/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (C) 2011 Lawrence Livermore National Security, LLC. * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER). * LLNL-CODE-403049. * Rewritten for Linux by: * Rohan Puri <rohan.puri15@gmail.com> * Brian Behlendorf <behlendorf1@llnl.gov> */ #include <sys/zfs_vfsops.h> #include <sys/zfs_vnops.h> #include <sys/zfs_znode.h> #include <sys/zfs_ctldir.h> #include <sys/zpl.h> /* * Common open routine. Disallow any write access. */ /* ARGSUSED */ static int zpl_common_open(struct inode *ip, struct file *filp) { if (filp->f_mode & FMODE_WRITE) return (-EACCES); return (generic_file_open(ip, filp)); } /* * Get root directory contents. */ static int zpl_root_iterate(struct file *filp, zpl_dir_context_t *ctx) { zfsvfs_t *zfsvfs = ITOZSB(file_inode(filp)); int error = 0; ZFS_ENTER(zfsvfs); if (!zpl_dir_emit_dots(filp, ctx)) goto out; if (ctx->pos == 2) { if (!zpl_dir_emit(ctx, ZFS_SNAPDIR_NAME, strlen(ZFS_SNAPDIR_NAME), ZFSCTL_INO_SNAPDIR, DT_DIR)) goto out; ctx->pos++; } if (ctx->pos == 3) { if (!zpl_dir_emit(ctx, ZFS_SHAREDIR_NAME, strlen(ZFS_SHAREDIR_NAME), ZFSCTL_INO_SHARES, DT_DIR)) goto out; ctx->pos++; } out: ZFS_EXIT(zfsvfs); return (error); } #if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED) static int zpl_root_readdir(struct file *filp, void *dirent, filldir_t filldir) { zpl_dir_context_t ctx = ZPL_DIR_CONTEXT_INIT(dirent, filldir, filp->f_pos); int error; error = zpl_root_iterate(filp, &ctx); filp->f_pos = ctx.pos; return (error); } #endif /* !HAVE_VFS_ITERATE && !HAVE_VFS_ITERATE_SHARED */ /* * Get root directory attributes. */ /* ARGSUSED */ static int zpl_root_getattr_impl(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { struct inode *ip = path->dentry->d_inode; generic_fillattr(ip, stat); stat->atime = current_time(ip); return (0); } ZPL_GETATTR_WRAPPER(zpl_root_getattr); static struct dentry * #ifdef HAVE_LOOKUP_NAMEIDATA zpl_root_lookup(struct inode *dip, struct dentry *dentry, struct nameidata *nd) #else zpl_root_lookup(struct inode *dip, struct dentry *dentry, unsigned int flags) #endif { cred_t *cr = CRED(); struct inode *ip; int error; crhold(cr); error = -zfsctl_root_lookup(dip, dname(dentry), &ip, 0, cr, NULL, NULL); ASSERT3S(error, <=, 0); crfree(cr); if (error) { if (error == -ENOENT) return (d_splice_alias(NULL, dentry)); else return (ERR_PTR(error)); } return (d_splice_alias(ip, dentry)); } /* * The '.zfs' control directory file and inode operations. */ const struct file_operations zpl_fops_root = { .open = zpl_common_open, .llseek = generic_file_llseek, .read = generic_read_dir, #ifdef HAVE_VFS_ITERATE_SHARED .iterate_shared = zpl_root_iterate, #elif defined(HAVE_VFS_ITERATE) .iterate = zpl_root_iterate, #else .readdir = zpl_root_readdir, #endif }; const struct inode_operations zpl_ops_root = { .lookup = zpl_root_lookup, .getattr = zpl_root_getattr, }; #ifdef HAVE_AUTOMOUNT static struct vfsmount * zpl_snapdir_automount(struct path *path) { int error; error = -zfsctl_snapshot_mount(path, 0); if (error) return (ERR_PTR(error)); /* * Rather than returning the new vfsmount for the snapshot we must * return NULL to indicate a mount collision. This is done because * the user space mount calls do_add_mount() which adds the vfsmount * to the name space. If we returned the new mount here it would be * added again to the vfsmount list resulting in list corruption. */ return (NULL); } #endif /* HAVE_AUTOMOUNT */ /* * Negative dentries must always be revalidated so newly created snapshots * can be detected and automounted. Normal dentries should be kept because * as of the 3.18 kernel revaliding the mountpoint dentry will result in * the snapshot being immediately unmounted. */ static int #ifdef HAVE_D_REVALIDATE_NAMEIDATA zpl_snapdir_revalidate(struct dentry *dentry, struct nameidata *i) #else zpl_snapdir_revalidate(struct dentry *dentry, unsigned int flags) #endif { return (!!dentry->d_inode); } dentry_operations_t zpl_dops_snapdirs = { /* * Auto mounting of snapshots is only supported for 2.6.37 and * newer kernels. Prior to this kernel the ops->follow_link() * callback was used as a hack to trigger the mount. The * resulting vfsmount was then explicitly grafted in to the * name space. While it might be possible to add compatibility * code to accomplish this it would require considerable care. */ #ifdef HAVE_AUTOMOUNT .d_automount = zpl_snapdir_automount, #endif /* HAVE_AUTOMOUNT */ .d_revalidate = zpl_snapdir_revalidate, }; static struct dentry * #ifdef HAVE_LOOKUP_NAMEIDATA zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry, struct nameidata *nd) #else zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry, unsigned int flags) #endif { fstrans_cookie_t cookie; cred_t *cr = CRED(); struct inode *ip = NULL; int error; crhold(cr); cookie = spl_fstrans_mark(); error = -zfsctl_snapdir_lookup(dip, dname(dentry), &ip, 0, cr, NULL, NULL); ASSERT3S(error, <=, 0); spl_fstrans_unmark(cookie); crfree(cr); if (error && error != -ENOENT) return (ERR_PTR(error)); ASSERT(error == 0 || ip == NULL); d_clear_d_op(dentry); d_set_d_op(dentry, &zpl_dops_snapdirs); #ifdef HAVE_AUTOMOUNT dentry->d_flags |= DCACHE_NEED_AUTOMOUNT; #endif return (d_splice_alias(ip, dentry)); } static int zpl_snapdir_iterate(struct file *filp, zpl_dir_context_t *ctx) { zfsvfs_t *zfsvfs = ITOZSB(file_inode(filp)); fstrans_cookie_t cookie; char snapname[MAXNAMELEN]; boolean_t case_conflict; uint64_t id, pos; int error = 0; ZFS_ENTER(zfsvfs); cookie = spl_fstrans_mark(); if (!zpl_dir_emit_dots(filp, ctx)) goto out; pos = ctx->pos; while (error == 0) { dsl_pool_config_enter(dmu_objset_pool(zfsvfs->z_os), FTAG); error = -dmu_snapshot_list_next(zfsvfs->z_os, MAXNAMELEN, snapname, &id, &pos, &case_conflict); dsl_pool_config_exit(dmu_objset_pool(zfsvfs->z_os), FTAG); if (error) goto out; if (!zpl_dir_emit(ctx, snapname, strlen(snapname), ZFSCTL_INO_SHARES - id, DT_DIR)) goto out; ctx->pos = pos; } out: spl_fstrans_unmark(cookie); ZFS_EXIT(zfsvfs); if (error == -ENOENT) return (0); return (error); } #if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED) static int zpl_snapdir_readdir(struct file *filp, void *dirent, filldir_t filldir) { zpl_dir_context_t ctx = ZPL_DIR_CONTEXT_INIT(dirent, filldir, filp->f_pos); int error; error = zpl_snapdir_iterate(filp, &ctx); filp->f_pos = ctx.pos; return (error); } #endif /* !HAVE_VFS_ITERATE && !HAVE_VFS_ITERATE_SHARED */ static int zpl_snapdir_rename2(struct inode *sdip, struct dentry *sdentry, struct inode *tdip, struct dentry *tdentry, unsigned int flags) { cred_t *cr = CRED(); int error; /* We probably don't want to support renameat2(2) in ctldir */ if (flags) return (-EINVAL); crhold(cr); error = -zfsctl_snapdir_rename(sdip, dname(sdentry), tdip, dname(tdentry), cr, 0); ASSERT3S(error, <=, 0); crfree(cr); return (error); } #ifndef HAVE_RENAME_WANTS_FLAGS static int zpl_snapdir_rename(struct inode *sdip, struct dentry *sdentry, struct inode *tdip, struct dentry *tdentry) { return (zpl_snapdir_rename2(sdip, sdentry, tdip, tdentry, 0)); } #endif static int zpl_snapdir_rmdir(struct inode *dip, struct dentry *dentry) { cred_t *cr = CRED(); int error; crhold(cr); error = -zfsctl_snapdir_remove(dip, dname(dentry), cr, 0); ASSERT3S(error, <=, 0); crfree(cr); return (error); } static int zpl_snapdir_mkdir(struct inode *dip, struct dentry *dentry, zpl_umode_t mode) { cred_t *cr = CRED(); vattr_t *vap; struct inode *ip; int error; crhold(cr); vap = kmem_zalloc(sizeof (vattr_t), KM_SLEEP); zpl_vap_init(vap, dip, mode | S_IFDIR, cr); error = -zfsctl_snapdir_mkdir(dip, dname(dentry), vap, &ip, cr, 0); if (error == 0) { d_clear_d_op(dentry); d_set_d_op(dentry, &zpl_dops_snapdirs); d_instantiate(dentry, ip); } kmem_free(vap, sizeof (vattr_t)); ASSERT3S(error, <=, 0); crfree(cr); return (error); } /* * Get snapshot directory attributes. */ /* ARGSUSED */ static int zpl_snapdir_getattr_impl(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { struct inode *ip = path->dentry->d_inode; zfsvfs_t *zfsvfs = ITOZSB(ip); ZFS_ENTER(zfsvfs); generic_fillattr(ip, stat); stat->nlink = stat->size = 2; stat->ctime = stat->mtime = dmu_objset_snap_cmtime(zfsvfs->z_os); stat->atime = current_time(ip); ZFS_EXIT(zfsvfs); return (0); } ZPL_GETATTR_WRAPPER(zpl_snapdir_getattr); /* * The '.zfs/snapshot' directory file operations. These mainly control * generating the list of available snapshots when doing an 'ls' in the * directory. See zpl_snapdir_readdir(). */ const struct file_operations zpl_fops_snapdir = { .open = zpl_common_open, .llseek = generic_file_llseek, .read = generic_read_dir, #ifdef HAVE_VFS_ITERATE_SHARED .iterate_shared = zpl_snapdir_iterate, #elif defined(HAVE_VFS_ITERATE) .iterate = zpl_snapdir_iterate, #else .readdir = zpl_snapdir_readdir, #endif }; /* * The '.zfs/snapshot' directory inode operations. These mainly control * creating an inode for a snapshot directory and initializing the needed * infrastructure to automount the snapshot. See zpl_snapdir_lookup(). */ const struct inode_operations zpl_ops_snapdir = { .lookup = zpl_snapdir_lookup, .getattr = zpl_snapdir_getattr, #ifdef HAVE_RENAME_WANTS_FLAGS .rename = zpl_snapdir_rename2, #else .rename = zpl_snapdir_rename, #endif .rmdir = zpl_snapdir_rmdir, .mkdir = zpl_snapdir_mkdir, }; static struct dentry * #ifdef HAVE_LOOKUP_NAMEIDATA zpl_shares_lookup(struct inode *dip, struct dentry *dentry, struct nameidata *nd) #else zpl_shares_lookup(struct inode *dip, struct dentry *dentry, unsigned int flags) #endif { fstrans_cookie_t cookie; cred_t *cr = CRED(); struct inode *ip = NULL; int error; crhold(cr); cookie = spl_fstrans_mark(); error = -zfsctl_shares_lookup(dip, dname(dentry), &ip, 0, cr, NULL, NULL); ASSERT3S(error, <=, 0); spl_fstrans_unmark(cookie); crfree(cr); if (error) { if (error == -ENOENT) return (d_splice_alias(NULL, dentry)); else return (ERR_PTR(error)); } return (d_splice_alias(ip, dentry)); } static int zpl_shares_iterate(struct file *filp, zpl_dir_context_t *ctx) { fstrans_cookie_t cookie; cred_t *cr = CRED(); zfsvfs_t *zfsvfs = ITOZSB(file_inode(filp)); znode_t *dzp; int error = 0; ZFS_ENTER(zfsvfs); cookie = spl_fstrans_mark(); if (zfsvfs->z_shares_dir == 0) { zpl_dir_emit_dots(filp, ctx); goto out; } error = -zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp); if (error) goto out; crhold(cr); error = -zfs_readdir(ZTOI(dzp), ctx, cr); crfree(cr); iput(ZTOI(dzp)); out: spl_fstrans_unmark(cookie); ZFS_EXIT(zfsvfs); ASSERT3S(error, <=, 0); return (error); } #if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED) static int zpl_shares_readdir(struct file *filp, void *dirent, filldir_t filldir) { zpl_dir_context_t ctx = ZPL_DIR_CONTEXT_INIT(dirent, filldir, filp->f_pos); int error; error = zpl_shares_iterate(filp, &ctx); filp->f_pos = ctx.pos; return (error); } #endif /* !HAVE_VFS_ITERATE && !HAVE_VFS_ITERATE_SHARED */ /* ARGSUSED */ static int zpl_shares_getattr_impl(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { struct inode *ip = path->dentry->d_inode; zfsvfs_t *zfsvfs = ITOZSB(ip); znode_t *dzp; int error; ZFS_ENTER(zfsvfs); if (zfsvfs->z_shares_dir == 0) { generic_fillattr(path->dentry->d_inode, stat); stat->nlink = stat->size = 2; stat->atime = current_time(ip); ZFS_EXIT(zfsvfs); return (0); } error = -zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp); if (error == 0) { error = -zfs_getattr_fast(ZTOI(dzp), stat); iput(ZTOI(dzp)); } ZFS_EXIT(zfsvfs); ASSERT3S(error, <=, 0); return (error); } ZPL_GETATTR_WRAPPER(zpl_shares_getattr); /* * The '.zfs/shares' directory file operations. */ const struct file_operations zpl_fops_shares = { .open = zpl_common_open, .llseek = generic_file_llseek, .read = generic_read_dir, #ifdef HAVE_VFS_ITERATE_SHARED .iterate_shared = zpl_shares_iterate, #elif defined(HAVE_VFS_ITERATE) .iterate = zpl_shares_iterate, #else .readdir = zpl_shares_readdir, #endif }; /* * The '.zfs/shares' directory inode operations. */ const struct inode_operations zpl_ops_shares = { .lookup = zpl_shares_lookup, .getattr = zpl_shares_getattr, };