enable/disable/configure
* and status ioctl.
--
2.18.0
