diff options
Diffstat (limited to 'fs/gfs2/ops_export.c')
| -rw-r--r-- | fs/gfs2/ops_export.c | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/fs/gfs2/ops_export.c b/fs/gfs2/ops_export.c new file mode 100644 index 00000000000000..86127d93bd35f6 --- /dev/null +++ b/fs/gfs2/ops_export.c @@ -0,0 +1,298 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU General Public License version 2. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <linux/gfs2_ondisk.h> +#include <linux/crc32.h> +#include <linux/lm_interface.h> + +#include "gfs2.h" +#include "incore.h" +#include "dir.h" +#include "glock.h" +#include "glops.h" +#include "inode.h" +#include "ops_export.h" +#include "rgrp.h" +#include "util.h" + +static struct dentry *gfs2_decode_fh(struct super_block *sb, + __u32 *fh, + int fh_len, + int fh_type, + int (*acceptable)(void *context, + struct dentry *dentry), + void *context) +{ + struct gfs2_fh_obj fh_obj; + struct gfs2_inum *this, parent; + + if (fh_type != fh_len) + return NULL; + + this = &fh_obj.this; + fh_obj.imode = DT_UNKNOWN; + memset(&parent, 0, sizeof(struct gfs2_inum)); + + switch (fh_type) { + case GFS2_LARGE_FH_SIZE: + 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]); + fh_obj.imode = be32_to_cpu(fh[8]); + case GFS2_SMALL_FH_SIZE: + 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]); + break; + default: + return NULL; + } + + return gfs2_export_ops.find_exported_dentry(sb, &fh_obj, &parent, + acceptable, context); +} + +static int gfs2_encode_fh(struct dentry *dentry, __u32 *fh, int *len, + int connectable) +{ + struct inode *inode = dentry->d_inode; + struct super_block *sb = inode->i_sb; + struct gfs2_inode *ip = GFS2_I(inode); + + if (*len < GFS2_SMALL_FH_SIZE || + (connectable && *len < GFS2_LARGE_FH_SIZE)) + return 255; + + fh[0] = ip->i_num.no_formal_ino >> 32; + fh[0] = cpu_to_be32(fh[0]); + fh[1] = ip->i_num.no_formal_ino & 0xFFFFFFFF; + fh[1] = cpu_to_be32(fh[1]); + fh[2] = ip->i_num.no_addr >> 32; + fh[2] = cpu_to_be32(fh[2]); + fh[3] = ip->i_num.no_addr & 0xFFFFFFFF; + fh[3] = cpu_to_be32(fh[3]); + *len = GFS2_SMALL_FH_SIZE; + + if (!connectable || inode == sb->s_root->d_inode) + return *len; + + spin_lock(&dentry->d_lock); + inode = dentry->d_parent->d_inode; + ip = GFS2_I(inode); + igrab(inode); + spin_unlock(&dentry->d_lock); + + fh[4] = ip->i_num.no_formal_ino >> 32; + fh[4] = cpu_to_be32(fh[4]); + fh[5] = ip->i_num.no_formal_ino & 0xFFFFFFFF; + fh[5] = cpu_to_be32(fh[5]); + fh[6] = ip->i_num.no_addr >> 32; + fh[6] = cpu_to_be32(fh[6]); + fh[7] = ip->i_num.no_addr & 0xFFFFFFFF; + fh[7] = cpu_to_be32(fh[7]); + + fh[8] = cpu_to_be32(inode->i_mode); + fh[9] = 0; /* pad to double word */ + *len = GFS2_LARGE_FH_SIZE; + + iput(inode); + + return *len; +} + +struct get_name_filldir { + struct gfs2_inum inum; + char *name; +}; + +static int get_name_filldir(void *opaque, const char *name, unsigned int length, + u64 offset, struct gfs2_inum *inum, + unsigned int type) +{ + struct get_name_filldir *gnfd = (struct get_name_filldir *)opaque; + + if (!gfs2_inum_equal(inum, &gnfd->inum)) + return 0; + + memcpy(gnfd->name, name, length); + gnfd->name[length] = 0; + + return 1; +} + +static int gfs2_get_name(struct dentry *parent, char *name, + struct dentry *child) +{ + struct inode *dir = parent->d_inode; + struct inode *inode = child->d_inode; + struct gfs2_inode *dip, *ip; + struct get_name_filldir gnfd; + struct gfs2_holder gh; + u64 offset = 0; + int error; + + 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 = ip->i_num; + gnfd.name = name; + + error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh); + if (error) + return error; + + error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir); + + gfs2_glock_dq_uninit(&gh); + + if (!error && !*name) + error = -ENOENT; + + return error; +} + +static struct dentry *gfs2_get_parent(struct dentry *child) +{ + struct qstr dotdot; + struct inode *inode; + struct dentry *dentry; + + gfs2_str2qstr(&dotdot, ".."); + inode = gfs2_lookupi(child->d_inode, &dotdot, 1, NULL); + + if (!inode) + return ERR_PTR(-ENOENT); + /* + * In case of an error, @inode carries the error value, and we + * have to return that as a(n invalid) pointer to dentry. + */ + if (IS_ERR(inode)) + return ERR_PTR(PTR_ERR(inode)); + + dentry = d_alloc_anon(inode); + if (!dentry) { + iput(inode); + return ERR_PTR(-ENOMEM); + } + + return dentry; +} + +static struct dentry *gfs2_get_dentry(struct super_block *sb, void *inum_obj) +{ + struct gfs2_sbd *sdp = sb->s_fs_info; + struct gfs2_fh_obj *fh_obj = (struct gfs2_fh_obj *)inum_obj; + struct gfs2_inum *inum = &fh_obj->this; + struct gfs2_holder i_gh, ri_gh, rgd_gh; + struct gfs2_rgrpd *rgd; + struct inode *inode; + struct dentry *dentry; + int error; + + /* System files? */ + + inode = gfs2_ilookup(sb, inum); + if (inode) { + if (GFS2_I(inode)->i_num.no_formal_ino != inum->no_formal_ino) { + iput(inode); + return ERR_PTR(-ESTALE); + } + goto out_inode; + } + + error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops, + LM_ST_SHARED, LM_FLAG_ANY | GL_LOCAL_EXCL, + &i_gh); + if (error) + return ERR_PTR(error); + + error = gfs2_rindex_hold(sdp, &ri_gh); + if (error) + goto fail; + + error = -EINVAL; + rgd = gfs2_blk2rgrpd(sdp, inum->no_addr); + if (!rgd) + goto fail_rindex; + + error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh); + if (error) + goto fail_rindex; + + error = -ESTALE; + if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE) + goto fail_rgd; + + gfs2_glock_dq_uninit(&rgd_gh); + gfs2_glock_dq_uninit(&ri_gh); + + inode = gfs2_inode_lookup(sb, inum, fh_obj->imode); + if (!inode) + goto fail; + if (IS_ERR(inode)) { + error = PTR_ERR(inode); + goto fail; + } + + error = gfs2_inode_refresh(GFS2_I(inode)); + if (error) { + iput(inode); + goto fail; + } + + error = -EIO; + if (GFS2_I(inode)->i_di.di_flags & GFS2_DIF_SYSTEM) { + iput(inode); + goto fail; + } + + gfs2_glock_dq_uninit(&i_gh); + +out_inode: + dentry = d_alloc_anon(inode); + if (!dentry) { + iput(inode); + return ERR_PTR(-ENOMEM); + } + + return dentry; + +fail_rgd: + gfs2_glock_dq_uninit(&rgd_gh); + +fail_rindex: + gfs2_glock_dq_uninit(&ri_gh); + +fail: + gfs2_glock_dq_uninit(&i_gh); + return ERR_PTR(error); +} + +struct export_operations gfs2_export_ops = { + .decode_fh = gfs2_decode_fh, + .encode_fh = gfs2_encode_fh, + .get_name = gfs2_get_name, + .get_parent = gfs2_get_parent, + .get_dentry = gfs2_get_dentry, +}; + |