On Wed, 2021-07-07 at 11:37 +0800, Xiubo Li wrote: > On 6/25/21 9:58 PM, Jeff Layton wrote: > > When creating a new inode, we need to determine the crypto context > > before we can transmit the RPC. The fscrypt API has a routine for getting > > a crypto context before a create occurs, but it requires an inode. > > > > Change the ceph code to preallocate an inode in advance of a create of > > any sort (open(), mknod(), symlink(), etc). Move the existing code that > > generates the ACL and SELinux blobs into this routine since that's > > mostly common across all the different codepaths. > > > > In most cases, we just want to allow ceph_fill_trace to use that inode > > after the reply comes in, so add a new field to the MDS request for it > > (r_new_inode). > > > > The async create codepath is a bit different though. In that case, we > > want to hash the inode in advance of the RPC so that it can be used > > before the reply comes in. If the call subsequently fails with > > -EJUKEBOX, then just put the references and clean up the as_ctx. Note > > that with this change, we now need to regenerate the as_ctx when this > > occurs, but it's quite rare for it to happen. > > > > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> > > --- > > fs/ceph/dir.c | 70 ++++++++++++++++++++----------------- > > fs/ceph/file.c | 62 ++++++++++++++++++++------------- > > fs/ceph/inode.c | 82 ++++++++++++++++++++++++++++++++++++++++---- > > fs/ceph/mds_client.c | 3 +- > > fs/ceph/mds_client.h | 1 + > > fs/ceph/super.h | 7 +++- > > 6 files changed, 160 insertions(+), 65 deletions(-) > > > [...] > > > diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c > > index eb562e259347..f62785e4dbcb 100644 > > --- a/fs/ceph/inode.c > > +++ b/fs/ceph/inode.c > > @@ -52,17 +52,85 @@ static int ceph_set_ino_cb(struct inode *inode, void *data) > > return 0; > > } > > > > -struct inode *ceph_get_inode(struct super_block *sb, struct ceph_vino vino) > > +/** > > + * ceph_new_inode - allocate a new inode in advance of an expected create > > + * @dir: parent directory for new inode > > + * @dentry: dentry that may eventually point to new inode > > + * @mode: mode of new inode > > + * @as_ctx: pointer to inherited security context > > + * > > + * Allocate a new inode in advance of an operation to create a new inode. > > + * This allocates the inode and sets up the acl_sec_ctx with appropriate > > + * info for the new inode. > > + * > > + * Returns a pointer to the new inode or an ERR_PTR. > > + */ > > +struct inode *ceph_new_inode(struct inode *dir, struct dentry *dentry, > > + umode_t *mode, struct ceph_acl_sec_ctx *as_ctx) > > +{ > > + int err; > > + struct inode *inode; > > + > > + inode = new_inode_pseudo(dir->i_sb); > > + if (!inode) > > + return ERR_PTR(-ENOMEM); > > + > > + if (!S_ISLNK(*mode)) { > > + err = ceph_pre_init_acls(dir, mode, as_ctx); > > + if (err < 0) > > + goto out_err; > > + } > > + > > + err = ceph_security_init_secctx(dentry, *mode, as_ctx); > > + if (err < 0) > > + goto out_err; > > + > > + inode->i_state = 0; > > + inode->i_mode = *mode; > > + return inode; > > +out_err: > > + iput(inode); > > + return ERR_PTR(err); > > +} > > + > > +void ceph_as_ctx_to_req(struct ceph_mds_request *req, struct ceph_acl_sec_ctx *as_ctx) > > +{ > > + if (as_ctx->pagelist) { > > + req->r_pagelist = as_ctx->pagelist; > > + as_ctx->pagelist = NULL; > > + } > > +} > > + > > +/** > > + * ceph_get_inode - find or create/hash a new inode > > + * @sb: superblock to search and allocate in > > + * @vino: vino to search for > > + * @newino: optional new inode to insert if one isn't found (may be NULL) > > + * > > + * Search for or insert a new inode into the hash for the given vino, and return a > > + * reference to it. If new is non-NULL, its reference is consumed. > > + */ > > +struct inode *ceph_get_inode(struct super_block *sb, struct ceph_vino vino, struct inode *newino) > > { > > struct inode *inode; > > > > if (ceph_vino_is_reserved(vino)) > > return ERR_PTR(-EREMOTEIO); > > > > - inode = iget5_locked(sb, (unsigned long)vino.ino, ceph_ino_compare, > > - ceph_set_ino_cb, &vino); > > - if (!inode) > > + if (newino) { > > + inode = inode_insert5(newino, (unsigned long)vino.ino, ceph_ino_compare, > > + ceph_set_ino_cb, &vino); > > + if (inode != newino) > > + iput(newino); > > + } else { > > + inode = iget5_locked(sb, (unsigned long)vino.ino, ceph_ino_compare, > > + ceph_set_ino_cb, &vino); > > + } > > + > > + if (!inode) { > > + dout("No inode found for %llx.%llx\n", vino.ino, vino.snap); > > return ERR_PTR(-ENOMEM); > > + } > > > > dout("get_inode on %llu=%llx.%llx got %p new %d\n", ceph_present_inode(inode), > > ceph_vinop(inode), inode, !!(inode->i_state & I_NEW)); > > @@ -78,7 +146,7 @@ struct inode *ceph_get_snapdir(struct inode *parent) > > .ino = ceph_ino(parent), > > .snap = CEPH_SNAPDIR, > > }; > > - struct inode *inode = ceph_get_inode(parent->i_sb, vino); > > + struct inode *inode = ceph_get_inode(parent->i_sb, vino, NULL); > > struct ceph_inode_info *ci = ceph_inode(inode); > > > > if (IS_ERR(inode)) > > Should we always check this just before using it before 'struct > ceph_inode_info *ci = ceph_inode(inode);' ? > > But it seems the 'ceph_inode()' won't introduce any issue here. > > Thanks, > Yeah, it's just doing pointer math. If it turns out to be an error, it'll exit before it ever dereferences "ci". > > @@ -1546,7 +1614,7 @@ static int readdir_prepopulate_inodes_only(struct ceph_mds_request *req, > > vino.ino = le64_to_cpu(rde->inode.in->ino); > > vino.snap = le64_to_cpu(rde->inode.in->snapid); > > > > - in = ceph_get_inode(req->r_dentry->d_sb, vino); > > + in = ceph_get_inode(req->r_dentry->d_sb, vino, NULL); > > if (IS_ERR(in)) { > > err = PTR_ERR(in); > > dout("new_inode badness got %d\n", err); > > @@ -1748,7 +1816,7 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req, > > if (d_really_is_positive(dn)) { > > in = d_inode(dn); > > } else { > > - in = ceph_get_inode(parent->d_sb, tvino); > > + in = ceph_get_inode(parent->d_sb, tvino, NULL); > > if (IS_ERR(in)) { > > dout("new_inode badness\n"); > > d_drop(dn); > [...] > -- Jeff Layton <jlayton@xxxxxxxxxx>
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