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Message-Id: <1338901832-14049-16-git-send-email-miklos@szeredi.hu>
Date: Tue, 5 Jun 2012 15:10:26 +0200
From: Miklos Szeredi <miklos@...redi.hu>
To: viro@...IV.linux.org.uk
Cc: linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
hch@...radead.org, torvalds@...ux-foundation.org,
dhowells@...hat.com, mszeredi@...e.cz,
Eric Van Hensbergen <ericvh@...il.com>
Subject: [PATCH 15/21] 9p: implement i_op->atomic_open()
From: Miklos Szeredi <mszeredi@...e.cz>
Add an ->atomic_open implementation which replaces the atomic open+create
operation implemented via ->create. No functionality is changed.
Signed-off-by: Miklos Szeredi <mszeredi@...e.cz>
CC: Eric Van Hensbergen <ericvh@...il.com>
---
fs/9p/vfs_inode.c | 169 +++++++++++++++++++++++++++++-------------------
fs/9p/vfs_inode_dotl.c | 52 ++++++++++-----
2 files changed, 137 insertions(+), 84 deletions(-)
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 57ccb75..e8c42ce 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -712,11 +712,14 @@ error:
}
/**
- * v9fs_vfs_create - VFS hook to create files
+ * v9fs_vfs_create - VFS hook to create a regular file
+ *
+ * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called
+ * for mknod(2).
+ *
* @dir: directory inode that is being created
* @dentry: dentry that is being deleted
* @mode: create permissions
- * @nd: path information
*
*/
@@ -724,76 +727,19 @@ static int
v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
struct nameidata *nd)
{
- int err;
- u32 perm;
- int flags;
- struct file *filp;
- struct v9fs_inode *v9inode;
- struct v9fs_session_info *v9ses;
- struct p9_fid *fid, *inode_fid;
-
- err = 0;
- fid = NULL;
- v9ses = v9fs_inode2v9ses(dir);
- perm = unixmode2p9mode(v9ses, mode);
- if (nd)
- flags = nd->intent.open.flags;
- else
- flags = O_RDWR;
+ struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
+ u32 perm = unixmode2p9mode(v9ses, mode);
+ struct p9_fid *fid;
- fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
- v9fs_uflags2omode(flags,
- v9fs_proto_dotu(v9ses)));
- if (IS_ERR(fid)) {
- err = PTR_ERR(fid);
- fid = NULL;
- goto error;
- }
+ /* P9_OEXCL? */
+ fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
+ if (IS_ERR(fid))
+ return PTR_ERR(fid);
v9fs_invalidate_inode_attr(dir);
- /* if we are opening a file, assign the open fid to the file */
- if (nd) {
- v9inode = V9FS_I(dentry->d_inode);
- mutex_lock(&v9inode->v_mutex);
- if (v9ses->cache && !v9inode->writeback_fid &&
- ((flags & O_ACCMODE) != O_RDONLY)) {
- /*
- * clone a fid and add it to writeback_fid
- * we do it during open time instead of
- * page dirty time via write_begin/page_mkwrite
- * because we want write after unlink usecase
- * to work.
- */
- inode_fid = v9fs_writeback_fid(dentry);
- if (IS_ERR(inode_fid)) {
- err = PTR_ERR(inode_fid);
- mutex_unlock(&v9inode->v_mutex);
- goto error;
- }
- v9inode->writeback_fid = (void *) inode_fid;
- }
- mutex_unlock(&v9inode->v_mutex);
- filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
- if (IS_ERR(filp)) {
- err = PTR_ERR(filp);
- goto error;
- }
-
- filp->private_data = fid;
-#ifdef CONFIG_9P_FSCACHE
- if (v9ses->cache)
- v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
-#endif
- } else
- p9_client_clunk(fid);
+ p9_client_clunk(fid);
return 0;
-
-error:
- if (fid)
- p9_client_clunk(fid);
-
- return err;
}
/**
@@ -910,6 +856,93 @@ error:
return ERR_PTR(result);
}
+static struct file *
+v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
+ struct opendata *od, unsigned flags, umode_t mode,
+ bool *created)
+{
+ int err;
+ u32 perm;
+ struct file *filp;
+ struct v9fs_inode *v9inode;
+ struct v9fs_session_info *v9ses;
+ struct p9_fid *fid, *inode_fid;
+ struct dentry *res = NULL;
+
+ if (d_unhashed(dentry)) {
+ res = v9fs_vfs_lookup(dir, dentry, NULL);
+ if (IS_ERR(res))
+ return ERR_CAST(res);
+
+ if (res)
+ dentry = res;
+ }
+
+ /* Only creates */
+ if (!(flags & O_CREAT) || dentry->d_inode) {
+ finish_no_open(od, res);
+ return NULL;
+ }
+
+ err = 0;
+ fid = NULL;
+ v9ses = v9fs_inode2v9ses(dir);
+ perm = unixmode2p9mode(v9ses, mode);
+ fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
+ v9fs_uflags2omode(flags,
+ v9fs_proto_dotu(v9ses)));
+ if (IS_ERR(fid)) {
+ err = PTR_ERR(fid);
+ fid = NULL;
+ goto error;
+ }
+
+ v9fs_invalidate_inode_attr(dir);
+ v9inode = V9FS_I(dentry->d_inode);
+ mutex_lock(&v9inode->v_mutex);
+ if (v9ses->cache && !v9inode->writeback_fid &&
+ ((flags & O_ACCMODE) != O_RDONLY)) {
+ /*
+ * clone a fid and add it to writeback_fid
+ * we do it during open time instead of
+ * page dirty time via write_begin/page_mkwrite
+ * because we want write after unlink usecase
+ * to work.
+ */
+ inode_fid = v9fs_writeback_fid(dentry);
+ if (IS_ERR(inode_fid)) {
+ err = PTR_ERR(inode_fid);
+ mutex_unlock(&v9inode->v_mutex);
+ goto error;
+ }
+ v9inode->writeback_fid = (void *) inode_fid;
+ }
+ mutex_unlock(&v9inode->v_mutex);
+ filp = finish_open(od, dentry, generic_file_open);
+ if (IS_ERR(filp)) {
+ err = PTR_ERR(filp);
+ goto error;
+ }
+
+ filp->private_data = fid;
+#ifdef CONFIG_9P_FSCACHE
+ if (v9ses->cache)
+ v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
+#endif
+
+ *created = true;
+out:
+ dput(res);
+ return filp;
+
+error:
+ if (fid)
+ p9_client_clunk(fid);
+
+ filp = ERR_PTR(err);
+ goto out;
+}
+
/**
* v9fs_vfs_unlink - VFS unlink hook to delete an inode
* @i: inode that is being unlinked
@@ -1488,6 +1521,7 @@ out:
static const struct inode_operations v9fs_dir_inode_operations_dotu = {
.create = v9fs_vfs_create,
.lookup = v9fs_vfs_lookup,
+ .atomic_open = v9fs_vfs_atomic_open,
.symlink = v9fs_vfs_symlink,
.link = v9fs_vfs_link,
.unlink = v9fs_vfs_unlink,
@@ -1502,6 +1536,7 @@ static const struct inode_operations v9fs_dir_inode_operations_dotu = {
static const struct inode_operations v9fs_dir_inode_operations = {
.create = v9fs_vfs_create,
.lookup = v9fs_vfs_lookup,
+ .atomic_open = v9fs_vfs_atomic_open,
.unlink = v9fs_vfs_unlink,
.mkdir = v9fs_vfs_mkdir,
.rmdir = v9fs_vfs_rmdir,
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index e3dd2a1..a354fe2 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -230,7 +230,6 @@ int v9fs_open_to_dotl_flags(int flags)
* @dir: directory inode that is being created
* @dentry: dentry that is being deleted
* @mode: create permissions
- * @nd: path information
*
*/
@@ -238,9 +237,16 @@ static int
v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
struct nameidata *nd)
{
+ return v9fs_vfs_mknod_dotl(dir, dentry, omode, 0);
+}
+
+static struct file *
+v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
+ struct opendata *od, unsigned flags, umode_t omode,
+ bool *created)
+{
int err = 0;
gid_t gid;
- int flags;
umode_t mode;
char *name = NULL;
struct file *filp;
@@ -251,19 +257,25 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
struct p9_fid *dfid, *ofid, *inode_fid;
struct v9fs_session_info *v9ses;
struct posix_acl *pacl = NULL, *dacl = NULL;
+ struct dentry *res = NULL;
- v9ses = v9fs_inode2v9ses(dir);
- if (nd)
- flags = nd->intent.open.flags;
- else {
- /*
- * create call without LOOKUP_OPEN is due
- * to mknod of regular files. So use mknod
- * operation.
- */
- return v9fs_vfs_mknod_dotl(dir, dentry, omode, 0);
+ if (d_unhashed(dentry)) {
+ res = v9fs_vfs_lookup(dir, dentry, NULL);
+ if (IS_ERR(res))
+ return ERR_CAST(res);
+
+ if (res)
+ dentry = res;
+ }
+
+ /* Only creates */
+ if (!(flags & O_CREAT) || dentry->d_inode) {
+ finish_no_open(od, res);
+ return NULL;
}
+ v9ses = v9fs_inode2v9ses(dir);
+
name = (char *) dentry->d_name.name;
p9_debug(P9_DEBUG_VFS, "name:%s flags:0x%x mode:0x%hx\n",
name, flags, omode);
@@ -272,7 +284,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
if (IS_ERR(dfid)) {
err = PTR_ERR(dfid);
p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
- return err;
+ goto err_return;
}
/* clone a fid to use for creation */
@@ -280,7 +292,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
if (IS_ERR(ofid)) {
err = PTR_ERR(ofid);
p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
- return err;
+ goto err_return;
}
gid = v9fs_get_fsgid_for_create(dir);
@@ -345,7 +357,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
}
mutex_unlock(&v9inode->v_mutex);
/* Since we are opening a file, assign the open fid to the file */
- filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
+ filp = finish_open(od, dentry, generic_file_open);
if (IS_ERR(filp)) {
err = PTR_ERR(filp);
goto err_clunk_old_fid;
@@ -355,7 +367,10 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
if (v9ses->cache)
v9fs_cache_inode_set_cookie(inode, filp);
#endif
- return 0;
+ *created = true;
+out:
+ dput(res);
+ return filp;
error:
if (fid)
@@ -364,7 +379,9 @@ err_clunk_old_fid:
if (ofid)
p9_client_clunk(ofid);
v9fs_set_create_acl(NULL, &dacl, &pacl);
- return err;
+err_return:
+ filp = ERR_PTR(err);
+ goto out;
}
/**
@@ -982,6 +999,7 @@ out:
const struct inode_operations v9fs_dir_inode_operations_dotl = {
.create = v9fs_vfs_create_dotl,
+ .atomic_open = v9fs_vfs_atomic_open_dotl,
.lookup = v9fs_vfs_lookup,
.link = v9fs_vfs_link_dotl,
.symlink = v9fs_vfs_symlink_dotl,
--
1.7.7
--
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