linux-stable/fs/xfs/libxfs/xfs_dir2.h
Darrick J. Wong 6da1b4b1ab xfs: fix an ABBA deadlock in xfs_rename
When overlayfs is running on top of xfs and the user unlinks a file in
the overlay, overlayfs will create a whiteout inode and ask xfs to
"rename" the whiteout file atop the one being unlinked.  If the file
being unlinked loses its one nlink, we then have to put the inode on the
unlinked list.

This requires us to grab the AGI buffer of the whiteout inode to take it
off the unlinked list (which is where whiteouts are created) and to grab
the AGI buffer of the file being deleted.  If the whiteout was created
in a higher numbered AG than the file being deleted, we'll lock the AGIs
in the wrong order and deadlock.

Therefore, grab all the AGI locks we think we'll need ahead of time, and
in order of increasing AG number per the locking rules.

Reported-by: wenli xie <wlxie7296@gmail.com>
Fixes: 93597ae8da ("xfs: Fix deadlock between AGI and AGF when target_ip exists in xfs_rename()")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2021-01-22 16:54:43 -08:00

251 lines
7.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#ifndef __XFS_DIR2_H__
#define __XFS_DIR2_H__
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
struct xfs_da_args;
struct xfs_inode;
struct xfs_mount;
struct xfs_trans;
struct xfs_dir2_sf_hdr;
struct xfs_dir2_sf_entry;
struct xfs_dir2_data_hdr;
struct xfs_dir2_data_entry;
struct xfs_dir2_data_unused;
struct xfs_dir3_icfree_hdr;
struct xfs_dir3_icleaf_hdr;
extern struct xfs_name xfs_name_dotdot;
/*
* Convert inode mode to directory entry filetype
*/
extern unsigned char xfs_mode_to_ftype(int mode);
/*
* Generic directory interface routines
*/
extern void xfs_dir_startup(void);
extern int xfs_da_mount(struct xfs_mount *mp);
extern void xfs_da_unmount(struct xfs_mount *mp);
extern int xfs_dir_isempty(struct xfs_inode *dp);
extern int xfs_dir_init(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_inode *pdp);
extern int xfs_dir_createname(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_name *name, xfs_ino_t inum,
xfs_extlen_t tot);
extern int xfs_dir_lookup(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_name *name, xfs_ino_t *inum,
struct xfs_name *ci_name);
extern int xfs_dir_removename(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_name *name, xfs_ino_t ino,
xfs_extlen_t tot);
extern int xfs_dir_replace(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_name *name, xfs_ino_t inum,
xfs_extlen_t tot);
extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_name *name);
/*
* Direct call from the bmap code, bypassing the generic directory layer.
*/
extern int xfs_dir2_sf_to_block(struct xfs_da_args *args);
/*
* Interface routines used by userspace utilities
*/
extern int xfs_dir2_isblock(struct xfs_da_args *args, int *r);
extern int xfs_dir2_isleaf(struct xfs_da_args *args, int *r);
extern int xfs_dir2_shrink_inode(struct xfs_da_args *args, xfs_dir2_db_t db,
struct xfs_buf *bp);
extern void xfs_dir2_data_freescan(struct xfs_mount *mp,
struct xfs_dir2_data_hdr *hdr, int *loghead);
extern void xfs_dir2_data_log_entry(struct xfs_da_args *args,
struct xfs_buf *bp, struct xfs_dir2_data_entry *dep);
extern void xfs_dir2_data_log_header(struct xfs_da_args *args,
struct xfs_buf *bp);
extern void xfs_dir2_data_log_unused(struct xfs_da_args *args,
struct xfs_buf *bp, struct xfs_dir2_data_unused *dup);
extern void xfs_dir2_data_make_free(struct xfs_da_args *args,
struct xfs_buf *bp, xfs_dir2_data_aoff_t offset,
xfs_dir2_data_aoff_t len, int *needlogp, int *needscanp);
extern int xfs_dir2_data_use_free(struct xfs_da_args *args,
struct xfs_buf *bp, struct xfs_dir2_data_unused *dup,
xfs_dir2_data_aoff_t offset, xfs_dir2_data_aoff_t len,
int *needlogp, int *needscanp);
extern struct xfs_dir2_data_free *xfs_dir2_data_freefind(
struct xfs_dir2_data_hdr *hdr, struct xfs_dir2_data_free *bf,
struct xfs_dir2_data_unused *dup);
extern int xfs_dir_ino_validate(struct xfs_mount *mp, xfs_ino_t ino);
extern const struct xfs_buf_ops xfs_dir3_block_buf_ops;
extern const struct xfs_buf_ops xfs_dir3_leafn_buf_ops;
extern const struct xfs_buf_ops xfs_dir3_leaf1_buf_ops;
extern const struct xfs_buf_ops xfs_dir3_free_buf_ops;
extern const struct xfs_buf_ops xfs_dir3_data_buf_ops;
/*
* Directory offset/block conversion functions.
*
* DB blocks here are logical directory block numbers, not filesystem blocks.
*/
/*
* Convert dataptr to byte in file space
*/
static inline xfs_dir2_off_t
xfs_dir2_dataptr_to_byte(xfs_dir2_dataptr_t dp)
{
return (xfs_dir2_off_t)dp << XFS_DIR2_DATA_ALIGN_LOG;
}
/*
* Convert byte in file space to dataptr. It had better be aligned.
*/
static inline xfs_dir2_dataptr_t
xfs_dir2_byte_to_dataptr(xfs_dir2_off_t by)
{
return (xfs_dir2_dataptr_t)(by >> XFS_DIR2_DATA_ALIGN_LOG);
}
/*
* Convert byte in space to (DB) block
*/
static inline xfs_dir2_db_t
xfs_dir2_byte_to_db(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
{
return (xfs_dir2_db_t)(by >> geo->blklog);
}
/*
* Convert dataptr to a block number
*/
static inline xfs_dir2_db_t
xfs_dir2_dataptr_to_db(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
{
return xfs_dir2_byte_to_db(geo, xfs_dir2_dataptr_to_byte(dp));
}
/*
* Convert byte in space to offset in a block
*/
static inline xfs_dir2_data_aoff_t
xfs_dir2_byte_to_off(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
{
return (xfs_dir2_data_aoff_t)(by & (geo->blksize - 1));
}
/*
* Convert dataptr to a byte offset in a block
*/
static inline xfs_dir2_data_aoff_t
xfs_dir2_dataptr_to_off(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
{
return xfs_dir2_byte_to_off(geo, xfs_dir2_dataptr_to_byte(dp));
}
/*
* Convert block and offset to byte in space
*/
static inline xfs_dir2_off_t
xfs_dir2_db_off_to_byte(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
xfs_dir2_data_aoff_t o)
{
return ((xfs_dir2_off_t)db << geo->blklog) + o;
}
/*
* Convert block (DB) to block (dablk)
*/
static inline xfs_dablk_t
xfs_dir2_db_to_da(struct xfs_da_geometry *geo, xfs_dir2_db_t db)
{
return (xfs_dablk_t)(db << (geo->blklog - geo->fsblog));
}
/*
* Convert byte in space to (DA) block
*/
static inline xfs_dablk_t
xfs_dir2_byte_to_da(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
{
return xfs_dir2_db_to_da(geo, xfs_dir2_byte_to_db(geo, by));
}
/*
* Convert block and offset to dataptr
*/
static inline xfs_dir2_dataptr_t
xfs_dir2_db_off_to_dataptr(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
xfs_dir2_data_aoff_t o)
{
return xfs_dir2_byte_to_dataptr(xfs_dir2_db_off_to_byte(geo, db, o));
}
/*
* Convert block (dablk) to block (DB)
*/
static inline xfs_dir2_db_t
xfs_dir2_da_to_db(struct xfs_da_geometry *geo, xfs_dablk_t da)
{
return (xfs_dir2_db_t)(da >> (geo->blklog - geo->fsblog));
}
/*
* Convert block (dablk) to byte offset in space
*/
static inline xfs_dir2_off_t
xfs_dir2_da_to_byte(struct xfs_da_geometry *geo, xfs_dablk_t da)
{
return xfs_dir2_db_off_to_byte(geo, xfs_dir2_da_to_db(geo, da), 0);
}
/*
* Directory tail pointer accessor functions. Based on block geometry.
*/
static inline struct xfs_dir2_block_tail *
xfs_dir2_block_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_data_hdr *hdr)
{
return ((struct xfs_dir2_block_tail *)
((char *)hdr + geo->blksize)) - 1;
}
static inline struct xfs_dir2_leaf_tail *
xfs_dir2_leaf_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_leaf *lp)
{
return (struct xfs_dir2_leaf_tail *)
((char *)lp + geo->blksize -
sizeof(struct xfs_dir2_leaf_tail));
}
/*
* The Linux API doesn't pass down the total size of the buffer
* we read into down to the filesystem. With the filldir concept
* it's not needed for correct information, but the XFS dir2 leaf
* code wants an estimate of the buffer size to calculate it's
* readahead window and size the buffers used for mapping to
* physical blocks.
*
* Try to give it an estimate that's good enough, maybe at some
* point we can change the ->readdir prototype to include the
* buffer size. For now we use the current glibc buffer size.
* musl libc hardcodes 2k and dietlibc uses PAGE_SIZE.
*/
#define XFS_READDIR_BUFSIZE (32768)
unsigned char xfs_dir3_get_dtype(struct xfs_mount *mp, uint8_t filetype);
unsigned int xfs_dir3_data_end_offset(struct xfs_da_geometry *geo,
struct xfs_dir2_data_hdr *hdr);
bool xfs_dir2_namecheck(const void *name, size_t length);
#endif /* __XFS_DIR2_H__ */