From: "J. Bruce Fields" <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> To: Al Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org> Cc: linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Dave Chinner <david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org>, "J. Bruce Fields" <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Tyler Hicks <tyhicks-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>, Dustin Kirkland <dustin.kirkland-Bv2LyzZ6GzxBDgjK7y7TUQ@public.gmane.org> Subject: [PATCH 11/16] locks: break delegations on link Date: Wed, 17 Jul 2013 16:50:12 -0400 [thread overview] Message-ID: <1374094217-31493-13-git-send-email-bfields@redhat.com> (raw) In-Reply-To: <1374094217-31493-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> From: "J. Bruce Fields" <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Cc: Tyler Hicks <tyhicks-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org> Cc: Dustin Kirkland <dustin.kirkland-Bv2LyzZ6GzxBDgjK7y7TUQ@public.gmane.org> Acked-by: Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Signed-off-by: J. Bruce Fields <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> --- fs/ecryptfs/inode.c | 2 +- fs/namei.c | 36 ++++++++++++++++++++++++++++++++---- fs/nfsd/vfs.c | 2 +- include/linux/fs.h | 2 +- 4 files changed, 35 insertions(+), 7 deletions(-) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 0b8b632..cb3ac33 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -475,7 +475,7 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir, dget(lower_new_dentry); lower_dir_dentry = lock_parent(lower_new_dentry); rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode, - lower_new_dentry); + lower_new_dentry, NULL); if (rc || !lower_new_dentry->d_inode) goto out_lock; rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb); diff --git a/fs/namei.c b/fs/namei.c index 0554c9a..bd1f78e 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3631,7 +3631,26 @@ SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newn return sys_symlinkat(oldname, AT_FDCWD, newname); } -int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) +/** + * vfs_link - create a new link + * @old_dentry: object to be linked + * @dir: new parent + * @new_dentry: where to create the new link + * @delegated_inode: returns inode needing a delegation break + * + * The caller must hold dir->i_mutex + * + * If vfs_link discovers a delegation on the to-be-linked file in need + * of breaking, it will return -EWOULDBLOCK and return a reference to the + * inode in delegated_inode. The caller should then break the delegation + * and retry. Because breaking a delegation may take a long time, the + * caller should drop the i_mutex before doing so. + * + * Alternatively, a caller may pass NULL for delegated_inode. This may + * be appropriate for callers that expect the underlying filesystem not + * to be NFS exported. + */ +int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry, struct inode **delegated_inode) { struct inode *inode = old_dentry->d_inode; unsigned max_links = dir->i_sb->s_max_links; @@ -3667,8 +3686,11 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de error = -ENOENT; else if (max_links && inode->i_nlink >= max_links) error = -EMLINK; - else - error = dir->i_op->link(old_dentry, dir, new_dentry); + else { + error = try_break_deleg(inode, delegated_inode); + if (!error) + error = dir->i_op->link(old_dentry, dir, new_dentry); + } if (!error && (inode->i_state & I_LINKABLE)) { spin_lock(&inode->i_lock); @@ -3695,6 +3717,7 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, { struct dentry *new_dentry; struct path old_path, new_path; + struct inode *delegated_inode = NULL; int how = 0; int error; @@ -3733,9 +3756,14 @@ retry: error = security_path_link(old_path.dentry, &new_path, new_dentry); if (error) goto out_dput; - error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry); + error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry, &delegated_inode); out_dput: done_path_create(&new_path, new_dentry); + if (delegated_inode) { + error = break_deleg_wait(&delegated_inode); + if (!error) + goto retry; + } if (retry_estale(error, how)) { how |= LOOKUP_REVAL; goto retry; diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index fbf22d2..5479fff 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1736,7 +1736,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, err = nfserrno(host_err); goto out_dput; } - host_err = vfs_link(dold, dirp, dnew); + host_err = vfs_link(dold, dirp, dnew, NULL); if (!host_err) { err = nfserrno(commit_metadata(ffhp)); if (!err) diff --git a/include/linux/fs.h b/include/linux/fs.h index 74aa0c7..a2403f9 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1467,7 +1467,7 @@ extern int vfs_create(struct inode *, struct dentry *, umode_t, bool); extern int vfs_mkdir(struct inode *, struct dentry *, umode_t); extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t); extern int vfs_symlink(struct inode *, struct dentry *, const char *); -extern int vfs_link(struct dentry *, struct inode *, struct dentry *); +extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **); extern int vfs_rmdir(struct inode *, struct dentry *); extern int vfs_unlink(struct inode *, struct dentry *, struct inode **); extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html
WARNING: multiple messages have this Message-ID (diff)
From: "J. Bruce Fields" <bfields@redhat.com> To: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, jlayton@redhat.com, Dave Chinner <david@fromorbit.com>, "J. Bruce Fields" <bfields@redhat.com>, Tyler Hicks <tyhicks@canonical.com>, Dustin Kirkland <dustin.kirkland@gazzang.com> Subject: [PATCH 11/16] locks: break delegations on link Date: Wed, 17 Jul 2013 16:50:12 -0400 [thread overview] Message-ID: <1374094217-31493-13-git-send-email-bfields@redhat.com> (raw) In-Reply-To: <1374094217-31493-1-git-send-email-bfields@redhat.com> From: "J. Bruce Fields" <bfields@redhat.com> Cc: Tyler Hicks <tyhicks@canonical.com> Cc: Dustin Kirkland <dustin.kirkland@gazzang.com> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> --- fs/ecryptfs/inode.c | 2 +- fs/namei.c | 36 ++++++++++++++++++++++++++++++++---- fs/nfsd/vfs.c | 2 +- include/linux/fs.h | 2 +- 4 files changed, 35 insertions(+), 7 deletions(-) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 0b8b632..cb3ac33 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -475,7 +475,7 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir, dget(lower_new_dentry); lower_dir_dentry = lock_parent(lower_new_dentry); rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode, - lower_new_dentry); + lower_new_dentry, NULL); if (rc || !lower_new_dentry->d_inode) goto out_lock; rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb); diff --git a/fs/namei.c b/fs/namei.c index 0554c9a..bd1f78e 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3631,7 +3631,26 @@ SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newn return sys_symlinkat(oldname, AT_FDCWD, newname); } -int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) +/** + * vfs_link - create a new link + * @old_dentry: object to be linked + * @dir: new parent + * @new_dentry: where to create the new link + * @delegated_inode: returns inode needing a delegation break + * + * The caller must hold dir->i_mutex + * + * If vfs_link discovers a delegation on the to-be-linked file in need + * of breaking, it will return -EWOULDBLOCK and return a reference to the + * inode in delegated_inode. The caller should then break the delegation + * and retry. Because breaking a delegation may take a long time, the + * caller should drop the i_mutex before doing so. + * + * Alternatively, a caller may pass NULL for delegated_inode. This may + * be appropriate for callers that expect the underlying filesystem not + * to be NFS exported. + */ +int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry, struct inode **delegated_inode) { struct inode *inode = old_dentry->d_inode; unsigned max_links = dir->i_sb->s_max_links; @@ -3667,8 +3686,11 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de error = -ENOENT; else if (max_links && inode->i_nlink >= max_links) error = -EMLINK; - else - error = dir->i_op->link(old_dentry, dir, new_dentry); + else { + error = try_break_deleg(inode, delegated_inode); + if (!error) + error = dir->i_op->link(old_dentry, dir, new_dentry); + } if (!error && (inode->i_state & I_LINKABLE)) { spin_lock(&inode->i_lock); @@ -3695,6 +3717,7 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, { struct dentry *new_dentry; struct path old_path, new_path; + struct inode *delegated_inode = NULL; int how = 0; int error; @@ -3733,9 +3756,14 @@ retry: error = security_path_link(old_path.dentry, &new_path, new_dentry); if (error) goto out_dput; - error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry); + error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry, &delegated_inode); out_dput: done_path_create(&new_path, new_dentry); + if (delegated_inode) { + error = break_deleg_wait(&delegated_inode); + if (!error) + goto retry; + } if (retry_estale(error, how)) { how |= LOOKUP_REVAL; goto retry; diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index fbf22d2..5479fff 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1736,7 +1736,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, err = nfserrno(host_err); goto out_dput; } - host_err = vfs_link(dold, dirp, dnew); + host_err = vfs_link(dold, dirp, dnew, NULL); if (!host_err) { err = nfserrno(commit_metadata(ffhp)); if (!err) diff --git a/include/linux/fs.h b/include/linux/fs.h index 74aa0c7..a2403f9 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1467,7 +1467,7 @@ extern int vfs_create(struct inode *, struct dentry *, umode_t, bool); extern int vfs_mkdir(struct inode *, struct dentry *, umode_t); extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t); extern int vfs_symlink(struct inode *, struct dentry *, const char *); -extern int vfs_link(struct dentry *, struct inode *, struct dentry *); +extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **); extern int vfs_rmdir(struct inode *, struct dentry *); extern int vfs_unlink(struct inode *, struct dentry *, struct inode **); extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **); -- 1.7.9.5
next prev parent reply other threads:[~2013-07-17 20:50 UTC|newest] Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-07-17 20:50 [PATCH 00/16] Implement NFSv4 delegations, take 9 J. Bruce Fields 2013-07-17 20:50 ` [PATCH] nfsd4: fix minorversion support interface J. Bruce Fields 2013-07-17 21:08 ` J. Bruce Fields 2013-07-17 20:50 ` [PATCH 02/16] vfs: don't use PARENT/CHILD lock classes for non-directories J. Bruce Fields 2013-07-17 20:50 ` [PATCH 03/16] vfs: rename I_MUTEX_QUOTA now that it's not used for quotas J. Bruce Fields 2013-07-17 20:50 ` [PATCH 04/16] vfs: take i_mutex on renamed file J. Bruce Fields 2013-07-17 20:50 ` [PATCH 08/16] locks: break delegations on unlink J. Bruce Fields 2013-07-17 20:50 ` [PATCH 10/16] locks: break delegations on rename J. Bruce Fields 2013-07-17 20:50 ` [PATCH 13/16] nfsd4: minor nfs4_setlease cleanup J. Bruce Fields 2013-07-26 10:53 ` Jeff Layton [not found] ` <1374094217-31493-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 2013-07-17 20:50 ` [PATCH 01/16] vfs: pull ext4's double-i_mutex-locking into common code J. Bruce Fields 2013-07-17 20:50 ` J. Bruce Fields 2013-07-17 20:50 ` [PATCH 05/16] locks: introduce new FL_DELEG lock flag J. Bruce Fields 2013-07-17 20:50 ` J. Bruce Fields 2013-07-17 20:50 ` [PATCH 06/16] locks: implement delegations J. Bruce Fields 2013-07-17 20:50 ` J. Bruce Fields 2013-07-17 20:50 ` [PATCH 07/16] namei: minor vfs_unlink cleanup J. Bruce Fields 2013-07-17 20:50 ` J. Bruce Fields 2013-07-17 20:50 ` [PATCH 09/16] locks: helper functions for delegation breaking J. Bruce Fields 2013-07-17 20:50 ` J. Bruce Fields [not found] ` <1374094217-31493-11-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 2013-07-26 10:50 ` Jeff Layton 2013-07-26 10:50 ` Jeff Layton 2013-07-17 20:50 ` J. Bruce Fields [this message] 2013-07-17 20:50 ` [PATCH 11/16] locks: break delegations on link J. Bruce Fields 2013-07-17 20:50 ` [PATCH 12/16] locks: break delegations on any attribute modification J. Bruce Fields 2013-07-17 20:50 ` J. Bruce Fields [not found] ` <1374094217-31493-14-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 2013-07-26 10:50 ` Jeff Layton 2013-07-26 10:50 ` Jeff Layton 2013-07-17 20:50 ` [PATCH 14/16] nfsd4: delay setting current_fh in open J. Bruce Fields 2013-07-17 20:50 ` J. Bruce Fields [not found] ` <1374094217-31493-16-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 2013-07-26 11:11 ` Jeff Layton 2013-07-26 11:11 ` Jeff Layton 2013-07-26 16:04 ` J. Bruce Fields 2013-07-17 20:50 ` [PATCH 15/16] nfsd4: close open-deleg/unlink/rename race J. Bruce Fields 2013-07-17 20:50 ` J. Bruce Fields 2013-07-26 11:23 ` Jeff Layton [not found] ` <20130726072326.56113a2c-4QP7MXygkU+dMjc06nkz3ljfA9RmPOcC@public.gmane.org> 2013-07-26 16:04 ` J. Bruce Fields 2013-07-26 16:04 ` J. Bruce Fields 2013-07-26 21:14 ` J. Bruce Fields 2013-07-17 20:50 ` [PATCH 16/16] nfsd4: break only delegations when appropriate J. Bruce Fields [not found] ` <1374094217-31493-18-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 2013-07-26 11:24 ` Jeff Layton 2013-07-26 11:24 ` Jeff Layton 2013-07-17 21:09 ` [PATCH 00/16] Implement NFSv4 delegations, take 9 J. Bruce Fields
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