staging: lustre: llite: basic port to xattr_handler API

Port the xattr functionality to the new xattr_handler API.
This is smallest changes needed to move to this new API. The
function ll_removexattr can be replaced by generic_removexattr
as well since it also uses the xattr_handler set xattr backend.
To tell the difference between the two cases we test the flag
passed in for XATTR_REPLACE. The ll_getxattr function is
replaced by the generic_getxattr function.

Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

6 files changed, 141 insertions, 87 deletions

diff --git a/drivers/staging/lustre/lustre/llite/file.c b/drivers/staging/lustre/lustre/llite/file.c
index 57281b9e31ff..58a7401046e0 100644
--- a/drivers/staging/lustre/lustre/llite/file.c
+++ b/drivers/staging/lustre/lustre/llite/file.c
@@ -3213,10 +3213,10 @@ const struct inode_operations ll_file_inode_operations = {
         .setattr        = ll_setattr,
         .getattr        = ll_getattr,
         .permission     = ll_inode_permission,
-        .setxattr       = ll_setxattr,
-        .getxattr       = ll_getxattr,
+        .setxattr       = generic_setxattr,
+        .getxattr       = generic_getxattr,
         .listxattr      = ll_listxattr,
-        .removexattr    = ll_removexattr,
+        .removexattr    = generic_removexattr,
         .fiemap         = ll_fiemap,
         .get_acl        = ll_get_acl,
 };
diff --git a/drivers/staging/lustre/lustre/llite/llite_internal.h b/drivers/staging/lustre/lustre/llite/llite_internal.h
index 4d6d589a1677..27d3f7706d44 100644
--- a/drivers/staging/lustre/lustre/llite/llite_internal.h
+++ b/drivers/staging/lustre/lustre/llite/llite_internal.h
@@ -42,6 +42,7 @@
 #include "../include/lustre_mdc.h"
 #include "../include/lustre_intent.h"
 #include <linux/compat.h>
+#include <linux/xattr.h>
 #include <linux/posix_acl_xattr.h>
 #include "vvp_internal.h"
 
@@ -933,12 +934,9 @@ static inline __u64 ll_file_maxbytes(struct inode *inode)
 }
 
 /* llite/xattr.c */
-int ll_setxattr(struct dentry *dentry, struct inode *inode,
-                const char *name, const void *value, size_t size, int flags);
-ssize_t ll_getxattr(struct dentry *dentry, struct inode *inode,
-                    const char *name, void *buffer, size_t size);
+extern const struct xattr_handler *ll_xattr_handlers[];
+
 ssize_t ll_listxattr(struct dentry *dentry, char *buffer, size_t size);
-int ll_removexattr(struct dentry *dentry, const char *name);
 
 /**
  * Common IO arguments for various VFS I/O interfaces.
diff --git a/drivers/staging/lustre/lustre/llite/llite_lib.c b/drivers/staging/lustre/lustre/llite/llite_lib.c
index 546063e728db..75d568f5bb90 100644
--- a/drivers/staging/lustre/lustre/llite/llite_lib.c
+++ b/drivers/staging/lustre/lustre/llite/llite_lib.c
@@ -418,6 +418,7 @@ static int client_common_fill_super(struct super_block *sb, char *md, char *dt,
         CDEBUG(D_SUPER, "rootfid "DFID"\n", PFID(&sbi->ll_root_fid));
 
         sb->s_op = &lustre_super_operations;
+        sb->s_xattr = ll_xattr_handlers;
 #if THREAD_SIZE >= 8192 /*b=17630*/
         sb->s_export_op = &lustre_export_operations;
 #endif
diff --git a/drivers/staging/lustre/lustre/llite/namei.c b/drivers/staging/lustre/lustre/llite/namei.c
index 3664bfd0178b..1e75f5b09c31 100644
--- a/drivers/staging/lustre/lustre/llite/namei.c
+++ b/drivers/staging/lustre/lustre/llite/namei.c
@@ -1101,10 +1101,10 @@ const struct inode_operations ll_dir_inode_operations = {
         .setattr            = ll_setattr,
         .getattr            = ll_getattr,
         .permission      = ll_inode_permission,
-        .setxattr          = ll_setxattr,
-        .getxattr          = ll_getxattr,
+        .setxattr          = generic_setxattr,
+        .getxattr          = generic_getxattr,
         .listxattr        = ll_listxattr,
-        .removexattr    = ll_removexattr,
+        .removexattr    = generic_removexattr,
         .get_acl            = ll_get_acl,
 };
 
@@ -1112,9 +1112,9 @@ const struct inode_operations ll_special_inode_operations = {
         .setattr        = ll_setattr,
         .getattr        = ll_getattr,
         .permission     = ll_inode_permission,
-        .setxattr       = ll_setxattr,
-        .getxattr       = ll_getxattr,
+        .setxattr       = generic_setxattr,
+        .getxattr       = generic_getxattr,
         .listxattr      = ll_listxattr,
-        .removexattr    = ll_removexattr,
+        .removexattr    = generic_removexattr,
         .get_acl            = ll_get_acl,
 };
diff --git a/drivers/staging/lustre/lustre/llite/symlink.c b/drivers/staging/lustre/lustre/llite/symlink.c
index 8c8bdfe1ad71..4601be94dd22 100644
--- a/drivers/staging/lustre/lustre/llite/symlink.c
+++ b/drivers/staging/lustre/lustre/llite/symlink.c
@@ -155,8 +155,8 @@ const struct inode_operations ll_fast_symlink_inode_operations = {
         .get_link       = ll_get_link,
         .getattr        = ll_getattr,
         .permission     = ll_inode_permission,
-        .setxattr       = ll_setxattr,
-        .getxattr       = ll_getxattr,
+        .setxattr       = generic_setxattr,
+        .getxattr       = generic_getxattr,
         .listxattr      = ll_listxattr,
-        .removexattr    = ll_removexattr,
+        .removexattr    = generic_removexattr,
 };
diff --git a/drivers/staging/lustre/lustre/llite/xattr.c b/drivers/staging/lustre/lustre/llite/xattr.c
index a034a5f61d22..a02b80269b5c 100644
--- a/drivers/staging/lustre/lustre/llite/xattr.c
+++ b/drivers/staging/lustre/lustre/llite/xattr.c
@@ -99,46 +99,57 @@ int xattr_type_filter(struct ll_sb_info *sbi, int xattr_type)
         return 0;
 }
 
-static
-int ll_setxattr_common(struct inode *inode, const char *name,
-                       const void *value, size_t size,
-                       int flags, __u64 valid)
+static int
+ll_xattr_set_common(const struct xattr_handler *handler,
+                    struct dentry *dentry, struct inode *inode,
+                    const char *name, const void *value, size_t size,
+                    int flags)
 {
+        char fullname[strlen(handler->prefix) + strlen(name) + 1];
         struct ll_sb_info *sbi = ll_i2sbi(inode);
         struct ptlrpc_request *req = NULL;
-        int xattr_type, rc;
         const char *pv = value;
+        __u64 valid;
+        int rc;
 
-        xattr_type = get_xattr_type(name);
-        rc = xattr_type_filter(sbi, xattr_type);
+        if (flags == XATTR_REPLACE) {
+                ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_REMOVEXATTR, 1);
+                valid = OBD_MD_FLXATTRRM;
+        } else {
+                ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_SETXATTR, 1);
+                valid = OBD_MD_FLXATTR;
+        }
+
+        rc = xattr_type_filter(sbi, handler->flags);
         if (rc)
                 return rc;
 
-        if ((xattr_type == XATTR_ACL_ACCESS_T ||
-             xattr_type == XATTR_ACL_DEFAULT_T) &&
+        if ((handler->flags == XATTR_ACL_ACCESS_T ||
+             handler->flags == XATTR_ACL_DEFAULT_T) &&
             !inode_owner_or_capable(inode))
                 return -EPERM;
 
         /* b10667: ignore lustre special xattr for now */
-        if ((xattr_type == XATTR_TRUSTED_T && strcmp(name, "trusted.lov") == 0) ||
-            (xattr_type == XATTR_LUSTRE_T && strcmp(name, "lustre.lov") == 0))
+        if ((handler->flags == XATTR_TRUSTED_T && !strcmp(name, "lov")) ||
+            (handler->flags == XATTR_LUSTRE_T && !strcmp(name, "lov")))
                 return 0;
 
         /* b15587: ignore security.capability xattr for now */
-        if ((xattr_type == XATTR_SECURITY_T &&
-             strcmp(name, "security.capability") == 0))
+        if ((handler->flags == XATTR_SECURITY_T &&
+             !strcmp(name, "capability")))
                 return 0;
 
         /* LU-549:  Disable security.selinux when selinux is disabled */
-        if (xattr_type == XATTR_SECURITY_T && !selinux_is_enabled() &&
-            strcmp(name, "security.selinux") == 0)
+        if (handler->flags == XATTR_SECURITY_T && !selinux_is_enabled() &&
+            strcmp(name, "selinux") == 0)
                 return -EOPNOTSUPP;
 
+        sprintf(fullname, "%s%s\n", handler->prefix, name);
         rc = md_setxattr(sbi->ll_md_exp, ll_inode2fid(inode),
-                         valid, name, pv, size, 0, flags,
+                         valid, fullname, pv, size, 0, flags,
                          ll_i2suppgid(inode), &req);
         if (rc) {
-                if (rc == -EOPNOTSUPP && xattr_type == XATTR_USER_T) {
+                if (rc == -EOPNOTSUPP && handler->flags == XATTR_USER_T) {
                         LCONSOLE_INFO("Disabling user_xattr feature because it is not supported on the server\n");
                         sbi->ll_flags &= ~LL_SBI_USER_XATTR;
                 }
@@ -149,8 +160,10 @@ int ll_setxattr_common(struct inode *inode, const char *name,
         return 0;
 }
 
-int ll_setxattr(struct dentry *dentry, struct inode *inode,
-                const char *name, const void *value, size_t size, int flags)
+static int ll_xattr_set(const struct xattr_handler *handler,
+                        struct dentry *dentry, struct inode *inode,
+                        const char *name, const void *value, size_t size,
+                        int flags)
 {
         LASSERT(inode);
         LASSERT(name);
@@ -158,20 +171,24 @@ int ll_setxattr(struct dentry *dentry, struct inode *inode,
         CDEBUG(D_VFSTRACE, "VFS Op:inode="DFID"(%p), xattr %s\n",
                PFID(ll_inode2fid(inode)), inode, name);
 
-        ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_SETXATTR, 1);
-
-        if ((strncmp(name, XATTR_TRUSTED_PREFIX,
-                     sizeof(XATTR_TRUSTED_PREFIX) - 1) == 0 &&
-             strcmp(name + sizeof(XATTR_TRUSTED_PREFIX) - 1, "lov") == 0) ||
-            (strncmp(name, XATTR_LUSTRE_PREFIX,
-                     sizeof(XATTR_LUSTRE_PREFIX) - 1) == 0 &&
-             strcmp(name + sizeof(XATTR_LUSTRE_PREFIX) - 1, "lov") == 0)) {
+        if (!strcmp(name, "lov")) {
                 struct lov_user_md *lump = (struct lov_user_md *)value;
+                int op_type = flags == XATTR_REPLACE ? LPROC_LL_REMOVEXATTR :
+                                                       LPROC_LL_SETXATTR;
                 int rc = 0;
 
+                ll_stats_ops_tally(ll_i2sbi(inode), op_type, 1);
+
                 if (size != 0 && size < sizeof(struct lov_user_md))
                         return -EINVAL;
 
+                /*
+                 * It is possible to set an xattr to a "" value of zero size.
+                 * For this case we are going to treat it as a removal.
+                 */
+                if (!size && lump)
+                        lump = NULL;
+
                 /* Attributes that are saved via getxattr will always have
                  * the stripe_offset as 0.  Instead, the MDS should be
                  * allowed to pick the starting OST index.   b=17846
@@ -194,27 +211,13 @@ int ll_setxattr(struct dentry *dentry, struct inode *inode,
 
                 return rc;
 
-        } else if (strcmp(name, XATTR_NAME_LMA) == 0 ||
-                   strcmp(name, XATTR_NAME_LINK) == 0)
+        } else if (!strcmp(name, "lma") || !strcmp(name, "link")) {
+                ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_SETXATTR, 1);
                 return 0;
+        }
 
-        return ll_setxattr_common(inode, name, value, size, flags,
-                                  OBD_MD_FLXATTR);
-}
-
-int ll_removexattr(struct dentry *dentry, const char *name)
-{
-        struct inode *inode = d_inode(dentry);
-
-        LASSERT(inode);
-        LASSERT(name);
-
-        CDEBUG(D_VFSTRACE, "VFS Op:inode="DFID"(%p), xattr %s\n",
-               PFID(ll_inode2fid(inode)), inode, name);
-
-        ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_REMOVEXATTR, 1);
-        return ll_setxattr_common(inode, name, NULL, 0, 0,
-                                  OBD_MD_FLXATTRRM);
+        return ll_xattr_set_common(handler, dentry, inode, name, value, size,
+                                   flags);
 }
 
 static int
@@ -300,30 +303,31 @@ out:
         return rc;
 }
 
-static
-int ll_getxattr_common(struct inode *inode, const char *name,
-                       void *buffer, size_t size)
+static int ll_xattr_get_common(const struct xattr_handler *handler,
+                               struct dentry *dentry, struct inode *inode,
+                               const char *name, void *buffer, size_t size)
 {
+        char fullname[strlen(handler->prefix) + strlen(name) + 1];
         struct ll_sb_info *sbi = ll_i2sbi(inode);
-        int xattr_type, rc;
         struct ll_inode_info *lli = ll_i2info(inode);
+        int rc;
 
         CDEBUG(D_VFSTRACE, "VFS Op:inode="DFID"(%p)\n",
                PFID(ll_inode2fid(inode)), inode);
 
-        xattr_type = get_xattr_type(name);
-        rc = xattr_type_filter(sbi, xattr_type);
+        ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_GETXATTR, 1);
+
+        rc = xattr_type_filter(sbi, handler->flags);
         if (rc)
                 return rc;
 
         /* b15587: ignore security.capability xattr for now */
-        if ((xattr_type == XATTR_SECURITY_T &&
-             strcmp(name, "security.capability") == 0))
+        if ((handler->flags == XATTR_SECURITY_T && !strcmp(name, "capability")))
                 return -ENODATA;
 
         /* LU-549:  Disable security.selinux when selinux is disabled */
-        if (xattr_type == XATTR_SECURITY_T && !selinux_is_enabled() &&
-            strcmp(name, "security.selinux") == 0)
+        if (handler->flags == XATTR_SECURITY_T && !selinux_is_enabled() &&
+            !strcmp(name, "selinux"))
                 return -EOPNOTSUPP;
 
 #ifdef CONFIG_FS_POSIX_ACL
@@ -331,7 +335,7 @@ int ll_getxattr_common(struct inode *inode, const char *name,
          * we just have path resolution to the target inode, so we have great
          * chance that cached ACL is uptodate.
          */
-        if (xattr_type == XATTR_ACL_ACCESS_T) {
+        if (handler->flags == XATTR_ACL_ACCESS_T) {
                 struct posix_acl *acl;
 
                 spin_lock(&lli->lli_lock);
@@ -345,15 +349,17 @@ int ll_getxattr_common(struct inode *inode, const char *name,
                 posix_acl_release(acl);
                 return rc;
         }
-        if (xattr_type == XATTR_ACL_DEFAULT_T && !S_ISDIR(inode->i_mode))
+        if (handler->flags == XATTR_ACL_DEFAULT_T && !S_ISDIR(inode->i_mode))
                 return -ENODATA;
 #endif
-        return ll_xattr_list(inode, name, xattr_type, buffer, size,
+        sprintf(fullname, "%s%s\n", handler->prefix, name);
+        return ll_xattr_list(inode, fullname, handler->flags, buffer, size,
                              OBD_MD_FLXATTR);
 }
 
-ssize_t ll_getxattr(struct dentry *dentry, struct inode *inode,
-                    const char *name, void *buffer, size_t size)
+static int ll_xattr_get(const struct xattr_handler *handler,
+                        struct dentry *dentry, struct inode *inode,
+                        const char *name, void *buffer, size_t size)
 {
         LASSERT(inode);
         LASSERT(name);
@@ -361,20 +367,15 @@ ssize_t ll_getxattr(struct dentry *dentry, struct inode *inode,
         CDEBUG(D_VFSTRACE, "VFS Op:inode="DFID"(%p), xattr %s\n",
                PFID(ll_inode2fid(inode)), inode, name);
 
-        ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_GETXATTR, 1);
-
-        if ((strncmp(name, XATTR_TRUSTED_PREFIX,
-                     sizeof(XATTR_TRUSTED_PREFIX) - 1) == 0 &&
-             strcmp(name + sizeof(XATTR_TRUSTED_PREFIX) - 1, "lov") == 0) ||
-            (strncmp(name, XATTR_LUSTRE_PREFIX,
-                     sizeof(XATTR_LUSTRE_PREFIX) - 1) == 0 &&
-             strcmp(name + sizeof(XATTR_LUSTRE_PREFIX) - 1, "lov") == 0)) {
+        if (!strcmp(name, "lov")) {
                 struct lov_stripe_md *lsm;
                 struct lov_user_md *lump;
                 struct lov_mds_md *lmm = NULL;
                 struct ptlrpc_request *request = NULL;
                 int rc = 0, lmmsize = 0;
 
+                ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_GETXATTR, 1);
+
                 if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
                         return -ENODATA;
 
@@ -440,7 +441,7 @@ out:
                 return rc;
         }
 
-        return ll_getxattr_common(inode, name, buffer, size);
+        return ll_xattr_get_common(handler, dentry, inode, name, buffer, size);
 }
 
 ssize_t ll_listxattr(struct dentry *dentry, char *buffer, size_t size)
@@ -520,3 +521,57 @@ out:
 
         return rc;
 }
+
+static const struct xattr_handler ll_user_xattr_handler = {
+        .prefix = XATTR_USER_PREFIX,
+        .flags = XATTR_USER_T,
+        .get = ll_xattr_get_common,
+        .set = ll_xattr_set_common,
+};
+
+static const struct xattr_handler ll_trusted_xattr_handler = {
+        .prefix = XATTR_TRUSTED_PREFIX,
+        .flags = XATTR_TRUSTED_T,
+        .get = ll_xattr_get,
+        .set = ll_xattr_set,
+};
+
+static const struct xattr_handler ll_security_xattr_handler = {
+        .prefix = XATTR_SECURITY_PREFIX,
+        .flags = XATTR_SECURITY_T,
+        .get = ll_xattr_get_common,
+        .set = ll_xattr_set_common,
+};
+
+static const struct xattr_handler ll_acl_access_xattr_handler = {
+        .prefix = XATTR_NAME_POSIX_ACL_ACCESS,
+        .flags = XATTR_ACL_ACCESS_T,
+        .get = ll_xattr_get_common,
+        .set = ll_xattr_set_common,
+};
+
+static const struct xattr_handler ll_acl_default_xattr_handler = {
+        .prefix = XATTR_NAME_POSIX_ACL_DEFAULT,
+        .flags = XATTR_ACL_DEFAULT_T,
+        .get = ll_xattr_get_common,
+        .set = ll_xattr_set_common,
+};
+
+static const struct xattr_handler ll_lustre_xattr_handler = {
+        .prefix = XATTR_LUSTRE_PREFIX,
+        .flags = XATTR_LUSTRE_T,
+        .get = ll_xattr_get,
+        .set = ll_xattr_set,
+};
+
+const struct xattr_handler *ll_xattr_handlers[] = {
+        &ll_user_xattr_handler,
+        &ll_trusted_xattr_handler,
+        &ll_security_xattr_handler,
+#ifdef CONFIG_FS_POSIX_ACL
+        &ll_acl_access_xattr_handler,
+        &ll_acl_default_xattr_handler,
+#endif
+        &ll_lustre_xattr_handler,
+        NULL,
+};