From: Darrick J. Wong <djwong@xxxxxxxxxx> This patch adds a pair of new file ioctls to retrieve the parent pointer of a given inode. They both return the same results, but one operates on the file descriptor passed to ioctl() whereas the other allows the caller to specify a file handle for which the caller wants results. Signed-off-by: Allison Henderson <allison.henderson@xxxxxxxxxx> Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx> [djwong: adjust to new ondisk format, split ioctls] Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> --- fs/xfs/libxfs/xfs_fs.h | 73 ++++++++++++ fs/xfs/libxfs/xfs_ondisk.h | 5 + fs/xfs/libxfs/xfs_parent.c | 35 ++++++ fs/xfs/libxfs/xfs_parent.h | 5 + fs/xfs/xfs_handle.c | 259 ++++++++++++++++++++++++++++++++++++++++++++ fs/xfs/xfs_handle.h | 5 + fs/xfs/xfs_ioctl.c | 6 + fs/xfs/xfs_trace.c | 1 fs/xfs/xfs_trace.h | 92 ++++++++++++++++ 9 files changed, 480 insertions(+), 1 deletion(-) diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h index 51aa4774f57a2..fa28c18e521bf 100644 --- a/fs/xfs/libxfs/xfs_fs.h +++ b/fs/xfs/libxfs/xfs_fs.h @@ -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 */ +} __packed; + +/* 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 __pad; + + /* 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) +{ + char *next = ((char *)gpr + gpr->gpr_reclen); + char *end = (char *)(uintptr_t)(gp->gp_buffer + gp->gp_bufsize); + + if (next >= end) + return NULL; + + return (struct xfs_getparents_rec *)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 diff --git a/fs/xfs/libxfs/xfs_ondisk.h b/fs/xfs/libxfs/xfs_ondisk.h index 25952ef584eee..34c972113d997 100644 --- a/fs/xfs/libxfs/xfs_ondisk.h +++ b/fs/xfs/libxfs/xfs_ondisk.h @@ -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, 26); + 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 diff --git a/fs/xfs/libxfs/xfs_parent.c b/fs/xfs/libxfs/xfs_parent.c index 86c808157294e..db8cfad0b968e 100644 --- a/fs/xfs/libxfs/xfs_parent.c +++ b/fs/xfs/libxfs/xfs_parent.c @@ -259,3 +259,38 @@ xfs_parent_replacename( xfs_attr_defer_parent(&ppargs->args, XFS_ATTR_DEFER_REPLACE); return 0; } + +/* + * Extract parent pointer information from any xattr into @parent_ino/gen. + * The last two parameters can be NULL pointers. + * + * Returns 1 if this is a valid parent pointer; 0 if this is not a parent + * pointer xattr at all; or -EFSCORRUPTED for garbage. + */ +int +xfs_parent_from_xattr( + 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; + + if (!(attr_flags & XFS_ATTR_PARENT)) + return 0; + + 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 1; +} diff --git a/fs/xfs/libxfs/xfs_parent.h b/fs/xfs/libxfs/xfs_parent.h index 768633b313671..3003ab496f854 100644 --- a/fs/xfs/libxfs/xfs_parent.h +++ b/fs/xfs/libxfs/xfs_parent.h @@ -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_xattr(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__ */ diff --git a/fs/xfs/xfs_handle.c b/fs/xfs/xfs_handle.c index abeca486a2c91..833b0d7d8bea1 100644 --- a/fs/xfs/xfs_handle.c +++ b/fs/xfs/xfs_handle.c @@ -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" @@ -645,3 +646,261 @@ 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(uint32_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 ret; + + ret = xfs_parent_from_xattr(mp, flags, name, namelen, value, valuelen, + &ino, &gen); + if (ret < 0) { + xfs_inode_mark_sick(ip, XFS_SICK_INO_PARENT); + context->seen_enough = -EFSCORRUPTED; + return; + } + if (ret != 1) + 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->__pad) + return -EINVAL; + + bufsize = round_down(gp->gp_bufsize, sizeof(uint32_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 dentry *dentry; + 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; + + dentry = xfs_khandle_to_dentry(file, &kreq->gph_handle); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + gpx.ip = XFS_I(dentry->d_inode); + error = xfs_getparents(&gpx); + dput(dentry); + if (error) + return error; + + if (copy_to_user(ureq, kreq, sizeof(*kreq))) + return -EFAULT; + + return 0; +} diff --git a/fs/xfs/xfs_handle.h b/fs/xfs/xfs_handle.h index e39eaf4689da9..6799a86d8565c 100644 --- a/fs/xfs/xfs_handle.h +++ b/fs/xfs/xfs_handle.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. */ #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__ */ diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index 7b347cdd28785..c7a15b5f33aa4 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -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" @@ -1542,7 +1543,10 @@ 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: diff --git a/fs/xfs/xfs_trace.c b/fs/xfs/xfs_trace.c index cf92a3bd56c79..9c7fbaae2717d 100644 --- a/fs/xfs/xfs_trace.c +++ b/fs/xfs/xfs_trace.c @@ -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 diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index e6cbdffb14f64..4438b62a8c562 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -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" }, \ @@ -5158,6 +5161,95 @@ 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