[PATCH 054/124] staging: lustre: llite: Add ioctl to get parent fids from link EA.

From: James Simmons
Date: Sun Sep 18 2016 - 16:59:53 EST


From: Henri Doreau <henri.doreau@xxxxxx>

Added LL_IOC_GETPARENT to retrieve the <parent_fid>/name(s) of a given
entry, based on its link EA. This saves multiple calls to
path2fid/fid2path.

Merged with second later patch that does various cleanups.
Avoid unneeded allocation. Get read-only attributes from the user
getparent structure and write the modified attributes only, instead
of populating a whole structure in kernel and copying it back.

Signed-off-by: Thomas Leibovici <thomas.leibovici@xxxxxx>
Signed-off-by: Henri Doreau <henri.doreau@xxxxxx>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3613
Reviewed-on: http://review.whamcloud.com/7069
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5837
Reviewed-on: http://review.whamcloud.com/12527
Reviewed-by: Ned Bass <bass6@xxxxxxxx>
Reviewed-by: frank zago <fzago@xxxxxxxx>
Reviewed-by: John L. Hammond <john.hammond@xxxxxxxxx>
Reviewed-by: Oleg Drokin <oleg.drokin@xxxxxxxxx>
Signed-off-by: James Simmons <jsimmons@xxxxxxxxxxxxx>
---
.../lustre/lustre/include/lustre/lustre_idl.h | 8 ++
.../lustre/lustre/include/lustre/lustre_user.h | 1 +
drivers/staging/lustre/lustre/llite/dir.c | 2 +
drivers/staging/lustre/lustre/llite/file.c | 2 +
.../staging/lustre/lustre/llite/llite_internal.h | 13 ++
drivers/staging/lustre/lustre/llite/llite_lib.c | 125 ++++++++++++++++++++
drivers/staging/lustre/lustre/llite/xattr.c | 10 +--
7 files changed, 152 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h b/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
index 2dc550a..0cc47bc 100644
--- a/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
+++ b/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
@@ -3468,6 +3468,14 @@ struct getinfo_fid2path {

void lustre_swab_fid2path(struct getinfo_fid2path *gf);

+/** path2parent request/reply structures */
+struct getparent {
+ struct lu_fid gp_fid; /**< parent FID */
+ __u32 gp_linkno; /**< hardlink number */
+ __u32 gp_name_size; /**< size of the name field */
+ char gp_name[0]; /**< zero-terminated link name */
+} __packed;
+
enum {
LAYOUT_INTENT_ACCESS = 0,
LAYOUT_INTENT_READ = 1,
diff --git a/drivers/staging/lustre/lustre/include/lustre/lustre_user.h b/drivers/staging/lustre/lustre/include/lustre/lustre_user.h
index cc0a786..08ac6e4 100644
--- a/drivers/staging/lustre/lustre/include/lustre/lustre_user.h
+++ b/drivers/staging/lustre/lustre/include/lustre/lustre_user.h
@@ -245,6 +245,7 @@ struct ost_id {
#define LL_IOC_LMV_SET_DEFAULT_STRIPE _IOWR('f', 246, struct lmv_user_md)
#define LL_IOC_MIGRATE _IOR('f', 247, int)
#define LL_IOC_FID2MDTIDX _IOWR('f', 248, struct lu_fid)
+#define LL_IOC_GETPARENT _IOWR('f', 249, struct getparent)

/* Lease types for use as arg and return of LL_IOC_{GET,SET}_LEASE ioctl. */
enum ll_lease_type {
diff --git a/drivers/staging/lustre/lustre/llite/dir.c b/drivers/staging/lustre/lustre/llite/dir.c
index 234095e..705de1c 100644
--- a/drivers/staging/lustre/lustre/llite/dir.c
+++ b/drivers/staging/lustre/lustre/llite/dir.c
@@ -1562,6 +1562,8 @@ out_quotactl:
return rc;
case OBD_IOC_FID2PATH:
return ll_fid2path(inode, (void __user *)arg);
+ case LL_IOC_GETPARENT:
+ return ll_getparent(file, (void __user *)arg);
case LL_IOC_FID2MDTIDX: {
struct obd_export *exp = ll_i2mdexp(inode);
struct lu_fid fid;
diff --git a/drivers/staging/lustre/lustre/llite/file.c b/drivers/staging/lustre/lustre/llite/file.c
index 127d0e0..45acc5d 100644
--- a/drivers/staging/lustre/lustre/llite/file.c
+++ b/drivers/staging/lustre/lustre/llite/file.c
@@ -2362,6 +2362,8 @@ ll_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

return 0;
}
+ case LL_IOC_GETPARENT:
+ return ll_getparent(file, (struct getparent __user *)arg);
case OBD_IOC_FID2PATH:
return ll_fid2path(inode, (void __user *)arg);
case LL_IOC_DATA_VERSION: {
diff --git a/drivers/staging/lustre/lustre/llite/llite_internal.h b/drivers/staging/lustre/lustre/llite/llite_internal.h
index fc707c2..1cc427c 100644
--- a/drivers/staging/lustre/lustre/llite/llite_internal.h
+++ b/drivers/staging/lustre/lustre/llite/llite_internal.h
@@ -36,6 +36,7 @@
#include "../include/lustre_ver.h"
#include "../include/lustre_disk.h" /* for s2sbi */
#include "../include/lustre_eacl.h"
+#include "../include/lustre_linkea.h"

/* for struct cl_lock_descr and struct cl_io */
#include "../include/cl_object.h"
@@ -1038,7 +1039,17 @@ static inline __u64 ll_file_maxbytes(struct inode *inode)
/* llite/xattr.c */
extern const struct xattr_handler *ll_xattr_handlers[];

+#define XATTR_USER_T 1
+#define XATTR_TRUSTED_T 2
+#define XATTR_SECURITY_T 3
+#define XATTR_ACL_ACCESS_T 4
+#define XATTR_ACL_DEFAULT_T 5
+#define XATTR_LUSTRE_T 6
+#define XATTR_OTHER_T 7
+
ssize_t ll_listxattr(struct dentry *dentry, char *buffer, size_t size);
+int ll_xattr_list(struct inode *inode, const char *name, int type,
+ void *buffer, size_t size, __u64 valid);

/**
* Common IO arguments for various VFS I/O interfaces.
@@ -1399,6 +1410,8 @@ void ll_xattr_fini(void);
int ll_page_sync_io(const struct lu_env *env, struct cl_io *io,
struct cl_page *page, enum cl_req_type crt);

+int ll_getparent(struct file *file, struct getparent __user *arg);
+
/* lcommon_cl.c */
int cl_setattr_ost(struct inode *inode, const struct iattr *attr);

diff --git a/drivers/staging/lustre/lustre/llite/llite_lib.c b/drivers/staging/lustre/lustre/llite/llite_lib.c
index 5792354..5cbce1b 100644
--- a/drivers/staging/lustre/lustre/llite/llite_lib.c
+++ b/drivers/staging/lustre/lustre/llite/llite_lib.c
@@ -2545,3 +2545,128 @@ void ll_compute_rootsquash_state(struct ll_sb_info *sbi)
}
up_write(&squash->rsi_sem);
}
+
+/**
+ * Parse linkea content to extract information about a given hardlink
+ *
+ * \param[in] ldata - Initialized linkea data
+ * \param[in] linkno - Link identifier
+ * \param[out] parent_fid - The entry's parent FID
+ * \param[in] size - Entry name destination buffer
+ *
+ * \retval 0 on success
+ * \retval Appropriate negative error code on failure
+ */
+static int ll_linkea_decode(struct linkea_data *ldata, unsigned int linkno,
+ struct lu_fid *parent_fid, struct lu_name *ln)
+{
+ unsigned int idx;
+ int rc;
+
+ rc = linkea_init(ldata);
+ if (rc < 0)
+ return rc;
+
+ if (linkno >= ldata->ld_leh->leh_reccount)
+ /* beyond last link */
+ return -ENODATA;
+
+ linkea_first_entry(ldata);
+ for (idx = 0; ldata->ld_lee; idx++) {
+ linkea_entry_unpack(ldata->ld_lee, &ldata->ld_reclen, ln,
+ parent_fid);
+ if (idx == linkno)
+ break;
+
+ linkea_next_entry(ldata);
+ }
+
+ if (idx < linkno)
+ return -ENODATA;
+
+ return 0;
+}
+
+/**
+ * Get parent FID and name of an identified link. Operation is performed for
+ * a given link number, letting the caller iterate over linkno to list one or
+ * all links of an entry.
+ *
+ * \param[in] file - File descriptor against which to perform the operation
+ * \param[in,out] arg - User-filled structure containing the linkno to operate
+ * on and the available size. It is eventually filled with
+ * the requested information or left untouched on error
+ *
+ * \retval - 0 on success
+ * \retval - Appropriate negative error code on failure
+ */
+int ll_getparent(struct file *file, struct getparent __user *arg)
+{
+ struct inode *inode = file_inode(file);
+ struct linkea_data *ldata;
+ struct lu_fid parent_fid;
+ struct lu_buf buf = {
+ .lb_buf = NULL,
+ .lb_len = 0
+ };
+ struct lu_name ln;
+ u32 name_size;
+ u32 linkno;
+ int rc;
+
+ if (!capable(CFS_CAP_DAC_READ_SEARCH) &&
+ !(ll_i2sbi(inode)->ll_flags & LL_SBI_USER_FID2PATH))
+ return -EPERM;
+
+ if (get_user(name_size, &arg->gp_name_size))
+ return -EFAULT;
+
+ if (get_user(linkno, &arg->gp_linkno))
+ return -EFAULT;
+
+ if (name_size > PATH_MAX)
+ return -EINVAL;
+
+ ldata = kzalloc(sizeof(*ldata), GFP_NOFS);
+ if (!ldata)
+ return -ENOMEM;
+
+ rc = linkea_data_new(ldata, &buf);
+ if (rc < 0)
+ goto ldata_free;
+
+ rc = ll_xattr_list(inode, XATTR_NAME_LINK, XATTR_TRUSTED_T, buf.lb_buf,
+ buf.lb_len, OBD_MD_FLXATTR);
+ if (rc < 0)
+ goto lb_free;
+
+ rc = ll_linkea_decode(ldata, linkno, &parent_fid, &ln);
+ if (rc < 0)
+ goto lb_free;
+
+ if (ln.ln_namelen >= name_size) {
+ rc = -EOVERFLOW;
+ goto lb_free;
+ }
+
+ if (copy_to_user(&arg->gp_fid, &parent_fid, sizeof(arg->gp_fid))) {
+ rc = -EFAULT;
+ goto lb_free;
+ }
+
+ if (copy_to_user(&arg->gp_name, ln.ln_name, ln.ln_namelen)) {
+ rc = -EFAULT;
+ goto lb_free;
+ }
+
+ if (put_user('\0', arg->gp_name + ln.ln_namelen)) {
+ rc = -EFAULT;
+ goto lb_free;
+ }
+
+lb_free:
+ lu_buf_free(&buf);
+ldata_free:
+ kfree(ldata);
+ return rc;
+}
diff --git a/drivers/staging/lustre/lustre/llite/xattr.c b/drivers/staging/lustre/lustre/llite/xattr.c
index 17ad04f..0e6a559 100644
--- a/drivers/staging/lustre/lustre/llite/xattr.c
+++ b/drivers/staging/lustre/lustre/llite/xattr.c
@@ -44,14 +44,6 @@

#include "llite_internal.h"

-#define XATTR_USER_T (1)
-#define XATTR_TRUSTED_T (2)
-#define XATTR_SECURITY_T (3)
-#define XATTR_ACL_ACCESS_T (4)
-#define XATTR_ACL_DEFAULT_T (5)
-#define XATTR_LUSTRE_T (6)
-#define XATTR_OTHER_T (7)
-
static
int get_xattr_type(const char *name)
{
@@ -219,7 +211,7 @@ static int ll_xattr_set(const struct xattr_handler *handler,
flags);
}

-static int
+int
ll_xattr_list(struct inode *inode, const char *name, int type, void *buffer,
size_t size, __u64 valid)
{
--
1.7.1