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authorDaniel Xu <dxu@dxuuu.xyz>2020-03-12 13:03:15 -0700
committerTejun Heo <tj@kernel.org>2020-03-16 15:53:47 -0400
commita46a22955bae16fc5a756af7188d3ccb25c3f797 (patch)
treec1a356cde80b186783225a8cb2d8f56f9474c1b3
parentfdc85222d58eb6e19ac11181024ac766b19dc470 (diff)
kernfs: Add removed_size out param for simple_xattr_set
This helps set up size accounting in the next commit. Without this out param, it's difficult to find out the removed xattr size without taking a lock for longer and walking the xattr linked list twice. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Acked-by: Chris Down <chris@chrisdown.name> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
-rw-r--r--fs/kernfs/inode.c2
-rw-r--r--fs/xattr.c11
-rw-r--r--include/linux/xattr.h3
-rw-r--r--mm/shmem.c2
4 files changed, 14 insertions, 4 deletions
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index d0f7a5abd9a9..5f10ae95fbfa 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -303,7 +303,7 @@ int kernfs_xattr_set(struct kernfs_node *kn, const char *name,
if (!attrs)
return -ENOMEM;
- return simple_xattr_set(&attrs->xattrs, name, value, size, flags);
+ return simple_xattr_set(&attrs->xattrs, name, value, size, flags, NULL);
}
static int kernfs_vfs_xattr_get(const struct xattr_handler *handler,
diff --git a/fs/xattr.c b/fs/xattr.c
index 0d3c9b4d1914..e13265e65871 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -860,6 +860,7 @@ int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
* @value: value of the xattr. If %NULL, will remove the attribute.
* @size: size of the new xattr
* @flags: %XATTR_{CREATE|REPLACE}
+ * @removed_size: returns size of the removed xattr, -1 if none removed
*
* %XATTR_CREATE is set, the xattr shouldn't exist already; otherwise fails
* with -EEXIST. If %XATTR_REPLACE is set, the xattr should exist;
@@ -868,7 +869,8 @@ int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
* Returns 0 on success, -errno on failure.
*/
int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
- const void *value, size_t size, int flags)
+ const void *value, size_t size, int flags,
+ ssize_t *removed_size)
{
struct simple_xattr *xattr;
struct simple_xattr *new_xattr = NULL;
@@ -895,8 +897,12 @@ int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
err = -EEXIST;
} else if (new_xattr) {
list_replace(&xattr->list, &new_xattr->list);
+ if (removed_size)
+ *removed_size = xattr->size;
} else {
list_del(&xattr->list);
+ if (removed_size)
+ *removed_size = xattr->size;
}
goto out;
}
@@ -908,6 +914,9 @@ int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
list_add(&new_xattr->list, &xattrs->head);
xattr = NULL;
}
+
+ if (removed_size)
+ *removed_size = -1;
out:
spin_unlock(&xattrs->lock);
if (xattr) {
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 6dad031be3c2..4cf6e11f4a3c 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -102,7 +102,8 @@ struct simple_xattr *simple_xattr_alloc(const void *value, size_t size);
int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
void *buffer, size_t size);
int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
- const void *value, size_t size, int flags);
+ const void *value, size_t size, int flags,
+ ssize_t *removed_size);
ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer,
size_t size);
void simple_xattr_list_add(struct simple_xattrs *xattrs,
diff --git a/mm/shmem.c b/mm/shmem.c
index c8f7540ef048..e6a7549faf20 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -3243,7 +3243,7 @@ static int shmem_xattr_handler_set(const struct xattr_handler *handler,
struct shmem_inode_info *info = SHMEM_I(inode);
name = xattr_full_name(handler, name);
- return simple_xattr_set(&info->xattrs, name, value, size, flags);
+ return simple_xattr_set(&info->xattrs, name, value, size, flags, NULL);
}
static const struct xattr_handler shmem_security_xattr_handler = {