diff options
Diffstat (limited to 'fs/gfs2/ops_inode.c')
-rw-r--r-- | fs/gfs2/ops_inode.c | 1196 |
1 files changed, 1196 insertions, 0 deletions
diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c new file mode 100644 index 000000000000..62a12a59d91b --- /dev/null +++ b/fs/gfs2/ops_inode.c @@ -0,0 +1,1196 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2005 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 v.2. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <linux/namei.h> +#include <linux/utsname.h> +#include <linux/mm.h> +#include <linux/xattr.h> +#include <linux/posix_acl.h> +#include <linux/gfs2_ondisk.h> +#include <linux/crc32.h> +#include <asm/semaphore.h> +#include <asm/uaccess.h> + +#include "gfs2.h" +#include "lm_interface.h" +#include "incore.h" +#include "acl.h" +#include "bmap.h" +#include "dir.h" +#include "eaops.h" +#include "eattr.h" +#include "glock.h" +#include "inode.h" +#include "meta_io.h" +#include "ops_dentry.h" +#include "ops_inode.h" +#include "page.h" +#include "quota.h" +#include "rgrp.h" +#include "trans.h" +#include "unlinked.h" +#include "util.h" + +/** + * gfs2_create - Create a file + * @dir: The directory in which to create the file + * @dentry: The dentry of the new file + * @mode: The mode of the new file + * + * Returns: errno + */ + +static int gfs2_create(struct inode *dir, struct dentry *dentry, + int mode, struct nameidata *nd) +{ + struct gfs2_inode *dip = dir->u.generic_ip; + struct gfs2_sbd *sdp = dip->i_sbd; + struct gfs2_holder ghs[2]; + struct inode *inode; + int new = 1; + + gfs2_holder_init(dip->i_gl, 0, 0, ghs); + + for (;;) { + inode = gfs2_createi(ghs, &dentry->d_name, S_IFREG | mode); + if (!IS_ERR(inode)) { + gfs2_trans_end(sdp); + if (dip->i_alloc.al_rgd) + gfs2_inplace_release(dip); + gfs2_quota_unlock(dip); + gfs2_alloc_put(dip); + gfs2_glock_dq_uninit_m(2, ghs); + break; + } else if (PTR_ERR(inode) != -EEXIST || + (nd->intent.open.flags & O_EXCL)) { + gfs2_holder_uninit(ghs); + return PTR_ERR(inode); + } + + inode = gfs2_lookupi(dir, &dentry->d_name, 0, nd); + if (inode) { + if (!IS_ERR(inode)) { + new = 0; + gfs2_holder_uninit(ghs); + break; + } else { + gfs2_holder_uninit(ghs); + return PTR_ERR(inode); + } + } + } + + d_instantiate(dentry, inode); + if (new) + mark_inode_dirty(inode); + + return 0; +} + +/** + * gfs2_lookup - Look up a filename in a directory and return its inode + * @dir: The directory inode + * @dentry: The dentry of the new inode + * @nd: passed from Linux VFS, ignored by us + * + * Called by the VFS layer. Lock dir and call gfs2_lookupi() + * + * Returns: errno + */ + +static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry, + struct nameidata *nd) +{ + struct inode *inode = NULL; + + dentry->d_op = &gfs2_dops; + + inode = gfs2_lookupi(dir, &dentry->d_name, 0, nd); + if (inode && IS_ERR(inode)) + return ERR_PTR(PTR_ERR(inode)); + + if (inode) + return d_splice_alias(inode, dentry); + d_add(dentry, inode); + + return NULL; +} + +/** + * gfs2_link - Link to a file + * @old_dentry: The inode to link + * @dir: Add link to this directory + * @dentry: The name of the link + * + * Link the inode in "old_dentry" into the directory "dir" with the + * name in "dentry". + * + * Returns: errno + */ + +static int gfs2_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *dentry) +{ + struct gfs2_inode *dip = dir->u.generic_ip; + struct gfs2_sbd *sdp = dip->i_sbd; + struct inode *inode = old_dentry->d_inode; + struct gfs2_inode *ip = inode->u.generic_ip; + struct gfs2_holder ghs[2]; + int alloc_required; + int error; + + if (S_ISDIR(ip->i_di.di_mode)) + return -EPERM; + + gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs); + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1); + + error = gfs2_glock_nq_m(2, ghs); + if (error) + goto out; + + error = gfs2_repermission(dir, MAY_WRITE | MAY_EXEC, NULL); + if (error) + goto out_gunlock; + + error = gfs2_dir_search(dir, &dentry->d_name, NULL, NULL); + switch (error) { + case -ENOENT: + break; + case 0: + error = -EEXIST; + default: + goto out_gunlock; + } + + error = -EINVAL; + if (!dip->i_di.di_nlink) + goto out_gunlock; + error = -EFBIG; + if (dip->i_di.di_entries == (uint32_t)-1) + goto out_gunlock; + error = -EPERM; + if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) + goto out_gunlock; + error = -EINVAL; + if (!ip->i_di.di_nlink) + goto out_gunlock; + error = -EMLINK; + if (ip->i_di.di_nlink == (uint32_t)-1) + goto out_gunlock; + + alloc_required = error = gfs2_diradd_alloc_required(dir, &dentry->d_name); + if (error < 0) + goto out_gunlock; + error = 0; + + if (alloc_required) { + struct gfs2_alloc *al = gfs2_alloc_get(dip); + + error = gfs2_quota_lock(dip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); + if (error) + goto out_alloc; + + error = gfs2_quota_check(dip, dip->i_di.di_uid, + dip->i_di.di_gid); + if (error) + goto out_gunlock_q; + + al->al_requested = sdp->sd_max_dirres; + + error = gfs2_inplace_reserve(dip); + if (error) + goto out_gunlock_q; + + error = gfs2_trans_begin(sdp, + sdp->sd_max_dirres + + al->al_rgd->rd_ri.ri_length + + 2 * RES_DINODE + RES_STATFS + + RES_QUOTA, 0); + if (error) + goto out_ipres; + } else { + error = gfs2_trans_begin(sdp, 2 * RES_DINODE + RES_LEAF, 0); + if (error) + goto out_ipres; + } + + error = gfs2_dir_add(dir, &dentry->d_name, &ip->i_num, + IF2DT(ip->i_di.di_mode)); + if (error) + goto out_end_trans; + + error = gfs2_change_nlink(ip, +1); + + out_end_trans: + gfs2_trans_end(sdp); + + out_ipres: + if (alloc_required) + gfs2_inplace_release(dip); + + out_gunlock_q: + if (alloc_required) + gfs2_quota_unlock(dip); + + out_alloc: + if (alloc_required) + gfs2_alloc_put(dip); + + out_gunlock: + gfs2_glock_dq_m(2, ghs); + + out: + gfs2_holder_uninit(ghs); + gfs2_holder_uninit(ghs + 1); + + if (!error) { + atomic_inc(&inode->i_count); + d_instantiate(dentry, inode); + mark_inode_dirty(inode); + } + + return error; +} + +/** + * gfs2_unlink - Unlink a file + * @dir: The inode of the directory containing the file to unlink + * @dentry: The file itself + * + * Unlink a file. Call gfs2_unlinki() + * + * Returns: errno + */ + +static int gfs2_unlink(struct inode *dir, struct dentry *dentry) +{ + struct gfs2_inode *dip = dir->u.generic_ip; + struct gfs2_sbd *sdp = dip->i_sbd; + struct gfs2_inode *ip = dentry->d_inode->u.generic_ip; + struct gfs2_unlinked *ul; + struct gfs2_holder ghs[2]; + int error; + + error = gfs2_unlinked_get(sdp, &ul); + if (error) + return error; + + gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs); + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1); + + error = gfs2_glock_nq_m(2, ghs); + if (error) + goto out; + + error = gfs2_unlink_ok(dip, &dentry->d_name, ip); + if (error) + goto out_gunlock; + + error = gfs2_trans_begin(sdp, 2 * RES_DINODE + RES_LEAF + + RES_UNLINKED, 0); + if (error) + goto out_gunlock; + + error = gfs2_unlinki(dip, &dentry->d_name, ip,ul); + + gfs2_trans_end(sdp); + + out_gunlock: + gfs2_glock_dq_m(2, ghs); + + out: + gfs2_holder_uninit(ghs); + gfs2_holder_uninit(ghs + 1); + + gfs2_unlinked_put(sdp, ul); + + return error; +} + +/** + * gfs2_symlink - Create a symlink + * @dir: The directory to create the symlink in + * @dentry: The dentry to put the symlink in + * @symname: The thing which the link points to + * + * Returns: errno + */ + +static int gfs2_symlink(struct inode *dir, struct dentry *dentry, + const char *symname) +{ + struct gfs2_inode *dip = dir->u.generic_ip, *ip; + struct gfs2_sbd *sdp = dip->i_sbd; + struct gfs2_holder ghs[2]; + struct inode *inode; + struct buffer_head *dibh; + int size; + int error; + + /* Must be stuffed with a null terminator for gfs2_follow_link() */ + size = strlen(symname); + if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode) - 1) + return -ENAMETOOLONG; + + gfs2_holder_init(dip->i_gl, 0, 0, ghs); + + inode = gfs2_createi(ghs, &dentry->d_name, S_IFLNK | S_IRWXUGO); + if (IS_ERR(inode)) { + gfs2_holder_uninit(ghs); + return PTR_ERR(inode); + } + + ip = ghs[1].gh_gl->gl_object; + + ip->i_di.di_size = size; + + error = gfs2_meta_inode_buffer(ip, &dibh); + + if (!gfs2_assert_withdraw(sdp, !error)) { + gfs2_dinode_out(&ip->i_di, dibh->b_data); + memcpy(dibh->b_data + sizeof(struct gfs2_dinode), symname, + size); + brelse(dibh); + } + + gfs2_trans_end(sdp); + if (dip->i_alloc.al_rgd) + gfs2_inplace_release(dip); + gfs2_quota_unlock(dip); + gfs2_alloc_put(dip); + + gfs2_glock_dq_uninit_m(2, ghs); + + d_instantiate(dentry, inode); + mark_inode_dirty(inode); + + return 0; +} + +/** + * gfs2_mkdir - Make a directory + * @dir: The parent directory of the new one + * @dentry: The dentry of the new directory + * @mode: The mode of the new directory + * + * Returns: errno + */ + +static int gfs2_mkdir(struct inode *dir, struct dentry *dentry, int mode) +{ + struct gfs2_inode *dip = dir->u.generic_ip, *ip; + struct gfs2_sbd *sdp = dip->i_sbd; + struct gfs2_holder ghs[2]; + struct inode *inode; + struct buffer_head *dibh; + int error; + + gfs2_holder_init(dip->i_gl, 0, 0, ghs); + + inode = gfs2_createi(ghs, &dentry->d_name, S_IFDIR | mode); + if (IS_ERR(inode)) { + gfs2_holder_uninit(ghs); + return PTR_ERR(inode); + } + + ip = ghs[1].gh_gl->gl_object; + + ip->i_di.di_nlink = 2; + ip->i_di.di_size = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode); + ip->i_di.di_flags |= GFS2_DIF_JDATA; + ip->i_di.di_payload_format = GFS2_FORMAT_DE; + ip->i_di.di_entries = 2; + + error = gfs2_meta_inode_buffer(ip, &dibh); + + if (!gfs2_assert_withdraw(sdp, !error)) { + struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data; + struct gfs2_dirent *dent = (struct gfs2_dirent *)(di+1); + struct qstr str; + + gfs2_str2qstr(&str, "."); + gfs2_trans_add_bh(ip->i_gl, dibh, 1); + gfs2_qstr2dirent(&str, GFS2_DIRENT_SIZE(str.len), dent); + dent->de_inum = di->di_num; /* already GFS2 endian */ + dent->de_type = DT_DIR; + di->di_entries = cpu_to_be32(1); + + gfs2_str2qstr(&str, ".."); + dent = (struct gfs2_dirent *)((char*)dent + GFS2_DIRENT_SIZE(1)); + gfs2_qstr2dirent(&str, dibh->b_size - GFS2_DIRENT_SIZE(1) - sizeof(struct gfs2_dinode), dent); + + gfs2_inum_out(&dip->i_num, (char *) &dent->de_inum); + dent->de_type = DT_DIR; + + gfs2_dinode_out(&ip->i_di, (char *)di); + + brelse(dibh); + } + + error = gfs2_change_nlink(dip, +1); + gfs2_assert_withdraw(sdp, !error); /* dip already pinned */ + + gfs2_trans_end(sdp); + if (dip->i_alloc.al_rgd) + gfs2_inplace_release(dip); + gfs2_quota_unlock(dip); + gfs2_alloc_put(dip); + + gfs2_glock_dq_uninit_m(2, ghs); + + d_instantiate(dentry, inode); + mark_inode_dirty(inode); + + return 0; +} + +/** + * gfs2_rmdir - Remove a directory + * @dir: The parent directory of the directory to be removed + * @dentry: The dentry of the directory to remove + * + * Remove a directory. Call gfs2_rmdiri() + * + * Returns: errno + */ + +static int gfs2_rmdir(struct inode *dir, struct dentry *dentry) +{ + struct gfs2_inode *dip = dir->u.generic_ip; + struct gfs2_sbd *sdp = dip->i_sbd; + struct gfs2_inode *ip = dentry->d_inode->u.generic_ip; + struct gfs2_unlinked *ul; + struct gfs2_holder ghs[2]; + int error; + + error = gfs2_unlinked_get(sdp, &ul); + if (error) + return error; + + gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs); + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1); + + error = gfs2_glock_nq_m(2, ghs); + if (error) + goto out; + + error = gfs2_unlink_ok(dip, &dentry->d_name, ip); + if (error) + goto out_gunlock; + + if (ip->i_di.di_entries < 2) { + if (gfs2_consist_inode(ip)) + gfs2_dinode_print(&ip->i_di); + error = -EIO; + goto out_gunlock; + } + if (ip->i_di.di_entries > 2) { + error = -ENOTEMPTY; + goto out_gunlock; + } + + error = gfs2_trans_begin(sdp, 2 * RES_DINODE + 3 * RES_LEAF + + RES_UNLINKED, 0); + if (error) + goto out_gunlock; + + error = gfs2_rmdiri(dip, &dentry->d_name, ip, ul); + + gfs2_trans_end(sdp); + + out_gunlock: + gfs2_glock_dq_m(2, ghs); + + out: + gfs2_holder_uninit(ghs); + gfs2_holder_uninit(ghs + 1); + + gfs2_unlinked_put(sdp, ul); + + return error; +} + +/** + * gfs2_mknod - Make a special file + * @dir: The directory in which the special file will reside + * @dentry: The dentry of the special file + * @mode: The mode of the special file + * @rdev: The device specification of the special file + * + */ + +static int gfs2_mknod(struct inode *dir, struct dentry *dentry, int mode, + dev_t dev) +{ + struct gfs2_inode *dip = dir->u.generic_ip, *ip; + struct gfs2_sbd *sdp = dip->i_sbd; + struct gfs2_holder ghs[2]; + struct inode *inode; + struct buffer_head *dibh; + uint32_t major = 0, minor = 0; + int error; + + switch (mode & S_IFMT) { + case S_IFBLK: + case S_IFCHR: + major = MAJOR(dev); + minor = MINOR(dev); + break; + case S_IFIFO: + case S_IFSOCK: + break; + default: + return -EOPNOTSUPP; + }; + + gfs2_holder_init(dip->i_gl, 0, 0, ghs); + + inode = gfs2_createi(ghs, &dentry->d_name, mode); + if (IS_ERR(inode)) { + gfs2_holder_uninit(ghs); + return PTR_ERR(inode); + } + + ip = ghs[1].gh_gl->gl_object; + + ip->i_di.di_major = major; + ip->i_di.di_minor = minor; + + error = gfs2_meta_inode_buffer(ip, &dibh); + + if (!gfs2_assert_withdraw(sdp, !error)) { + gfs2_dinode_out(&ip->i_di, dibh->b_data); + brelse(dibh); + } + + gfs2_trans_end(sdp); + if (dip->i_alloc.al_rgd) + gfs2_inplace_release(dip); + gfs2_quota_unlock(dip); + gfs2_alloc_put(dip); + + gfs2_glock_dq_uninit_m(2, ghs); + + d_instantiate(dentry, inode); + mark_inode_dirty(inode); + + return 0; +} + +/** + * gfs2_rename - Rename a file + * @odir: Parent directory of old file name + * @odentry: The old dentry of the file + * @ndir: Parent directory of new file name + * @ndentry: The new dentry of the file + * + * Returns: errno + */ + +static int gfs2_rename(struct inode *odir, struct dentry *odentry, + struct inode *ndir, struct dentry *ndentry) +{ + struct gfs2_inode *odip = odir->u.generic_ip; + struct gfs2_inode *ndip = ndir->u.generic_ip; + struct gfs2_inode *ip = odentry->d_inode->u.generic_ip; + struct gfs2_inode *nip = NULL; + struct gfs2_sbd *sdp = odip->i_sbd; + struct gfs2_unlinked *ul; + struct gfs2_holder ghs[4], r_gh; + unsigned int num_gh; + int dir_rename = 0; + int alloc_required; + unsigned int x; + int error; + + if (ndentry->d_inode) { + nip = ndentry->d_inode->u.generic_ip; + if (ip == nip) + return 0; + } + + error = gfs2_unlinked_get(sdp, &ul); + if (error) + return error; + + /* Make sure we aren't trying to move a dirctory into it's subdir */ + + if (S_ISDIR(ip->i_di.di_mode) && odip != ndip) { + dir_rename = 1; + + error = gfs2_glock_nq_init(sdp->sd_rename_gl, + LM_ST_EXCLUSIVE, 0, + &r_gh); + if (error) + goto out; + + error = gfs2_ok_to_move(ip, ndip); + if (error) + goto out_gunlock_r; + } + + gfs2_holder_init(odip->i_gl, LM_ST_EXCLUSIVE, 0, ghs); + gfs2_holder_init(ndip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1); + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 2); + num_gh = 3; + + if (nip) + gfs2_holder_init(nip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh++); + + error = gfs2_glock_nq_m(num_gh, ghs); + if (error) + goto out_uninit; + + /* Check out the old directory */ + + error = gfs2_unlink_ok(odip, &odentry->d_name, ip); + if (error) + goto out_gunlock; + + /* Check out the new directory */ + + if (nip) { + error = gfs2_unlink_ok(ndip, &ndentry->d_name, nip); + if (error) + goto out_gunlock; + + if (S_ISDIR(nip->i_di.di_mode)) { + if (nip->i_di.di_entries < 2) { + if (gfs2_consist_inode(nip)) + gfs2_dinode_print(&nip->i_di); + error = -EIO; + goto out_gunlock; + } + if (nip->i_di.di_entries > 2) { + error = -ENOTEMPTY; + goto out_gunlock; + } + } + } else { + error = gfs2_repermission(ndir, MAY_WRITE | MAY_EXEC, NULL); + if (error) + goto out_gunlock; + + error = gfs2_dir_search(ndir, &ndentry->d_name, NULL, NULL); + switch (error) { + case -ENOENT: + error = 0; + break; + case 0: + error = -EEXIST; + default: + goto out_gunlock; + }; + + if (odip != ndip) { + if (!ndip->i_di.di_nlink) { + error = -EINVAL; + goto out_gunlock; + } + if (ndip->i_di.di_entries == (uint32_t)-1) { + error = -EFBIG; + goto out_gunlock; + } + if (S_ISDIR(ip->i_di.di_mode) && + ndip->i_di.di_nlink == (uint32_t)-1) { + error = -EMLINK; + goto out_gunlock; + } + } + } + + /* Check out the dir to be renamed */ + + if (dir_rename) { + error = gfs2_repermission(odentry->d_inode, MAY_WRITE, NULL); + if (error) + goto out_gunlock; + } + + alloc_required = error = gfs2_diradd_alloc_required(ndir, &ndentry->d_name); + if (error < 0) + goto out_gunlock; + error = 0; + + if (alloc_required) { + struct gfs2_alloc *al = gfs2_alloc_get(ndip); + + error = gfs2_quota_lock(ndip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); + if (error) + goto out_alloc; + + error = gfs2_quota_check(ndip, ndip->i_di.di_uid, + ndip->i_di.di_gid); + if (error) + goto out_gunlock_q; + + al->al_requested = sdp->sd_max_dirres; + + error = gfs2_inplace_reserve(ndip); + if (error) + goto out_gunlock_q; + + error = gfs2_trans_begin(sdp, sdp->sd_max_dirres + + al->al_rgd->rd_ri.ri_length + + 4 * RES_DINODE + 4 * RES_LEAF + + RES_UNLINKED + RES_STATFS + + RES_QUOTA, 0); + if (error) + goto out_ipreserv; + } else { + error = gfs2_trans_begin(sdp, 4 * RES_DINODE + + 5 * RES_LEAF + + RES_UNLINKED, 0); + if (error) + goto out_gunlock; + } + + /* Remove the target file, if it exists */ + + if (nip) { + if (S_ISDIR(nip->i_di.di_mode)) + error = gfs2_rmdiri(ndip, &ndentry->d_name, nip, ul); + else + error = gfs2_unlinki(ndip, &ndentry->d_name, nip, ul); + if (error) + goto out_end_trans; + } + + if (dir_rename) { + struct qstr name; + gfs2_str2qstr(&name, ".."); + + error = gfs2_change_nlink(ndip, +1); + if (error) + goto out_end_trans; + error = gfs2_change_nlink(odip, -1); + if (error) + goto out_end_trans; + + error = gfs2_dir_mvino(ip, &name, &ndip->i_num, DT_DIR); + if (error) + goto out_end_trans; + } else { + struct buffer_head *dibh; + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + goto out_end_trans; + ip->i_di.di_ctime = get_seconds(); + gfs2_trans_add_bh(ip->i_gl, dibh, 1); + gfs2_dinode_out(&ip->i_di, dibh->b_data); + brelse(dibh); + } + + error = gfs2_dir_del(odip, &odentry->d_name); + if (error) + goto out_end_trans; + + error = gfs2_dir_add(ndir, &ndentry->d_name, &ip->i_num, + IF2DT(ip->i_di.di_mode)); + if (error) + goto out_end_trans; + + out_end_trans: + gfs2_trans_end(sdp); + + out_ipreserv: + if (alloc_required) + gfs2_inplace_release(ndip); + + out_gunlock_q: + if (alloc_required) + gfs2_quota_unlock(ndip); + + out_alloc: + if (alloc_required) + gfs2_alloc_put(ndip); + + out_gunlock: + gfs2_glock_dq_m(num_gh, ghs); + + out_uninit: + for (x = 0; x < num_gh; x++) + gfs2_holder_uninit(ghs + x); + + out_gunlock_r: + if (dir_rename) + gfs2_glock_dq_uninit(&r_gh); + + out: + gfs2_unlinked_put(sdp, ul); + + return error; +} + +/** + * gfs2_readlink - Read the value of a symlink + * @dentry: the symlink + * @buf: the buffer to read the symlink data into + * @size: the size of the buffer + * + * Returns: errno + */ + +static int gfs2_readlink(struct dentry *dentry, char __user *user_buf, + int user_size) +{ + struct gfs2_inode *ip = dentry->d_inode->u.generic_ip; + char array[GFS2_FAST_NAME_SIZE], *buf = array; + unsigned int len = GFS2_FAST_NAME_SIZE; + int error; + + error = gfs2_readlinki(ip, &buf, &len); + if (error) + return error; + + if (user_size > len - 1) + user_size = len - 1; + + if (copy_to_user(user_buf, buf, user_size)) + error = -EFAULT; + else + error = user_size; + + if (buf != array) + kfree(buf); + + return error; +} + +/** + * gfs2_follow_link - Follow a symbolic link + * @dentry: The dentry of the link + * @nd: Data that we pass to vfs_follow_link() + * + * This can handle symlinks of any size. It is optimised for symlinks + * under GFS2_FAST_NAME_SIZE. + * + * Returns: 0 on success or error code + */ + +static void *gfs2_follow_link(struct dentry *dentry, struct nameidata *nd) +{ + struct gfs2_inode *ip = dentry->d_inode->u.generic_ip; + char array[GFS2_FAST_NAME_SIZE], *buf = array; + unsigned int len = GFS2_FAST_NAME_SIZE; + int error; + + error = gfs2_readlinki(ip, &buf, &len); + if (!error) { + error = vfs_follow_link(nd, buf); + if (buf != array) + kfree(buf); + } + + return ERR_PTR(error); +} + +/** + * gfs2_permission - + * @inode: + * @mask: + * @nd: passed from Linux VFS, ignored by us + * + * Returns: errno + */ + +static int gfs2_permission(struct inode *inode, int mask, struct nameidata *nd) +{ + struct gfs2_inode *ip = inode->u.generic_ip; + struct gfs2_holder i_gh; + int error; + + if (ip->i_vn == ip->i_gl->gl_vn) + return generic_permission(inode, mask, gfs2_check_acl); + + error = gfs2_glock_nq_init(ip->i_gl, + LM_ST_SHARED, LM_FLAG_ANY, + &i_gh); + if (!error) { + error = generic_permission(inode, mask, gfs2_check_acl_locked); + gfs2_glock_dq_uninit(&i_gh); + } + + return error; +} + +static int setattr_size(struct inode *inode, struct iattr *attr) +{ + struct gfs2_inode *ip = inode->u.generic_ip; + int error; + + if (attr->ia_size != ip->i_di.di_size) { + error = vmtruncate(inode, attr->ia_size); + if (error) + return error; + } + + error = gfs2_truncatei(ip, attr->ia_size); + if (error) + return error; + + return error; +} + +static int setattr_chown(struct inode *inode, struct iattr *attr) +{ + struct gfs2_inode *ip = inode->u.generic_ip; + struct gfs2_sbd *sdp = ip->i_sbd; + struct buffer_head *dibh; + uint32_t ouid, ogid, nuid, ngid; + int error; + + ouid = ip->i_di.di_uid; + ogid = ip->i_di.di_gid; + nuid = attr->ia_uid; + ngid = attr->ia_gid; + + if (!(attr->ia_valid & ATTR_UID) || ouid == nuid) + ouid = nuid = NO_QUOTA_CHANGE; + if (!(attr->ia_valid & ATTR_GID) || ogid == ngid) + ogid = ngid = NO_QUOTA_CHANGE; + + gfs2_alloc_get(ip); + + error = gfs2_quota_lock(ip, nuid, ngid); + if (error) + goto out_alloc; + + if (ouid != NO_QUOTA_CHANGE || ogid != NO_QUOTA_CHANGE) { + error = gfs2_quota_check(ip, nuid, ngid); + if (error) + goto out_gunlock_q; + } + + error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_QUOTA, 0); + if (error) + goto out_gunlock_q; + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + goto out_end_trans; + + error = inode_setattr(inode, attr); + gfs2_assert_warn(sdp, !error); + gfs2_inode_attr_out(ip); + + gfs2_trans_add_bh(ip->i_gl, dibh, 1); + gfs2_dinode_out(&ip->i_di, dibh->b_data); + brelse(dibh); + + if (ouid != NO_QUOTA_CHANGE || ogid != NO_QUOTA_CHANGE) { + gfs2_quota_change(ip, -ip->i_di.di_blocks, + ouid, ogid); + gfs2_quota_change(ip, ip->i_di.di_blocks, + nuid, ngid); + } + + out_end_trans: + gfs2_trans_end(sdp); + + out_gunlock_q: + gfs2_quota_unlock(ip); + + out_alloc: + gfs2_alloc_put(ip); + + return error; +} + +/** + * gfs2_setattr - Change attributes on an inode + * @dentry: The dentry which is changing + * @attr: The structure describing the change + * + * The VFS layer wants to change one or more of an inodes attributes. Write + * that change out to disk. + * + * Returns: errno + */ + +static int gfs2_setattr(struct dentry *dentry, struct iattr *attr) +{ + struct inode *inode = dentry->d_inode; + struct gfs2_inode *ip = inode->u.generic_ip; + struct gfs2_holder i_gh; + int error; + + error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh); + if (error) + return error; + + error = -EPERM; + if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) + goto out; + + error = inode_change_ok(inode, attr); + if (error) + goto out; + + if (attr->ia_valid & ATTR_SIZE) + error = setattr_size(inode, attr); + else if (attr->ia_valid & (ATTR_UID | ATTR_GID)) + error = setattr_chown(inode, attr); + else if ((attr->ia_valid & ATTR_MODE) && IS_POSIXACL(inode)) + error = gfs2_acl_chmod(ip, attr); + else + error = gfs2_setattr_simple(ip, attr); + + out: + gfs2_glock_dq_uninit(&i_gh); + + if (!error) + mark_inode_dirty(inode); + + return error; +} + +/** + * gfs2_getattr - Read out an inode's attributes + * @mnt: ? + * @dentry: The dentry to stat + * @stat: The inode's stats + * + * Returns: errno + */ + +static int gfs2_getattr(struct vfsmount *mnt, struct dentry *dentry, + struct kstat *stat) +{ + struct inode *inode = dentry->d_inode; + struct gfs2_inode *ip = inode->u.generic_ip; + struct gfs2_holder gh; + int error; + + error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh); + if (!error) { + generic_fillattr(inode, stat); + gfs2_glock_dq_uninit(&gh); + } + + return error; +} + +static int gfs2_setxattr(struct dentry *dentry, const char *name, + const void *data, size_t size, int flags) +{ + struct gfs2_inode *ip = dentry->d_inode->u.generic_ip; + struct gfs2_ea_request er; + + memset(&er, 0, sizeof(struct gfs2_ea_request)); + er.er_type = gfs2_ea_name2type(name, &er.er_name); + if (er.er_type == GFS2_EATYPE_UNUSED) + return -EOPNOTSUPP; + er.er_data = (char *)data; + er.er_name_len = strlen(er.er_name); + er.er_data_len = size; + er.er_flags = flags; + + gfs2_assert_warn(ip->i_sbd, !(er.er_flags & GFS2_ERF_MODE)); + + return gfs2_ea_set(ip, &er); +} + +static ssize_t gfs2_getxattr(struct dentry *dentry, const char *name, + void *data, size_t size) +{ + struct gfs2_ea_request er; + + memset(&er, 0, sizeof(struct gfs2_ea_request)); + er.er_type = gfs2_ea_name2type(name, &er.er_name); + if (er.er_type == GFS2_EATYPE_UNUSED) + return -EOPNOTSUPP; + er.er_data = data; + er.er_name_len = strlen(er.er_name); + er.er_data_len = size; + + return gfs2_ea_get(dentry->d_inode->u.generic_ip, &er); +} + +static ssize_t gfs2_listxattr(struct dentry *dentry, char *buffer, size_t size) +{ + struct gfs2_ea_request er; + + memset(&er, 0, sizeof(struct gfs2_ea_request)); + er.er_data = (size) ? buffer : NULL; + er.er_data_len = size; + + return gfs2_ea_list(dentry->d_inode->u.generic_ip, &er); +} + +static int gfs2_removexattr(struct dentry *dentry, const char *name) +{ + struct gfs2_ea_request er; + + memset(&er, 0, sizeof(struct gfs2_ea_request)); + er.er_type = gfs2_ea_name2type(name, &er.er_name); + if (er.er_type == GFS2_EATYPE_UNUSED) + return -EOPNOTSUPP; + er.er_name_len = strlen(er.er_name); + + return gfs2_ea_remove(dentry->d_inode->u.generic_ip, &er); +} + +struct inode_operations gfs2_file_iops = { + .permission = gfs2_permission, + .setattr = gfs2_setattr, + .getattr = gfs2_getattr, + .setxattr = gfs2_setxattr, + .getxattr = gfs2_getxattr, + .listxattr = gfs2_listxattr, + .removexattr = gfs2_removexattr, +}; + +struct inode_operations gfs2_dev_iops = { + .permission = gfs2_permission, + .setattr = gfs2_setattr, + .getattr = gfs2_getattr, + .setxattr = gfs2_setxattr, + .getxattr = gfs2_getxattr, + .listxattr = gfs2_listxattr, + .removexattr = gfs2_removexattr, +}; + +struct inode_operations gfs2_dir_iops = { + .create = gfs2_create, + .lookup = gfs2_lookup, + .link = gfs2_link, + .unlink = gfs2_unlink, + .symlink = gfs2_symlink, + .mkdir = gfs2_mkdir, + .rmdir = gfs2_rmdir, + .mknod = gfs2_mknod, + .rename = gfs2_rename, + .permission = gfs2_permission, + .setattr = gfs2_setattr, + .getattr = gfs2_getattr, + .setxattr = gfs2_setxattr, + .getxattr = gfs2_getxattr, + .listxattr = gfs2_listxattr, + .removexattr = gfs2_removexattr, +}; + +struct inode_operations gfs2_symlink_iops = { + .readlink = gfs2_readlink, + .follow_link = gfs2_follow_link, + .permission = gfs2_permission, + .setattr = gfs2_setattr, + .getattr = gfs2_getattr, + .setxattr = gfs2_setxattr, + .getxattr = gfs2_getxattr, + .listxattr = gfs2_listxattr, + .removexattr = gfs2_removexattr, +}; + |