@@ -840,6 +840,77 @@ struct xfs_commit_range {
XFS_EXCHANGE_RANGE_DRY_RUN | \
XFS_EXCHANGE_RANGE_FILE1_WRITTEN)
+/* Iterating parent pointers of files. */
+
+/* target was the root directory */
+#define XFS_GETPARENTS_OFLAG_ROOT (1U << 0)
+
+/* Cursor is done iterating pptrs */
+#define XFS_GETPARENTS_OFLAG_DONE (1U << 1)
+
+#define XFS_GETPARENTS_OFLAGS_ALL (XFS_GETPARENTS_OFLAG_ROOT | \
+ XFS_GETPARENTS_OFLAG_DONE)
+
+#define XFS_GETPARENTS_IFLAGS_ALL (0)
+
+struct xfs_getparents_rec {
+ struct xfs_handle gpr_parent; /* Handle to parent */
+ __u16 gpr_reclen; /* Length of entire record */
+ char gpr_name[]; /* Null-terminated filename */
+};
+
+/* Iterate through this file's directory parent pointers */
+struct xfs_getparents {
+ /*
+ * Structure to track progress in iterating the parent pointers.
+ * Must be initialized to zeroes before the first ioctl call, and
+ * not touched by callers after that.
+ */
+ struct xfs_attrlist_cursor gp_cursor;
+
+ /* Input flags: XFS_GETPARENTS_IFLAG* */
+ __u16 gp_iflags;
+
+ /* Output flags: XFS_GETPARENTS_OFLAG* */
+ __u16 gp_oflags;
+
+ /* Size of the gp_buffer in bytes */
+ __u32 gp_bufsize;
+
+ /* Must be set to zero */
+ __u64 gp_reserved;
+
+ /* Pointer to a buffer in which to place xfs_getparents_rec */
+ __u64 gp_buffer;
+};
+
+static inline struct xfs_getparents_rec *
+xfs_getparents_first_rec(struct xfs_getparents *gp)
+{
+ return (struct xfs_getparents_rec *)(uintptr_t)gp->gp_buffer;
+}
+
+static inline struct xfs_getparents_rec *
+xfs_getparents_next_rec(struct xfs_getparents *gp,
+ struct xfs_getparents_rec *gpr)
+{
+ void *next = ((void *)gpr + gpr->gpr_reclen);
+ void *end = (void *)(uintptr_t)(gp->gp_buffer + gp->gp_bufsize);
+
+ if (next >= end)
+ return NULL;
+
+ return next;
+}
+
+/* Iterate through this file handle's directory parent pointers. */
+struct xfs_getparents_by_handle {
+ /* Handle to file whose parents we want. */
+ struct xfs_handle gph_handle;
+
+ struct xfs_getparents gph_request;
+};
+
/*
* ioctl commands that are used by Linux filesystems
*/
@@ -875,6 +946,8 @@ struct xfs_commit_range {
/* XFS_IOC_GETFSMAP ------ hoisted 59 */
#define XFS_IOC_SCRUB_METADATA _IOWR('X', 60, struct xfs_scrub_metadata)
#define XFS_IOC_AG_GEOMETRY _IOWR('X', 61, struct xfs_ag_geometry)
+#define XFS_IOC_GETPARENTS _IOWR('X', 62, struct xfs_getparents)
+#define XFS_IOC_GETPARENTS_BY_HANDLE _IOWR('X', 63, struct xfs_getparents_by_handle)
/*
* ioctl commands that replace IRIX syssgi()'s
@@ -156,6 +156,11 @@ xfs_check_ondisk_structs(void)
XFS_CHECK_OFFSET(struct xfs_efi_log_format_32, efi_extents, 16);
XFS_CHECK_OFFSET(struct xfs_efi_log_format_64, efi_extents, 16);
+ /* parent pointer ioctls */
+ XFS_CHECK_STRUCT_SIZE(struct xfs_getparents_rec, 32);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_getparents, 40);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_getparents_by_handle, 64);
+
/*
* The v5 superblock format extended several v4 header structures with
* additional data. While new fields are only accessible on v5
@@ -257,3 +257,37 @@ xfs_parent_replacename(
xfs_attr_defer_parent(&ppargs->args, XFS_ATTR_DEFER_REPLACE);
return 0;
}
+
+/*
+ * Extract parent pointer information from any parent pointer xattr into
+ * @parent_ino/gen. The last two parameters can be NULL pointers.
+ *
+ * Returns 0 if this is not a parent pointer xattr at all; or -EFSCORRUPTED for
+ * garbage.
+ */
+int
+xfs_parent_from_attr(
+ struct xfs_mount *mp,
+ unsigned int attr_flags,
+ const unsigned char *name,
+ unsigned int namelen,
+ const void *value,
+ unsigned int valuelen,
+ xfs_ino_t *parent_ino,
+ uint32_t *parent_gen)
+{
+ const struct xfs_parent_rec *rec = value;
+
+ ASSERT(attr_flags & XFS_ATTR_PARENT);
+
+ if (!xfs_parent_namecheck(attr_flags, name, namelen))
+ return -EFSCORRUPTED;
+ if (!xfs_parent_valuecheck(mp, value, valuelen))
+ return -EFSCORRUPTED;
+
+ if (parent_ino)
+ *parent_ino = be64_to_cpu(rec->p_ino);
+ if (parent_gen)
+ *parent_gen = be32_to_cpu(rec->p_gen);
+ return 0;
+}
@@ -91,4 +91,9 @@ int xfs_parent_replacename(struct xfs_trans *tp,
struct xfs_inode *new_dp, const struct xfs_name *new_name,
struct xfs_inode *child);
+int xfs_parent_from_attr(struct xfs_mount *mp, unsigned int attr_flags,
+ const unsigned char *name, unsigned int namelen,
+ const void *value, unsigned int valuelen,
+ xfs_ino_t *parent_ino, uint32_t *parent_gen);
+
#endif /* __XFS_PARENT_H__ */
@@ -102,7 +102,7 @@ xfs_fs_encode_fh(
return fileid_type;
}
-STATIC struct inode *
+struct inode *
xfs_nfs_get_inode(
struct super_block *sb,
u64 ino,
@@ -57,4 +57,6 @@ struct xfs_fid64 {
/* This flag goes on the wire. Don't play with it. */
#define XFS_FILEID_TYPE_64FLAG 0x80 /* NFS fileid has 64bit inodes */
+struct inode *xfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 gen);
+
#endif /* __XFS_EXPORT_H__ */
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * Copyright (c) 2022-2024 Oracle.
* All rights reserved.
*/
#include "xfs.h"
@@ -656,3 +657,288 @@ xfs_attrmulti_by_handle(
dput(dentry);
return error;
}
+
+struct xfs_getparents_ctx {
+ struct xfs_attr_list_context context;
+ struct xfs_getparents_by_handle gph;
+
+ /* File to target */
+ struct xfs_inode *ip;
+
+ /* Internal buffer where we format records */
+ void *krecords;
+
+ /* Last record filled out */
+ struct xfs_getparents_rec *lastrec;
+
+ unsigned int count;
+};
+
+static inline unsigned int
+xfs_getparents_rec_sizeof(
+ unsigned int namelen)
+{
+ return round_up(sizeof(struct xfs_getparents_rec) + namelen + 1,
+ sizeof(uint64_t));
+}
+
+static void
+xfs_getparents_put_listent(
+ struct xfs_attr_list_context *context,
+ int flags,
+ unsigned char *name,
+ int namelen,
+ void *value,
+ int valuelen)
+{
+ struct xfs_getparents_ctx *gpx =
+ container_of(context, struct xfs_getparents_ctx, context);
+ struct xfs_inode *ip = context->dp;
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_getparents *gp = &gpx->gph.gph_request;
+ struct xfs_getparents_rec *gpr = gpx->krecords + context->firstu;
+ unsigned short reclen =
+ xfs_getparents_rec_sizeof(namelen);
+ xfs_ino_t ino;
+ uint32_t gen;
+ int error;
+
+ if (!(flags & XFS_ATTR_PARENT))
+ return;
+
+ error = xfs_parent_from_attr(mp, flags, name, namelen, value, valuelen,
+ &ino, &gen);
+ if (error) {
+ xfs_inode_mark_sick(ip, XFS_SICK_INO_PARENT);
+ context->seen_enough = -EFSCORRUPTED;
+ return;
+ }
+
+ /*
+ * We found a parent pointer, but we've filled up the buffer. Signal
+ * to the caller that we did /not/ reach the end of the parent pointer
+ * recordset.
+ */
+ if (context->firstu > context->bufsize - reclen) {
+ context->seen_enough = 1;
+ return;
+ }
+
+ /* Format the parent pointer directly into the caller buffer. */
+ gpr->gpr_reclen = reclen;
+ xfs_filehandle_init(mp, ino, gen, &gpr->gpr_parent);
+ memcpy(gpr->gpr_name, name, namelen);
+ gpr->gpr_name[namelen] = 0;
+
+ trace_xfs_getparents_put_listent(ip, gp, context, gpr);
+
+ context->firstu += reclen;
+ gpx->count++;
+ gpx->lastrec = gpr;
+}
+
+/* Expand the last record to fill the rest of the caller's buffer. */
+static inline void
+xfs_getparents_expand_lastrec(
+ struct xfs_getparents_ctx *gpx)
+{
+ struct xfs_getparents *gp = &gpx->gph.gph_request;
+ struct xfs_getparents_rec *gpr = gpx->lastrec;
+
+ if (!gpx->lastrec)
+ gpr = gpx->krecords;
+
+ gpr->gpr_reclen = gp->gp_bufsize - ((void *)gpr - gpx->krecords);
+
+ trace_xfs_getparents_expand_lastrec(gpx->ip, gp, &gpx->context, gpr);
+}
+
+static inline void __user *u64_to_uptr(u64 val)
+{
+ return (void __user *)(uintptr_t)val;
+}
+
+/* Retrieve the parent pointers for a given inode. */
+STATIC int
+xfs_getparents(
+ struct xfs_getparents_ctx *gpx)
+{
+ struct xfs_getparents *gp = &gpx->gph.gph_request;
+ struct xfs_inode *ip = gpx->ip;
+ struct xfs_mount *mp = ip->i_mount;
+ size_t bufsize;
+ int error;
+
+ /* Check size of buffer requested by user */
+ if (gp->gp_bufsize > XFS_XATTR_LIST_MAX)
+ return -ENOMEM;
+ if (gp->gp_bufsize < xfs_getparents_rec_sizeof(1))
+ return -EINVAL;
+
+ if (gp->gp_iflags & ~XFS_GETPARENTS_IFLAGS_ALL)
+ return -EINVAL;
+ if (gp->gp_reserved)
+ return -EINVAL;
+
+ bufsize = round_down(gp->gp_bufsize, sizeof(uint64_t));
+ gpx->krecords = kvzalloc(bufsize, GFP_KERNEL);
+ if (!gpx->krecords) {
+ bufsize = min(bufsize, PAGE_SIZE);
+ gpx->krecords = kvzalloc(bufsize, GFP_KERNEL);
+ if (!gpx->krecords)
+ return -ENOMEM;
+ }
+
+ gpx->context.dp = ip;
+ gpx->context.resynch = 1;
+ gpx->context.put_listent = xfs_getparents_put_listent;
+ gpx->context.bufsize = bufsize;
+ /* firstu is used to track the bytes filled in the buffer */
+ gpx->context.firstu = 0;
+
+ /* Copy the cursor provided by caller */
+ memcpy(&gpx->context.cursor, &gp->gp_cursor,
+ sizeof(struct xfs_attrlist_cursor));
+ gpx->count = 0;
+ gp->gp_oflags = 0;
+
+ trace_xfs_getparents_begin(ip, gp, &gpx->context.cursor);
+
+ error = xfs_attr_list(&gpx->context);
+ if (error)
+ goto out_free_buf;
+ if (gpx->context.seen_enough < 0) {
+ error = gpx->context.seen_enough;
+ goto out_free_buf;
+ }
+ xfs_getparents_expand_lastrec(gpx);
+
+ /* Update the caller with the current cursor position */
+ memcpy(&gp->gp_cursor, &gpx->context.cursor,
+ sizeof(struct xfs_attrlist_cursor));
+
+ /* Is this the root directory? */
+ if (ip->i_ino == mp->m_sb.sb_rootino)
+ gp->gp_oflags |= XFS_GETPARENTS_OFLAG_ROOT;
+
+ if (gpx->context.seen_enough == 0) {
+ /*
+ * If we did not run out of buffer space, then we reached the
+ * end of the pptr recordset, so set the DONE flag.
+ */
+ gp->gp_oflags |= XFS_GETPARENTS_OFLAG_DONE;
+ } else if (gpx->count == 0) {
+ /*
+ * If we ran out of buffer space before copying any parent
+ * pointers at all, the caller's buffer was too short. Tell
+ * userspace that, erm, the message is too long.
+ */
+ error = -EMSGSIZE;
+ goto out_free_buf;
+ }
+
+ trace_xfs_getparents_end(ip, gp, &gpx->context.cursor);
+
+ ASSERT(gpx->context.firstu <= gpx->gph.gph_request.gp_bufsize);
+
+ /* Copy the records to userspace. */
+ if (copy_to_user(u64_to_uptr(gpx->gph.gph_request.gp_buffer),
+ gpx->krecords, gpx->context.firstu))
+ error = -EFAULT;
+
+out_free_buf:
+ kvfree(gpx->krecords);
+ gpx->krecords = NULL;
+ return error;
+}
+
+/* Retrieve the parents of this file and pass them back to userspace. */
+int
+xfs_ioc_getparents(
+ struct file *file,
+ struct xfs_getparents __user *ureq)
+{
+ struct xfs_getparents_ctx gpx = {
+ .ip = XFS_I(file_inode(file)),
+ };
+ struct xfs_getparents *kreq = &gpx.gph.gph_request;
+ struct xfs_mount *mp = gpx.ip->i_mount;
+ int error;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (!xfs_has_parent(mp))
+ return -EOPNOTSUPP;
+ if (copy_from_user(kreq, ureq, sizeof(*kreq)))
+ return -EFAULT;
+
+ error = xfs_getparents(&gpx);
+ if (error)
+ return error;
+
+ if (copy_to_user(ureq, kreq, sizeof(*kreq)))
+ return -EFAULT;
+
+ return 0;
+}
+
+/* Retrieve the parents of this file handle and pass them back to userspace. */
+int
+xfs_ioc_getparents_by_handle(
+ struct file *file,
+ struct xfs_getparents_by_handle __user *ureq)
+{
+ struct xfs_getparents_ctx gpx = { };
+ struct xfs_inode *ip = XFS_I(file_inode(file));
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_getparents_by_handle *kreq = &gpx.gph;
+ struct xfs_handle *handle = &kreq->gph_handle;
+ struct inode *inode;
+ int error;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (!xfs_has_parent(mp))
+ return -EOPNOTSUPP;
+ if (copy_from_user(kreq, ureq, sizeof(*kreq)))
+ return -EFAULT;
+
+ /*
+ * We don't use exportfs_decode_fh because it does too much work here.
+ * If the handle refers to a directory, the exportfs code will walk
+ * upwards through the directory tree to connect the dentries to the
+ * root directory dentry. For GETPARENTS we don't care about that
+ * because we're not actually going to open a file descriptor; we only
+ * want to open an inode and read its parent pointers.
+ *
+ * Note that xfs_scrub uses GETPARENTS to log that it will try to fix a
+ * corrupted file's metadata. For this usecase we would really rather
+ * userspace single-step the path reconstruction to avoid loops or
+ * other strange things if the directory tree is corrupt.
+ */
+ if (!S_ISDIR(VFS_I(ip)->i_mode))
+ return -ENOTDIR;
+
+ if (memcmp(&handle->ha_fsid, mp->m_fixedfsid, sizeof(struct xfs_fsid)))
+ return -ESTALE;
+
+ if (handle->ha_fid.fid_len != xfs_filehandle_fid_len())
+ return -EINVAL;
+
+ inode = xfs_nfs_get_inode(mp->m_super, handle->ha_fid.fid_ino,
+ handle->ha_fid.fid_gen);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ gpx.ip = XFS_I(inode);
+ error = xfs_getparents(&gpx);
+ if (error)
+ goto out_rele;
+
+ if (copy_to_user(ureq, kreq, sizeof(*kreq)))
+ error = -EFAULT;
+
+out_rele:
+ xfs_irele(gpx.ip);
+ return error;
+}
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * Copyright (c) 2022-2024 Oracle.
* All rights reserved.
*/
#ifndef __XFS_HANDLE_H__
@@ -25,4 +26,8 @@ int xfs_ioc_attr_list(struct xfs_inode *dp, void __user *ubuf,
struct dentry *xfs_handle_to_dentry(struct file *parfilp, void __user *uhandle,
u32 hlen);
+int xfs_ioc_getparents(struct file *file, struct xfs_getparents __user *arg);
+int xfs_ioc_getparents_by_handle(struct file *file,
+ struct xfs_getparents_by_handle __user *arg);
+
#endif /* __XFS_HANDLE_H__ */
@@ -35,6 +35,7 @@
#include "xfs_health.h"
#include "xfs_reflink.h"
#include "xfs_ioctl.h"
+#include "xfs_xattr.h"
#include "xfs_rtbitmap.h"
#include "xfs_file.h"
#include "xfs_exchrange.h"
@@ -1424,7 +1425,10 @@ xfs_file_ioctl(
case XFS_IOC_FSGETXATTRA:
return xfs_ioc_fsgetxattra(ip, arg);
-
+ case XFS_IOC_GETPARENTS:
+ return xfs_ioc_getparents(filp, arg);
+ case XFS_IOC_GETPARENTS_BY_HANDLE:
+ return xfs_ioc_getparents_by_handle(filp, arg);
case XFS_IOC_GETBMAP:
case XFS_IOC_GETBMAPA:
case XFS_IOC_GETBMAPX:
@@ -41,6 +41,7 @@
#include "xfs_bmap.h"
#include "xfs_exchmaps.h"
#include "xfs_exchrange.h"
+#include "xfs_parent.h"
/*
* We include this last to have the helpers above available for the trace
@@ -87,6 +87,9 @@ struct xfs_bmap_intent;
struct xfs_exchmaps_intent;
struct xfs_exchmaps_req;
struct xfs_exchrange;
+struct xfs_getparents;
+struct xfs_parent_irec;
+struct xfs_attrlist_cursor_kern;
#define XFS_ATTR_FILTER_FLAGS \
{ XFS_ATTR_ROOT, "ROOT" }, \
@@ -5153,6 +5156,95 @@ TRACE_EVENT(xfs_exchmaps_delta_nextents,
__entry->d_nexts1, __entry->d_nexts2)
);
+DECLARE_EVENT_CLASS(xfs_getparents_rec_class,
+ TP_PROTO(struct xfs_inode *ip, const struct xfs_getparents *ppi,
+ const struct xfs_attr_list_context *context,
+ const struct xfs_getparents_rec *pptr),
+ TP_ARGS(ip, ppi, context, pptr),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_ino_t, ino)
+ __field(unsigned int, firstu)
+ __field(unsigned short, reclen)
+ __field(unsigned int, bufsize)
+ __field(xfs_ino_t, parent_ino)
+ __field(unsigned int, parent_gen)
+ __string(name, pptr->gpr_name)
+ ),
+ TP_fast_assign(
+ __entry->dev = ip->i_mount->m_super->s_dev;
+ __entry->ino = ip->i_ino;
+ __entry->firstu = context->firstu;
+ __entry->reclen = pptr->gpr_reclen;
+ __entry->bufsize = ppi->gp_bufsize;
+ __entry->parent_ino = pptr->gpr_parent.ha_fid.fid_ino;
+ __entry->parent_gen = pptr->gpr_parent.ha_fid.fid_gen;
+ __assign_str(name, pptr->gpr_name);
+ ),
+ TP_printk("dev %d:%d ino 0x%llx firstu %u reclen %u bufsize %u parent_ino 0x%llx parent_gen 0x%x name '%s'",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->ino,
+ __entry->firstu,
+ __entry->reclen,
+ __entry->bufsize,
+ __entry->parent_ino,
+ __entry->parent_gen,
+ __get_str(name))
+)
+#define DEFINE_XFS_GETPARENTS_REC_EVENT(name) \
+DEFINE_EVENT(xfs_getparents_rec_class, name, \
+ TP_PROTO(struct xfs_inode *ip, const struct xfs_getparents *ppi, \
+ const struct xfs_attr_list_context *context, \
+ const struct xfs_getparents_rec *pptr), \
+ TP_ARGS(ip, ppi, context, pptr))
+DEFINE_XFS_GETPARENTS_REC_EVENT(xfs_getparents_put_listent);
+DEFINE_XFS_GETPARENTS_REC_EVENT(xfs_getparents_expand_lastrec);
+
+DECLARE_EVENT_CLASS(xfs_getparents_class,
+ TP_PROTO(struct xfs_inode *ip, const struct xfs_getparents *ppi,
+ const struct xfs_attrlist_cursor_kern *cur),
+ TP_ARGS(ip, ppi, cur),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_ino_t, ino)
+ __field(unsigned short, iflags)
+ __field(unsigned short, oflags)
+ __field(unsigned int, bufsize)
+ __field(unsigned int, hashval)
+ __field(unsigned int, blkno)
+ __field(unsigned int, offset)
+ __field(int, initted)
+ ),
+ TP_fast_assign(
+ __entry->dev = ip->i_mount->m_super->s_dev;
+ __entry->ino = ip->i_ino;
+ __entry->iflags = ppi->gp_iflags;
+ __entry->oflags = ppi->gp_oflags;
+ __entry->bufsize = ppi->gp_bufsize;
+ __entry->hashval = cur->hashval;
+ __entry->blkno = cur->blkno;
+ __entry->offset = cur->offset;
+ __entry->initted = cur->initted;
+ ),
+ TP_printk("dev %d:%d ino 0x%llx iflags 0x%x oflags 0x%x bufsize %u cur_init? %d hashval 0x%x blkno %u offset %u",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->ino,
+ __entry->iflags,
+ __entry->oflags,
+ __entry->bufsize,
+ __entry->initted,
+ __entry->hashval,
+ __entry->blkno,
+ __entry->offset)
+)
+#define DEFINE_XFS_GETPARENTS_EVENT(name) \
+DEFINE_EVENT(xfs_getparents_class, name, \
+ TP_PROTO(struct xfs_inode *ip, const struct xfs_getparents *ppi, \
+ const struct xfs_attrlist_cursor_kern *cur), \
+ TP_ARGS(ip, ppi, cur))
+DEFINE_XFS_GETPARENTS_EVENT(xfs_getparents_begin);
+DEFINE_XFS_GETPARENTS_EVENT(xfs_getparents_end);
+
#endif /* _TRACE_XFS_H */
#undef TRACE_INCLUDE_PATH