diff options
Diffstat (limited to 'module')
| -rw-r--r-- | module/zfs/zpl_ctldir.c | 124 |
1 files changed, 66 insertions, 58 deletions
diff --git a/module/zfs/zpl_ctldir.c b/module/zfs/zpl_ctldir.c index 7dfaf6ebc..2e5209f8c 100644 --- a/module/zfs/zpl_ctldir.c +++ b/module/zfs/zpl_ctldir.c @@ -183,6 +183,66 @@ const struct inode_operations zpl_ops_root = { .getattr = zpl_root_getattr, }; +#ifdef HAVE_AUTOMOUNT +static struct vfsmount * +zpl_snapdir_automount(struct path *path) +{ + struct dentry *dentry = path->dentry; + int error; + + /* + * We must briefly disable automounts for this dentry because the + * user space mount utility will trigger another lookup on this + * directory. That will result in zpl_snapdir_automount() being + * called repeatedly. The DCACHE_NEED_AUTOMOUNT flag can be + * safely reset once the mount completes. + */ + dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT; + error = -zfsctl_mount_snapshot(path, 0); + dentry->d_flags |= DCACHE_NEED_AUTOMOUNT; + 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 */ + +/* + * Revalidate any dentry in the snapshot directory on lookup, since a snapshot + * having the same name have been created or destroyed since it was cached. + */ +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 0; +} + +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, @@ -194,7 +254,7 @@ zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry, { cred_t *cr = CRED(); - struct inode *ip; + struct inode *ip = NULL; int error; crhold(cr); @@ -203,24 +263,11 @@ zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry, ASSERT3S(error, <=, 0); crfree(cr); - if (error) { - if (error == -ENOENT) - return d_splice_alias(NULL, dentry); - else - return ERR_PTR(error); - } + if (error && error != -ENOENT) + return ERR_PTR(error); - /* - * 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 - dentry->d_op = &zpl_dops_snapdirs; -#endif /* HAVE_AUTOMOUNT */ + ASSERT(error == 0 || ip == NULL); + d_set_d_op(dentry, &zpl_dops_snapdirs); return d_splice_alias(ip, dentry); } @@ -323,9 +370,7 @@ zpl_snapdir_mkdir(struct inode *dip, struct dentry *dentry, zpl_umode_t mode) error = -zfsctl_snapdir_mkdir(dip, dname(dentry), vap, &ip, cr, 0); if (error == 0) { -#ifdef HAVE_AUTOMOUNT - dentry->d_op = &zpl_dops_snapdirs; -#endif /* HAVE_AUTOMOUNT */ + d_set_d_op(dentry, &zpl_dops_snapdirs); d_instantiate(dentry, ip); } @@ -336,37 +381,6 @@ zpl_snapdir_mkdir(struct inode *dip, struct dentry *dentry, zpl_umode_t mode) return (error); } -#ifdef HAVE_AUTOMOUNT -static struct vfsmount * -zpl_snapdir_automount(struct path *path) -{ - struct dentry *dentry = path->dentry; - int error; - - /* - * We must briefly disable automounts for this dentry because the - * user space mount utility will trigger another lookup on this - * directory. That will result in zpl_snapdir_automount() being - * called repeatedly. The DCACHE_NEED_AUTOMOUNT flag can be - * safely reset once the mount completes. - */ - dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT; - error = -zfsctl_mount_snapshot(path, 0); - dentry->d_flags |= DCACHE_NEED_AUTOMOUNT; - 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 */ - /* * Get snapshot directory attributes. */ @@ -413,12 +427,6 @@ const struct inode_operations zpl_ops_snapdir = { .mkdir = zpl_snapdir_mkdir, }; -#ifdef HAVE_AUTOMOUNT -const struct dentry_operations zpl_dops_snapdirs = { - .d_automount = zpl_snapdir_automount, -}; -#endif /* HAVE_AUTOMOUNT */ - static struct dentry * #ifdef HAVE_LOOKUP_NAMEIDATA zpl_shares_lookup(struct inode *dip, struct dentry *dentry, |