Commit c975cad9 authored by Stefan Roesch's avatar Stefan Roesch Committed by Jens Axboe
Browse files

fs: split off do_getxattr from getxattr 



This splits off do_getxattr function from the getxattr function. This will
allow io_uring to call it from its io worker.

Signed-off-by: default avatarStefan Roesch <shr@fb.com>
Acked-by: default avatarChristian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20220323154420.3301504-3-shr@fb.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 1a91794c

fs/internal.h

+5 −0
Original line number Diff line number Diff line
@@ -212,6 +212,11 @@ struct xattr_ctx { 
	unsigned int flags;

};





ssize_t do_getxattr(struct user_namespace *mnt_userns,

		    struct dentry *d,

		    struct xattr_ctx *ctx);



int setxattr_copy(const char __user *name, struct xattr_ctx *ctx);

int do_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,

		struct xattr_ctx *ctx);

fs/xattr.c

+38 −21
Original line number Diff line number Diff line
@@ -676,44 +676,61 @@ SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, 
/*

 * Extended attribute GET operations

 */

static ssize_t

getxattr(struct user_namespace *mnt_userns, struct dentry *d,

	 const char __user *name, void __user *value, size_t size)

ssize_t

do_getxattr(struct user_namespace *mnt_userns, struct dentry *d,

	struct xattr_ctx *ctx)

{

	ssize_t error;

	void *kvalue = NULL;

	char kname[XATTR_NAME_MAX + 1];



	error = strncpy_from_user(kname, name, sizeof(kname));

	if (error == 0 || error == sizeof(kname))

		error = -ERANGE;

	if (error < 0)

		return error;

	char *kname = ctx->kname->name;



	if (size) {

		if (size > XATTR_SIZE_MAX)

			size = XATTR_SIZE_MAX;

		kvalue = kvzalloc(size, GFP_KERNEL);

		if (!kvalue)

	if (ctx->size) {

		if (ctx->size > XATTR_SIZE_MAX)

			ctx->size = XATTR_SIZE_MAX;

		ctx->kvalue = kvzalloc(ctx->size, GFP_KERNEL);

		if (!ctx->kvalue)

			return -ENOMEM;

	}



	error = vfs_getxattr(mnt_userns, d, kname, kvalue, size);

	error = vfs_getxattr(mnt_userns, d, kname, ctx->kvalue, ctx->size);

	if (error > 0) {

		if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||

		    (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))

			posix_acl_fix_xattr_to_user(mnt_userns, d_inode(d),

						    kvalue, error);

		if (size && copy_to_user(value, kvalue, error))

							ctx->kvalue, error);

		if (ctx->size && copy_to_user(ctx->value, ctx->kvalue, error))

			error = -EFAULT;

	} else if (error == -ERANGE && size >= XATTR_SIZE_MAX) {

	} else if (error == -ERANGE && ctx->size >= XATTR_SIZE_MAX) {

		/* The file system tried to returned a value bigger

		   than XATTR_SIZE_MAX bytes. Not possible. */

		error = -E2BIG;

	}



	kvfree(kvalue);

	return error;

}



static ssize_t

getxattr(struct user_namespace *mnt_userns, struct dentry *d,

	 const char __user *name, void __user *value, size_t size)

{

	ssize_t error;

	struct xattr_name kname;

	struct xattr_ctx ctx = {

		.value    = value,

		.kvalue   = NULL,

		.size     = size,

		.kname    = &kname,

		.flags    = 0,

	};



	error = strncpy_from_user(kname.name, name, sizeof(kname.name));

	if (error == 0 || error == sizeof(kname.name))

		error = -ERANGE;

	if (error < 0)

		return error;



	error =  do_getxattr(mnt_userns, d, &ctx);



	kvfree(ctx.kvalue);

	return error;

}