@@ -284,8 +284,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
binode->flags &= ~BTRFS_INODE_COMPRESS;
binode->flags |= BTRFS_INODE_NOCOMPRESS;
- ret = btrfs_set_prop_trans(inode, "btrfs.compression", NULL,
- 0, 0);
+ ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
if (ret && ret != -ENODATA)
goto out_drop;
} else if (fsflags & FS_COMPR_FL) {
@@ -303,14 +302,13 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
if (!comp || comp[0] == 0)
comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
- ret = btrfs_set_prop_trans(inode, "btrfs.compression", comp,
- strlen(comp), 0);
+ ret = btrfs_set_prop(inode, "btrfs.compression", comp,
+ strlen(comp), 0);
if (ret)
goto out_drop;
} else {
- ret = btrfs_set_prop_trans(inode, "btrfs.compression", NULL,
- 0, 0);
+ ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
if (ret && ret != -ENODATA)
goto out_drop;
binode->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
@@ -56,11 +56,12 @@ static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
return NULL;
}
-static int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
- const char *name, const char *value, size_t value_len,
- int flags)
+int btrfs_set_prop(struct inode *inode, const char *name, const char *value,
+ size_t value_len, int flags)
{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
const struct prop_handler *handler;
+ struct btrfs_trans_handle *trans;
int ret;
if (btrfs_root_readonly(BTRFS_I(inode)->root))
@@ -74,50 +75,40 @@ static int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
return -EINVAL;
if (value_len == 0) {
+ /* Its called to reset the property */
+ trans = btrfs_start_transaction(root, 2);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
ret = btrfs_setxattr(trans, inode, handler->xattr_name,
NULL, 0, flags);
- if (ret)
- return ret;
-
- ret = handler->apply(inode, NULL, 0);
- ASSERT(ret == 0);
-
- return ret;
+ if (!ret) {
+ ret = handler->apply(inode, NULL, 0);
+ ASSERT(ret == 0);
+ }
+ goto out;
}
ret = handler->validate(value, value_len);
if (ret)
return ret;
+
+ trans = btrfs_start_transaction(root, 2);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
ret = btrfs_setxattr(trans, inode, handler->xattr_name,
value, value_len, flags);
if (ret)
- return ret;
+ goto out;
+
ret = handler->apply(inode, value, value_len);
if (ret) {
+ /* Apply failed. Reset the property. */
btrfs_setxattr(trans, inode, handler->xattr_name,
NULL, 0, flags);
- return ret;
- }
-
- set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
-
- return 0;
-}
-
-int btrfs_set_prop_trans(struct inode *inode, const char *name,
- const char *value, size_t value_len, int flags)
-{
- struct btrfs_root *root = BTRFS_I(inode)->root;
- struct btrfs_trans_handle *trans;
- int ret;
-
- trans = btrfs_start_transaction(root, 2);
- if (IS_ERR(trans))
- return PTR_ERR(trans);
-
- ret = btrfs_set_prop(trans, inode, name, value, value_len, flags);
-
- if (!ret) {
+ } else {
+ set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
inode_inc_iversion(inode);
inode->i_ctime = current_time(inode);
set_bit(BTRFS_INODE_COPY_EVERYTHING,
@@ -125,6 +116,8 @@ int btrfs_set_prop_trans(struct inode *inode, const char *name,
ret = btrfs_update_inode(trans, root, inode);
BUG_ON(ret);
}
+
+out:
btrfs_end_transaction(trans);
return ret;
}
@@ -10,8 +10,8 @@
void __init btrfs_props_init(void);
-int btrfs_set_prop_trans(struct inode *inode, const char *name,
- const char *value, size_t value_len, int flags);
+int btrfs_set_prop(struct inode *inode, const char *name,
+ const char *value, size_t value_len, int flags);
int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path);
@@ -371,7 +371,7 @@ static int btrfs_xattr_handler_set_prop(const struct xattr_handler *handler,
size_t size, int flags)
{
name = xattr_full_name(handler, name);
- return btrfs_set_prop_trans(inode, name, value, size, flags);
+ return btrfs_set_prop(inode, name, value, size, flags);
}
static const struct xattr_handler btrfs_security_xattr_handler = {
When the property fails to pass the prop_handlers::validate() check, the thread should exit with no changes in the kernel, but as we are starting the transaction too early, we have just updated the generation even if there is no change. For example: btrfs prop get /btrfs compression compression=lzo sync btrfs in dump-super /dev/sdb | grep "^generation" generation 32 Try to set an incomplete compression type btrfs prop set /btrfs compression zli ERROR: failed to set compression for /btrfs: Invalid argument sync Set failed but generation is incremented btrfs in dump-super /dev/sdb | grep "^generation" generation 33 <-- Fix it by collapsing btrfs_set_prop_trans() into btrfs_set_prop(), which provides flexibility to start the transaction after the prop_handlers::validate() has been checked. As of now if the prop_handlers::apply() fails then we still increment the generation, but if there is strong prop_handlers::validate() then the prop_handlers::apply() can never fail. Signed-off-by: Anand Jain <anand.jain@oracle.com> --- fs/btrfs/ioctl.c | 10 ++++------ fs/btrfs/props.c | 59 +++++++++++++++++++++++++------------------------------- fs/btrfs/props.h | 4 ++-- fs/btrfs/xattr.c | 2 +- 4 files changed, 33 insertions(+), 42 deletions(-)