| Message ID | 1374094217-31493-14-git-send-email-bfields@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 17 Jul 2013 16:50:13 -0400 "J. Bruce Fields" <bfields@redhat.com> wrote: > From: "J. Bruce Fields" <bfields@redhat.com> > > NFSv4 uses leases to guarantee that clients can cache metadata as well > as data. > > Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> > Cc: David Howells <dhowells@redhat.com> > Cc: Tyler Hicks <tyhicks@canonical.com> > Cc: Dustin Kirkland <dustin.kirkland@gazzang.com> > Signed-off-by: J. Bruce Fields <bfields@redhat.com> > --- > drivers/base/devtmpfs.c | 4 ++-- > fs/attr.c | 25 ++++++++++++++++++++++++- > fs/cachefiles/interface.c | 4 ++-- > fs/ecryptfs/inode.c | 2 +- > fs/hpfs/namei.c | 2 +- > fs/inode.c | 6 +++++- > fs/nfsd/vfs.c | 8 ++++++-- > fs/open.c | 22 ++++++++++++++++++---- > fs/utimes.c | 9 ++++++++- > include/linux/fs.h | 2 +- > 10 files changed, 68 insertions(+), 16 deletions(-) > > diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c > index 1b8490e..0f38201 100644 > --- a/drivers/base/devtmpfs.c > +++ b/drivers/base/devtmpfs.c > @@ -216,7 +216,7 @@ static int handle_create(const char *nodename, umode_t mode, kuid_t uid, > newattrs.ia_gid = gid; > newattrs.ia_valid = ATTR_MODE|ATTR_UID|ATTR_GID; > mutex_lock(&dentry->d_inode->i_mutex); > - notify_change(dentry, &newattrs); > + notify_change(dentry, &newattrs, NULL); > mutex_unlock(&dentry->d_inode->i_mutex); > > /* mark as kernel-created inode */ > @@ -322,7 +322,7 @@ static int handle_remove(const char *nodename, struct device *dev) > newattrs.ia_valid = > ATTR_UID|ATTR_GID|ATTR_MODE; > mutex_lock(&dentry->d_inode->i_mutex); > - notify_change(dentry, &newattrs); > + notify_change(dentry, &newattrs, NULL); > mutex_unlock(&dentry->d_inode->i_mutex); > err = vfs_unlink(parent.dentry->d_inode, dentry, NULL); > if (!err || err == -ENOENT) > diff --git a/fs/attr.c b/fs/attr.c > index 1449adb..267968d 100644 > --- a/fs/attr.c > +++ b/fs/attr.c > @@ -167,7 +167,27 @@ void setattr_copy(struct inode *inode, const struct iattr *attr) > } > EXPORT_SYMBOL(setattr_copy); > > -int notify_change(struct dentry * dentry, struct iattr * attr) > +/** > + * notify_change - modify attributes of a filesytem object > + * @dentry: object affected > + * @iattr: new attributes > + * @delegated_inode: returns inode, if the inode is delegated > + * > + * The caller must hold the i_mutex on the affected object. > + * > + * If notify_change discovers a delegation 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. Also, passing NULL is fine for callers holding > + * the file open for write, as there can be no conflicting delegation in > + * that case. > + */ > +int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **delegated_inode) > { > struct inode *inode = dentry->d_inode; > umode_t mode = inode->i_mode; > @@ -243,6 +263,9 @@ int notify_change(struct dentry * dentry, struct iattr * attr) > error = security_inode_setattr(dentry, attr); > if (error) > return error; > + error = try_break_deleg(inode, delegated_inode); > + if (error) > + return error; > > if (inode->i_op->setattr) > error = inode->i_op->setattr(dentry, attr); > diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c > index d4c1206..ccc01f1 100644 > --- a/fs/cachefiles/interface.c > +++ b/fs/cachefiles/interface.c > @@ -424,14 +424,14 @@ static int cachefiles_attr_changed(struct fscache_object *_object) > _debug("discard tail %llx", oi_size); > newattrs.ia_valid = ATTR_SIZE; > newattrs.ia_size = oi_size & PAGE_MASK; > - ret = notify_change(object->backer, &newattrs); > + ret = notify_change(object->backer, &newattrs, NULL); > if (ret < 0) > goto truncate_failed; > } > > newattrs.ia_valid = ATTR_SIZE; > newattrs.ia_size = ni_size; > - ret = notify_change(object->backer, &newattrs); > + ret = notify_change(object->backer, &newattrs, NULL); > > truncate_failed: > mutex_unlock(&object->backer->d_inode->i_mutex); > diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c > index cb3ac33..7b19ebb 100644 > --- a/fs/ecryptfs/inode.c > +++ b/fs/ecryptfs/inode.c > @@ -992,7 +992,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) > lower_ia.ia_valid &= ~ATTR_MODE; > > mutex_lock(&lower_dentry->d_inode->i_mutex); > - rc = notify_change(lower_dentry, &lower_ia); > + rc = notify_change(lower_dentry, &lower_ia, NULL); > mutex_unlock(&lower_dentry->d_inode->i_mutex); > out: > fsstack_copy_attr_all(inode, lower_inode); > diff --git a/fs/hpfs/namei.c b/fs/hpfs/namei.c > index 345713d..1b39afd 100644 > --- a/fs/hpfs/namei.c > +++ b/fs/hpfs/namei.c > @@ -407,7 +407,7 @@ again: > /*printk("HPFS: truncating file before delete.\n");*/ > newattrs.ia_size = 0; > newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME; > - err = notify_change(dentry, &newattrs); > + err = notify_change(dentry, &newattrs, NULL); > put_write_access(inode); > if (!err) > goto again; > diff --git a/fs/inode.c b/fs/inode.c > index 4178e91..82a5a30 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -1642,7 +1642,11 @@ static int __remove_suid(struct dentry *dentry, int kill) > struct iattr newattrs; > > newattrs.ia_valid = ATTR_FORCE | kill; > - return notify_change(dentry, &newattrs); > + /* > + * Note we call this on write, so notify_change will not > + * encounter any conflicting delegations: > + */ > + return notify_change(dentry, &newattrs, NULL); > } > > int file_remove_suid(struct file *file) > diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c > index 5479fff..2586f6d 100644 > --- a/fs/nfsd/vfs.c > +++ b/fs/nfsd/vfs.c > @@ -427,7 +427,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, > goto out_nfserr; > fh_lock(fhp); > > - host_err = notify_change(dentry, iap); > + host_err = notify_change(dentry, iap, NULL); > err = nfserrno(host_err); > fh_unlock(fhp); > } > @@ -987,7 +987,11 @@ static void kill_suid(struct dentry *dentry) > ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; > > mutex_lock(&dentry->d_inode->i_mutex); > - notify_change(dentry, &ia); > + /* > + * Note we call this on write, so notify_change will not > + * encounter any conflicting delegations: > + */ > + notify_change(dentry, &ia, NULL); > mutex_unlock(&dentry->d_inode->i_mutex); > } > > diff --git a/fs/open.c b/fs/open.c > index 9156cb0..68e50fd 100644 > --- a/fs/open.c > +++ b/fs/open.c > @@ -57,7 +57,8 @@ int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, > newattrs.ia_valid |= ret | ATTR_FORCE; > > mutex_lock(&dentry->d_inode->i_mutex); > - ret = notify_change(dentry, &newattrs); > + /* Note any delegations or leases have already been broken: */ > + ret = notify_change(dentry, &newattrs, NULL); > mutex_unlock(&dentry->d_inode->i_mutex); > return ret; > } > @@ -464,21 +465,28 @@ out: > static int chmod_common(struct path *path, umode_t mode) > { > struct inode *inode = path->dentry->d_inode; > + struct inode *delegated_inode = NULL; > struct iattr newattrs; > int error; > > error = mnt_want_write(path->mnt); > if (error) > return error; > +retry_deleg: > mutex_lock(&inode->i_mutex); > error = security_path_chmod(path, mode); > if (error) > goto out_unlock; > newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); > newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; > - error = notify_change(path->dentry, &newattrs); > + error = notify_change(path->dentry, &newattrs, &delegated_inode); > out_unlock: > mutex_unlock(&inode->i_mutex); > + if (delegated_inode) { > + error = break_deleg_wait(&delegated_inode); > + if (!error) > + goto retry_deleg; > + } > mnt_drop_write(path->mnt); > return error; > } > @@ -523,6 +531,7 @@ SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode) > static int chown_common(struct path *path, uid_t user, gid_t group) > { > struct inode *inode = path->dentry->d_inode; > + struct inode *delegated_inode = NULL; > int error; > struct iattr newattrs; > kuid_t uid; > @@ -547,12 +556,17 @@ static int chown_common(struct path *path, uid_t user, gid_t group) > if (!S_ISDIR(inode->i_mode)) > newattrs.ia_valid |= > ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; > +retry_deleg: > mutex_lock(&inode->i_mutex); > error = security_path_chown(path, uid, gid); > if (!error) > - error = notify_change(path->dentry, &newattrs); > + error = notify_change(path->dentry, &newattrs, &delegated_inode); > mutex_unlock(&inode->i_mutex); > - > + if (delegated_inode) { > + error = break_deleg_wait(&delegated_inode); > + if (!error) > + goto retry_deleg; > + } > return error; > } > > diff --git a/fs/utimes.c b/fs/utimes.c > index f4fb7ec..aa138d6 100644 > --- a/fs/utimes.c > +++ b/fs/utimes.c > @@ -53,6 +53,7 @@ static int utimes_common(struct path *path, struct timespec *times) > int error; > struct iattr newattrs; > struct inode *inode = path->dentry->d_inode; > + struct inode *delegated_inode = NULL; > > error = mnt_want_write(path->mnt); > if (error) > @@ -101,9 +102,15 @@ static int utimes_common(struct path *path, struct timespec *times) > goto mnt_drop_write_and_out; > } > } > +retry_deleg: > mutex_lock(&inode->i_mutex); > - error = notify_change(path->dentry, &newattrs); > + error = notify_change(path->dentry, &newattrs, &delegated_inode); > mutex_unlock(&inode->i_mutex); > + if (delegated_inode) { > + error = break_deleg_wait(&delegated_inode); > + if (!error) > + goto retry_deleg; > + } > > mnt_drop_write_and_out: > mnt_drop_write(path->mnt); > diff --git a/include/linux/fs.h b/include/linux/fs.h > index a2403f9..638cdae 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -2268,7 +2268,7 @@ extern void emergency_remount(void); > #ifdef CONFIG_BLOCK > extern sector_t bmap(struct inode *, sector_t); > #endif > -extern int notify_change(struct dentry *, struct iattr *); > +extern int notify_change(struct dentry *, struct iattr *, struct inode **); > extern int inode_permission(struct inode *, int); > extern int generic_permission(struct inode *, int); > Acked-by: Jeff Layton <jlayton@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index 1b8490e..0f38201 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -216,7 +216,7 @@ static int handle_create(const char *nodename, umode_t mode, kuid_t uid, newattrs.ia_gid = gid; newattrs.ia_valid = ATTR_MODE|ATTR_UID|ATTR_GID; mutex_lock(&dentry->d_inode->i_mutex); - notify_change(dentry, &newattrs); + notify_change(dentry, &newattrs, NULL); mutex_unlock(&dentry->d_inode->i_mutex); /* mark as kernel-created inode */ @@ -322,7 +322,7 @@ static int handle_remove(const char *nodename, struct device *dev) newattrs.ia_valid = ATTR_UID|ATTR_GID|ATTR_MODE; mutex_lock(&dentry->d_inode->i_mutex); - notify_change(dentry, &newattrs); + notify_change(dentry, &newattrs, NULL); mutex_unlock(&dentry->d_inode->i_mutex); err = vfs_unlink(parent.dentry->d_inode, dentry, NULL); if (!err || err == -ENOENT) diff --git a/fs/attr.c b/fs/attr.c index 1449adb..267968d 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -167,7 +167,27 @@ void setattr_copy(struct inode *inode, const struct iattr *attr) } EXPORT_SYMBOL(setattr_copy); -int notify_change(struct dentry * dentry, struct iattr * attr) +/** + * notify_change - modify attributes of a filesytem object + * @dentry: object affected + * @iattr: new attributes + * @delegated_inode: returns inode, if the inode is delegated + * + * The caller must hold the i_mutex on the affected object. + * + * If notify_change discovers a delegation 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. Also, passing NULL is fine for callers holding + * the file open for write, as there can be no conflicting delegation in + * that case. + */ +int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **delegated_inode) { struct inode *inode = dentry->d_inode; umode_t mode = inode->i_mode; @@ -243,6 +263,9 @@ int notify_change(struct dentry * dentry, struct iattr * attr) error = security_inode_setattr(dentry, attr); if (error) return error; + error = try_break_deleg(inode, delegated_inode); + if (error) + return error; if (inode->i_op->setattr) error = inode->i_op->setattr(dentry, attr); diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c index d4c1206..ccc01f1 100644 --- a/fs/cachefiles/interface.c +++ b/fs/cachefiles/interface.c @@ -424,14 +424,14 @@ static int cachefiles_attr_changed(struct fscache_object *_object) _debug("discard tail %llx", oi_size); newattrs.ia_valid = ATTR_SIZE; newattrs.ia_size = oi_size & PAGE_MASK; - ret = notify_change(object->backer, &newattrs); + ret = notify_change(object->backer, &newattrs, NULL); if (ret < 0) goto truncate_failed; } newattrs.ia_valid = ATTR_SIZE; newattrs.ia_size = ni_size; - ret = notify_change(object->backer, &newattrs); + ret = notify_change(object->backer, &newattrs, NULL); truncate_failed: mutex_unlock(&object->backer->d_inode->i_mutex); diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index cb3ac33..7b19ebb 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -992,7 +992,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) lower_ia.ia_valid &= ~ATTR_MODE; mutex_lock(&lower_dentry->d_inode->i_mutex); - rc = notify_change(lower_dentry, &lower_ia); + rc = notify_change(lower_dentry, &lower_ia, NULL); mutex_unlock(&lower_dentry->d_inode->i_mutex); out: fsstack_copy_attr_all(inode, lower_inode); diff --git a/fs/hpfs/namei.c b/fs/hpfs/namei.c index 345713d..1b39afd 100644 --- a/fs/hpfs/namei.c +++ b/fs/hpfs/namei.c @@ -407,7 +407,7 @@ again: /*printk("HPFS: truncating file before delete.\n");*/ newattrs.ia_size = 0; newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME; - err = notify_change(dentry, &newattrs); + err = notify_change(dentry, &newattrs, NULL); put_write_access(inode); if (!err) goto again; diff --git a/fs/inode.c b/fs/inode.c index 4178e91..82a5a30 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1642,7 +1642,11 @@ static int __remove_suid(struct dentry *dentry, int kill) struct iattr newattrs; newattrs.ia_valid = ATTR_FORCE | kill; - return notify_change(dentry, &newattrs); + /* + * Note we call this on write, so notify_change will not + * encounter any conflicting delegations: + */ + return notify_change(dentry, &newattrs, NULL); } int file_remove_suid(struct file *file) diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 5479fff..2586f6d 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -427,7 +427,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, goto out_nfserr; fh_lock(fhp); - host_err = notify_change(dentry, iap); + host_err = notify_change(dentry, iap, NULL); err = nfserrno(host_err); fh_unlock(fhp); } @@ -987,7 +987,11 @@ static void kill_suid(struct dentry *dentry) ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; mutex_lock(&dentry->d_inode->i_mutex); - notify_change(dentry, &ia); + /* + * Note we call this on write, so notify_change will not + * encounter any conflicting delegations: + */ + notify_change(dentry, &ia, NULL); mutex_unlock(&dentry->d_inode->i_mutex); } diff --git a/fs/open.c b/fs/open.c index 9156cb0..68e50fd 100644 --- a/fs/open.c +++ b/fs/open.c @@ -57,7 +57,8 @@ int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, newattrs.ia_valid |= ret | ATTR_FORCE; mutex_lock(&dentry->d_inode->i_mutex); - ret = notify_change(dentry, &newattrs); + /* Note any delegations or leases have already been broken: */ + ret = notify_change(dentry, &newattrs, NULL); mutex_unlock(&dentry->d_inode->i_mutex); return ret; } @@ -464,21 +465,28 @@ out: static int chmod_common(struct path *path, umode_t mode) { struct inode *inode = path->dentry->d_inode; + struct inode *delegated_inode = NULL; struct iattr newattrs; int error; error = mnt_want_write(path->mnt); if (error) return error; +retry_deleg: mutex_lock(&inode->i_mutex); error = security_path_chmod(path, mode); if (error) goto out_unlock; newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; - error = notify_change(path->dentry, &newattrs); + error = notify_change(path->dentry, &newattrs, &delegated_inode); out_unlock: mutex_unlock(&inode->i_mutex); + if (delegated_inode) { + error = break_deleg_wait(&delegated_inode); + if (!error) + goto retry_deleg; + } mnt_drop_write(path->mnt); return error; } @@ -523,6 +531,7 @@ SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode) static int chown_common(struct path *path, uid_t user, gid_t group) { struct inode *inode = path->dentry->d_inode; + struct inode *delegated_inode = NULL; int error; struct iattr newattrs; kuid_t uid; @@ -547,12 +556,17 @@ static int chown_common(struct path *path, uid_t user, gid_t group) if (!S_ISDIR(inode->i_mode)) newattrs.ia_valid |= ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; +retry_deleg: mutex_lock(&inode->i_mutex); error = security_path_chown(path, uid, gid); if (!error) - error = notify_change(path->dentry, &newattrs); + error = notify_change(path->dentry, &newattrs, &delegated_inode); mutex_unlock(&inode->i_mutex); - + if (delegated_inode) { + error = break_deleg_wait(&delegated_inode); + if (!error) + goto retry_deleg; + } return error; } diff --git a/fs/utimes.c b/fs/utimes.c index f4fb7ec..aa138d6 100644 --- a/fs/utimes.c +++ b/fs/utimes.c @@ -53,6 +53,7 @@ static int utimes_common(struct path *path, struct timespec *times) int error; struct iattr newattrs; struct inode *inode = path->dentry->d_inode; + struct inode *delegated_inode = NULL; error = mnt_want_write(path->mnt); if (error) @@ -101,9 +102,15 @@ static int utimes_common(struct path *path, struct timespec *times) goto mnt_drop_write_and_out; } } +retry_deleg: mutex_lock(&inode->i_mutex); - error = notify_change(path->dentry, &newattrs); + error = notify_change(path->dentry, &newattrs, &delegated_inode); mutex_unlock(&inode->i_mutex); + if (delegated_inode) { + error = break_deleg_wait(&delegated_inode); + if (!error) + goto retry_deleg; + } mnt_drop_write_and_out: mnt_drop_write(path->mnt); diff --git a/include/linux/fs.h b/include/linux/fs.h index a2403f9..638cdae 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2268,7 +2268,7 @@ extern void emergency_remount(void); #ifdef CONFIG_BLOCK extern sector_t bmap(struct inode *, sector_t); #endif -extern int notify_change(struct dentry *, struct iattr *); +extern int notify_change(struct dentry *, struct iattr *, struct inode **); extern int inode_permission(struct inode *, int); extern int generic_permission(struct inode *, int);