diff options
Diffstat (limited to 'fs/gfs2/export.c')
| -rw-r--r-- | fs/gfs2/export.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c new file mode 100644 index 000000000..cf4089523 --- /dev/null +++ b/fs/gfs2/export.c @@ -0,0 +1,196 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. + */ + +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <linux/exportfs.h> +#include <linux/gfs2_ondisk.h> +#include <linux/crc32.h> + +#include "gfs2.h" +#include "incore.h" +#include "dir.h" +#include "glock.h" +#include "glops.h" +#include "inode.h" +#include "super.h" +#include "rgrp.h" +#include "util.h" + +#define GFS2_SMALL_FH_SIZE 4 +#define GFS2_LARGE_FH_SIZE 8 +#define GFS2_OLD_FH_SIZE 10 + +static int gfs2_encode_fh(struct inode *inode, __u32 *p, int *len, + struct inode *parent) +{ + __be32 *fh = (__force __be32 *)p; + struct super_block *sb = inode->i_sb; + struct gfs2_inode *ip = GFS2_I(inode); + + if (parent && (*len < GFS2_LARGE_FH_SIZE)) { + *len = GFS2_LARGE_FH_SIZE; + return FILEID_INVALID; + } else if (*len < GFS2_SMALL_FH_SIZE) { + *len = GFS2_SMALL_FH_SIZE; + return FILEID_INVALID; + } + + fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32); + fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF); + fh[2] = cpu_to_be32(ip->i_no_addr >> 32); + fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF); + *len = GFS2_SMALL_FH_SIZE; + + if (!parent || inode == d_inode(sb->s_root)) + return *len; + + ip = GFS2_I(parent); + + fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32); + fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF); + fh[6] = cpu_to_be32(ip->i_no_addr >> 32); + fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF); + *len = GFS2_LARGE_FH_SIZE; + + return *len; +} + +struct get_name_filldir { + struct dir_context ctx; + struct gfs2_inum_host inum; + char *name; +}; + +static bool get_name_filldir(struct dir_context *ctx, const char *name, + int length, loff_t offset, u64 inum, + unsigned int type) +{ + struct get_name_filldir *gnfd = + container_of(ctx, struct get_name_filldir, ctx); + + if (inum != gnfd->inum.no_addr) + return true; + + memcpy(gnfd->name, name, length); + gnfd->name[length] = 0; + + return false; +} + +static int gfs2_get_name(struct dentry *parent, char *name, + struct dentry *child) +{ + struct inode *dir = d_inode(parent); + struct inode *inode = d_inode(child); + struct gfs2_inode *dip, *ip; + struct get_name_filldir gnfd = { + .ctx.actor = get_name_filldir, + .name = name + }; + struct gfs2_holder gh; + int error; + struct file_ra_state f_ra = { .start = 0 }; + + if (!dir) + return -EINVAL; + + if (!S_ISDIR(dir->i_mode) || !inode) + return -EINVAL; + + dip = GFS2_I(dir); + ip = GFS2_I(inode); + + *name = 0; + gnfd.inum.no_addr = ip->i_no_addr; + gnfd.inum.no_formal_ino = ip->i_no_formal_ino; + + error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh); + if (error) + return error; + + error = gfs2_dir_read(dir, &gnfd.ctx, &f_ra); + + gfs2_glock_dq_uninit(&gh); + + if (!error && !*name) + error = -ENOENT; + + return error; +} + +static struct dentry *gfs2_get_parent(struct dentry *child) +{ + return d_obtain_alias(gfs2_lookupi(d_inode(child), &gfs2_qdotdot, 1)); +} + +static struct dentry *gfs2_get_dentry(struct super_block *sb, + struct gfs2_inum_host *inum) +{ + struct gfs2_sbd *sdp = sb->s_fs_info; + struct inode *inode; + + if (!inum->no_formal_ino) + return ERR_PTR(-ESTALE); + inode = gfs2_lookup_by_inum(sdp, inum->no_addr, inum->no_formal_ino, + GFS2_BLKST_DINODE); + if (IS_ERR(inode)) + return ERR_CAST(inode); + return d_obtain_alias(inode); +} + +static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type) +{ + struct gfs2_inum_host this; + __be32 *fh = (__force __be32 *)fid->raw; + + switch (fh_type) { + case GFS2_SMALL_FH_SIZE: + case GFS2_LARGE_FH_SIZE: + case GFS2_OLD_FH_SIZE: + if (fh_len < GFS2_SMALL_FH_SIZE) + return NULL; + this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32; + this.no_formal_ino |= be32_to_cpu(fh[1]); + this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32; + this.no_addr |= be32_to_cpu(fh[3]); + return gfs2_get_dentry(sb, &this); + default: + return NULL; + } +} + +static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type) +{ + struct gfs2_inum_host parent; + __be32 *fh = (__force __be32 *)fid->raw; + + switch (fh_type) { + case GFS2_LARGE_FH_SIZE: + case GFS2_OLD_FH_SIZE: + if (fh_len < GFS2_LARGE_FH_SIZE) + return NULL; + parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32; + parent.no_formal_ino |= be32_to_cpu(fh[5]); + parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32; + parent.no_addr |= be32_to_cpu(fh[7]); + return gfs2_get_dentry(sb, &parent); + default: + return NULL; + } +} + +const struct export_operations gfs2_export_ops = { + .encode_fh = gfs2_encode_fh, + .fh_to_dentry = gfs2_fh_to_dentry, + .fh_to_parent = gfs2_fh_to_parent, + .get_name = gfs2_get_name, + .get_parent = gfs2_get_parent, +}; + |