From 5ef50c3bec20060bc114f62d6503c5d86d70bdd7 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 31 Jul 2012 11:27:36 -0700 Subject: ceph: simplify+fix atomic_open The initial ->atomic_open op was carried over from the old intent code, which was incomplete and didn't really work. Replace it with a fresh method. In particular: * always attempt to do an atomic open+lookup, both for the create case and for lookups of existing files. * fix symlink handling by returning 1 to the VFS so that we can follow the link to its destination. This fixes a longstanding ceph bug (#2392). Signed-off-by: Sage Weil --- fs/ceph/dir.c | 38 ----------------------------------- fs/ceph/file.c | 62 ++++++++++++++++++++++++++++++++++----------------------- fs/ceph/super.h | 6 +++--- 3 files changed, 40 insertions(+), 66 deletions(-) (limited to 'fs') diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index f391f1e75414..e5b77319c97b 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -633,44 +633,6 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry, return dentry; } -int ceph_atomic_open(struct inode *dir, struct dentry *dentry, - struct file *file, unsigned flags, umode_t mode, - int *opened) -{ - int err; - struct dentry *res = NULL; - - if (!(flags & O_CREAT)) { - if (dentry->d_name.len > NAME_MAX) - return -ENAMETOOLONG; - - err = ceph_init_dentry(dentry); - if (err < 0) - return err; - - return ceph_lookup_open(dir, dentry, file, flags, mode, opened); - } - - if (d_unhashed(dentry)) { - res = ceph_lookup(dir, dentry, 0); - if (IS_ERR(res)) - return PTR_ERR(res); - - if (res) - dentry = res; - } - - /* We don't deal with positive dentries here */ - if (dentry->d_inode) - return finish_no_open(file, res); - - *opened |= FILE_CREATED; - err = ceph_lookup_open(dir, dentry, file, flags, mode, opened); - dput(res); - - return err; -} - /* * If we do a create but get no trace back from the MDS, follow up with * a lookup (the VFS expects us to link up the provided dentry). diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 1b81d6c31878..ecebbc09bfc7 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include @@ -106,9 +107,6 @@ static int ceph_init_file(struct inode *inode, struct file *file, int fmode) } /* - * If the filp already has private_data, that means the file was - * already opened by intent during lookup, and we do nothing. - * * If we already have the requisite capabilities, we can satisfy * the open request locally (no need to request new caps from the * MDS). We do, however, need to inform the MDS (asynchronously) @@ -207,24 +205,29 @@ out: /* - * Do a lookup + open with a single request. - * - * If this succeeds, but some subsequent check in the vfs - * may_open() fails, the struct *file gets cleaned up (i.e. - * ceph_release gets called). So fear not! + * Do a lookup + open with a single request. If we get a non-existent + * file or symlink, return 1 so the VFS can retry. */ -int ceph_lookup_open(struct inode *dir, struct dentry *dentry, +int ceph_atomic_open(struct inode *dir, struct dentry *dentry, struct file *file, unsigned flags, umode_t mode, int *opened) { struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb); struct ceph_mds_client *mdsc = fsc->mdsc; struct ceph_mds_request *req; - struct dentry *ret; + struct dentry *dn; int err; - dout("ceph_lookup_open dentry %p '%.*s' flags %d mode 0%o\n", - dentry, dentry->d_name.len, dentry->d_name.name, flags, mode); + dout("atomic_open %p dentry %p '%.*s' %s flags %d mode 0%o\n", + dir, dentry, dentry->d_name.len, dentry->d_name.name, + d_unhashed(dentry) ? "unhashed" : "hashed", flags, mode); + + if (dentry->d_name.len > NAME_MAX) + return -ENAMETOOLONG; + + err = ceph_init_dentry(dentry); + if (err < 0) + return err; /* do the open */ req = prepare_open_request(dir->i_sb, flags, mode); @@ -241,22 +244,31 @@ int ceph_lookup_open(struct inode *dir, struct dentry *dentry, (flags & (O_CREAT|O_TRUNC)) ? dir : NULL, req); err = ceph_handle_snapdir(req, dentry, err); - if (err) - goto out; - if ((flags & O_CREAT) && !req->r_reply_info.head->is_dentry) + if (err == 0 && (flags & O_CREAT) && !req->r_reply_info.head->is_dentry) err = ceph_handle_notrace_create(dir, dentry); - if (err) - goto out; - err = finish_open(file, req->r_dentry, ceph_open, opened); -out: - ret = ceph_finish_lookup(req, dentry, err); - ceph_mdsc_put_request(req); - dout("ceph_lookup_open result=%p\n", ret); - if (IS_ERR(ret)) - return PTR_ERR(ret); + if (d_unhashed(dentry)) { + dn = ceph_finish_lookup(req, dentry, err); + if (IS_ERR(dn)) + err = PTR_ERR(dn); + } else { + /* we were given a hashed negative dentry */ + dn = NULL; + } + if (err) + goto out_err; + if (dn || dentry->d_inode == NULL || S_ISLNK(dentry->d_inode->i_mode)) { + /* make vfs retry on splice, ENOENT, or symlink */ + dout("atomic_open finish_no_open on dn %p\n", dn); + err = finish_no_open(file, dn); + } else { + dout("atomic_open finish_open on dn %p\n", dn); + err = finish_open(file, dentry, ceph_open, opened); + } - dput(ret); +out_err: + ceph_mdsc_put_request(req); + dout("atomic_open result=%d\n", err); return err; } diff --git a/fs/ceph/super.h b/fs/ceph/super.h index ebc95cc652be..66ebe720e40d 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -806,9 +806,9 @@ extern int ceph_copy_from_page_vector(struct page **pages, loff_t off, size_t len); extern struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags); extern int ceph_open(struct inode *inode, struct file *file); -extern int ceph_lookup_open(struct inode *dir, struct dentry *dentry, - struct file *od, unsigned flags, - umode_t mode, int *opened); +extern int ceph_atomic_open(struct inode *dir, struct dentry *dentry, + struct file *file, unsigned flags, umode_t mode, + int *opened); extern int ceph_release(struct inode *inode, struct file *filp); /* dir.c */ -- cgit v1.2.3-59-g8ed1b