Reviewed by: Steve French <steve.french@xxxxxxxxxxxxxxx>
(for the non-lustre pieces of the patch)
On Mon, May 23, 2016 at 8:09 AM, Andreas Gruenbacher
<agruenba@xxxxxxxxxx> wrote:
> Currently, getxattr() and setxattr() check for the xattr names
> "system.posix_acl_{access,default}" and perform in-place UID / GID
> namespace mappings in the xattr values. Filesystems then again check for
> the same xattr names to handle those attributes, almost always using the
> standard posix_acl_{access,default}_xattr_handler handlers. This is
> unnecessary overhead; move the namespace conversion into the xattr
> handlers instead.
>
> For filesystems that use the POSIX ACL xattr handlers, no change is
> required. Filesystems that don't use those handlers (cifs and lustre)
> need to take care of the namespace mapping themselves now.
>
> The only user left of the posix_acl_fix_xattr_{from,to}_user helpers is
> lustre, so this patch moves them into lustre.
>
> Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
> ---
>
> I'm reasonably confident about the core and cifs changes in this patch.
> The lustre code is pretty weird though, so could I please get a careful
> review on the changes there?
>
> Thanks,
> Andreas
>
> drivers/staging/lustre/lustre/llite/Makefile | 1 +
> .../staging/lustre/lustre/llite/llite_internal.h | 3 ++
> drivers/staging/lustre/lustre/llite/posix_acl.c | 62 ++++++++++++++++++++++
> drivers/staging/lustre/lustre/llite/xattr.c | 8 ++-
> fs/cifs/cifssmb.c | 41 ++++++++++----
> fs/posix_acl.c | 62 +---------------------
> fs/xattr.c | 7 ---
> include/linux/posix_acl_xattr.h | 12 -----
> 8 files changed, 107 insertions(+), 89 deletions(-)
> create mode 100644 drivers/staging/lustre/lustre/llite/posix_acl.c
>
> diff --git a/drivers/staging/lustre/lustre/llite/Makefile b/drivers/staging/lustre/lustre/llite/Makefile
> index 2ce10ff..67125f8 100644
> --- a/drivers/staging/lustre/lustre/llite/Makefile
> +++ b/drivers/staging/lustre/lustre/llite/Makefile
> @@ -7,5 +7,6 @@ lustre-y := dcache.o dir.o file.o llite_close.o llite_lib.o llite_nfs.o \
> glimpse.o lcommon_cl.o lcommon_misc.o \
> vvp_dev.o vvp_page.o vvp_lock.o vvp_io.o vvp_object.o vvp_req.o \
> lproc_llite.o
> +lustre-$(CONFIG_FS_POSIX_ACL) += posix_acl.o
>
> llite_lloop-y := lloop.o
> diff --git a/drivers/staging/lustre/lustre/llite/llite_internal.h b/drivers/staging/lustre/lustre/llite/llite_internal.h
> index ce1f949..d454dfb 100644
> --- a/drivers/staging/lustre/lustre/llite/llite_internal.h
> +++ b/drivers/staging/lustre/lustre/llite/llite_internal.h
> @@ -1402,4 +1402,7 @@ int cl_local_size(struct inode *inode);
> __u64 cl_fid_build_ino(const struct lu_fid *fid, int api32);
> __u32 cl_fid_build_gen(const struct lu_fid *fid);
>
> +void posix_acl_fix_xattr_from_user(void *value, size_t size);
> +void posix_acl_fix_xattr_to_user(void *value, size_t size);
> +
> #endif /* LLITE_INTERNAL_H */
> diff --git a/drivers/staging/lustre/lustre/llite/posix_acl.c b/drivers/staging/lustre/lustre/llite/posix_acl.c
> new file mode 100644
> index 0000000..4fabd0f
> --- /dev/null
> +++ b/drivers/staging/lustre/lustre/llite/posix_acl.c
> @@ -0,0 +1,62 @@
> +#include <linux/kernel.h>
> +#include <linux/fs.h>
> +#include <linux/posix_acl_xattr.h>
> +#include <linux/user_namespace.h>
> +
> +/*
> + * Fix up the uids and gids in posix acl extended attributes in place.
> + */
> +static void posix_acl_fix_xattr_userns(
> + struct user_namespace *to, struct user_namespace *from,
> + void *value, size_t size)
> +{
> + posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
> + posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
> + int count;
> + kuid_t uid;
> + kgid_t gid;
> +
> + if (!value)
> + return;
> + if (size < sizeof(posix_acl_xattr_header))
> + return;
> + if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
> + return;
> +
> + count = posix_acl_xattr_count(size);
> + if (count < 0)
> + return;
> + if (count == 0)
> + return;
> +
> + for (end = entry + count; entry != end; entry++) {
> + switch(le16_to_cpu(entry->e_tag)) {
> + case ACL_USER:
> + uid = make_kuid(from, le32_to_cpu(entry->e_id));
> + entry->e_id = cpu_to_le32(from_kuid(to, uid));
> + break;
> + case ACL_GROUP:
> + gid = make_kgid(from, le32_to_cpu(entry->e_id));
> + entry->e_id = cpu_to_le32(from_kgid(to, gid));
> + break;
> + default:
> + break;
> + }
> + }
> +}
> +
> +void posix_acl_fix_xattr_from_user(void *value, size_t size)
> +{
> + struct user_namespace *user_ns = current_user_ns();
> + if (user_ns == &init_user_ns)
> + return;
> + posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size);
> +}
> +
> +void posix_acl_fix_xattr_to_user(void *value, size_t size)
> +{
> + struct user_namespace *user_ns = current_user_ns();
> + if (user_ns == &init_user_ns)
> + return;
> + posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size);
> +}
> diff --git a/drivers/staging/lustre/lustre/llite/xattr.c b/drivers/staging/lustre/lustre/llite/xattr.c
> index ed4de04..c721b44 100644
> --- a/drivers/staging/lustre/lustre/llite/xattr.c
> +++ b/drivers/staging/lustre/lustre/llite/xattr.c
> @@ -144,6 +144,9 @@ int ll_setxattr_common(struct inode *inode, const char *name,
> return -EOPNOTSUPP;
>
> #ifdef CONFIG_FS_POSIX_ACL
> + if (xattr_type == XATTR_ACL_ACCESS_T ||
> + xattr_type == XATTR_ACL_DEFAULT_T)
> + posix_acl_fix_xattr_from_user((void *)value, size);
> if (sbi->ll_flags & LL_SBI_RMT_CLIENT &&
> (xattr_type == XATTR_ACL_ACCESS_T ||
> xattr_type == XATTR_ACL_DEFAULT_T)) {
> @@ -348,7 +351,7 @@ int ll_getxattr_common(struct inode *inode, const char *name,
> if (!acl)
> return -ENODATA;
>
> - rc = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
> + rc = posix_acl_to_xattr(current_user_ns(), acl, buffer, size);
> posix_acl_release(acl);
> return rc;
> }
> @@ -436,6 +439,9 @@ getxattr_nocache:
> goto out;
> }
> }
> + if (rc >= 0 && (xattr_type == XATTR_ACL_ACCESS_T ||
> + xattr_type == XATTR_ACL_DEFAULT_T))
> + posix_acl_fix_xattr_to_user(buffer, rc);
> #endif
>
> out_xattr:
> diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
> index d47197e..9dc001f 100644
> --- a/fs/cifs/cifssmb.c
> +++ b/fs/cifs/cifssmb.c
> @@ -3337,10 +3337,25 @@ CIFSSMB_set_compression(const unsigned int xid, struct cifs_tcon *tcon,
> static void cifs_convert_ace(posix_acl_xattr_entry *ace,
> struct cifs_posix_ace *cifs_ace)
> {
> + u32 cifs_id, id = -1;
> +
> /* u8 cifs fields do not need le conversion */
> ace->e_perm = cpu_to_le16(cifs_ace->cifs_e_perm);
> ace->e_tag = cpu_to_le16(cifs_ace->cifs_e_tag);
> - ace->e_id = cpu_to_le32(le64_to_cpu(cifs_ace->cifs_uid));
> + switch(cifs_ace->cifs_e_tag) {
> + case ACL_USER:
> + cifs_id = le64_to_cpu(cifs_ace->cifs_uid);
> + id = from_kuid(current_user_ns(),
> + make_kuid(&init_user_ns, cifs_id));
> + break;
> +
> + case ACL_GROUP:
> + cifs_id = le64_to_cpu(cifs_ace->cifs_uid);
> + id = from_kgid(current_user_ns(),
> + make_kgid(&init_user_ns, cifs_id));
> + break;
> + }
> + ace->e_id = cpu_to_le32(id);
> /*
> cifs_dbg(FYI, "perm %d tag %d id %d\n",
> ace->e_perm, ace->e_tag, ace->e_id);
> @@ -3408,21 +3423,29 @@ static int cifs_copy_posix_acl(char *trgt, char *src, const int buflen,
> static __u16 convert_ace_to_cifs_ace(struct cifs_posix_ace *cifs_ace,
> const posix_acl_xattr_entry *local_ace)
> {
> - __u16 rc = 0; /* 0 = ACL converted ok */
> + u32 cifs_id = -1, id;
>
> cifs_ace->cifs_e_perm = le16_to_cpu(local_ace->e_perm);
> cifs_ace->cifs_e_tag = le16_to_cpu(local_ace->e_tag);
> - /* BB is there a better way to handle the large uid? */
> - if (local_ace->e_id == cpu_to_le32(-1)) {
> - /* Probably no need to le convert -1 on any arch but can not hurt */
> - cifs_ace->cifs_uid = cpu_to_le64(-1);
> - } else
> - cifs_ace->cifs_uid = cpu_to_le64(le32_to_cpu(local_ace->e_id));
> + switch(cifs_ace->cifs_e_tag) {
> + case ACL_USER:
> + id = le32_to_cpu(local_ace->e_id);
> + cifs_id = from_kuid(&init_user_ns,
> + make_kuid(current_user_ns(), id));
> + break;
> +
> + case ACL_GROUP:
> + id = le32_to_cpu(local_ace->e_id);
> + cifs_id = from_kgid(&init_user_ns,
> + make_kgid(current_user_ns(), id));
> + break;
> + }
> + cifs_ace->cifs_uid = cpu_to_le64(cifs_id);
> /*
> cifs_dbg(FYI, "perm %d tag %d id %d\n",
> ace->e_perm, ace->e_tag, ace->e_id);
> */
> - return rc;
> + return 0;
> }
>
> /* Convert ACL from local Linux POSIX xattr to CIFS POSIX ACL wire format */
> diff --git a/fs/posix_acl.c b/fs/posix_acl.c
> index 2c60f17..fca281c 100644
> --- a/fs/posix_acl.c
> +++ b/fs/posix_acl.c
> @@ -627,64 +627,6 @@ no_mem:
> EXPORT_SYMBOL_GPL(posix_acl_create);
>
> /*
> - * Fix up the uids and gids in posix acl extended attributes in place.
> - */
> -static void posix_acl_fix_xattr_userns(
> - struct user_namespace *to, struct user_namespace *from,
> - void *value, size_t size)
> -{
> - posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
> - posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
> - int count;
> - kuid_t uid;
> - kgid_t gid;
> -
> - if (!value)
> - return;
> - if (size < sizeof(posix_acl_xattr_header))
> - return;
> - if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
> - return;
> -
> - count = posix_acl_xattr_count(size);
> - if (count < 0)
> - return;
> - if (count == 0)
> - return;
> -
> - for (end = entry + count; entry != end; entry++) {
> - switch(le16_to_cpu(entry->e_tag)) {
> - case ACL_USER:
> - uid = make_kuid(from, le32_to_cpu(entry->e_id));
> - entry->e_id = cpu_to_le32(from_kuid(to, uid));
> - break;
> - case ACL_GROUP:
> - gid = make_kgid(from, le32_to_cpu(entry->e_id));
> - entry->e_id = cpu_to_le32(from_kgid(to, gid));
> - break;
> - default:
> - break;
> - }
> - }
> -}
> -
> -void posix_acl_fix_xattr_from_user(void *value, size_t size)
> -{
> - struct user_namespace *user_ns = current_user_ns();
> - if (user_ns == &init_user_ns)
> - return;
> - posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size);
> -}
> -
> -void posix_acl_fix_xattr_to_user(void *value, size_t size)
> -{
> - struct user_namespace *user_ns = current_user_ns();
> - if (user_ns == &init_user_ns)
> - return;
> - posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size);
> -}
> -
> -/*
> * Convert from extended attribute to in-memory representation.
> */
> struct posix_acl *
> @@ -814,7 +756,7 @@ posix_acl_xattr_get(const struct xattr_handler *handler,
> if (acl == NULL)
> return -ENODATA;
>
> - error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
> + error = posix_acl_to_xattr(current_user_ns(), acl, value, size);
> posix_acl_release(acl);
>
> return error;
> @@ -840,7 +782,7 @@ posix_acl_xattr_set(const struct xattr_handler *handler,
> return -EPERM;
>
> if (value) {
> - acl = posix_acl_from_xattr(&init_user_ns, value, size);
> + acl = posix_acl_from_xattr(current_user_ns(), value, size);
> if (IS_ERR(acl))
> return PTR_ERR(acl);
>
> diff --git a/fs/xattr.c b/fs/xattr.c
> index b11945e..b648b05 100644
> --- a/fs/xattr.c
> +++ b/fs/xattr.c
> @@ -20,7 +20,6 @@
> #include <linux/fsnotify.h>
> #include <linux/audit.h>
> #include <linux/vmalloc.h>
> -#include <linux/posix_acl_xattr.h>
>
> #include <asm/uaccess.h>
>
> @@ -329,9 +328,6 @@ setxattr(struct dentry *d, const char __user *name, const void __user *value,
> error = -EFAULT;
> goto out;
> }
> - if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
> - (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))
> - posix_acl_fix_xattr_from_user(kvalue, size);
> }
>
> error = vfs_setxattr(d, kname, kvalue, size, flags);
> @@ -426,9 +422,6 @@ getxattr(struct dentry *d, const char __user *name, void __user *value,
>
> error = vfs_getxattr(d, kname, kvalue, 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(kvalue, size);
> if (size && copy_to_user(value, kvalue, error))
> error = -EFAULT;
> } else if (error == -ERANGE && size >= XATTR_SIZE_MAX) {
> diff --git a/include/linux/posix_acl_xattr.h b/include/linux/posix_acl_xattr.h
> index e5e8ec4..9789aba 100644
> --- a/include/linux/posix_acl_xattr.h
> +++ b/include/linux/posix_acl_xattr.h
> @@ -48,18 +48,6 @@ posix_acl_xattr_count(size_t size)
> return size / sizeof(posix_acl_xattr_entry);
> }
>
> -#ifdef CONFIG_FS_POSIX_ACL
> -void posix_acl_fix_xattr_from_user(void *value, size_t size);
> -void posix_acl_fix_xattr_to_user(void *value, size_t size);
> -#else
> -static inline void posix_acl_fix_xattr_from_user(void *value, size_t size)
> -{
> -}
> -static inline void posix_acl_fix_xattr_to_user(void *value, size_t size)
> -{
> -}
> -#endif
> -
> struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns,
> const void *value, size_t size);
> int posix_acl_to_xattr(struct user_namespace *user_ns,
> --
> 2.5.5
>
> --
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--
Thanks,
Steve
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