[PATCH 01/13] vfs: add i_op->dentry_open()
From: Miklos Szeredi
Add a new inode operation i_op->dentry_open(). This is for stacked filesystems
that want to return a struct file from a different filesystem.
Signed-off-by: Miklos Szeredi
---
Documentation/filesystems/Locking | 2 ++
Documentation/filesystems/vfs.txt | 7 +++
fs/namei.c| 9 ++---
fs/open.c | 23 +--
include/linux/fs.h| 2 ++
5 files changed, 38 insertions(+), 5 deletions(-)
diff --git a/Documentation/filesystems/Locking
b/Documentation/filesystems/Locking
index eba790134253..09a7b57d2f47 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -67,6 +67,7 @@ prototypes:
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
int (*tmpfile) (struct inode *, struct dentry *, umode_t);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
locking rules:
all may block
@@ -96,6 +97,7 @@ fiemap: no
update_time: no
atomic_open: yes
tmpfile: no
+dentry_open: no
Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on
victim.
diff --git a/Documentation/filesystems/vfs.txt
b/Documentation/filesystems/vfs.txt
index 617f6d70c077..938aea64b2fa 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -364,6 +364,7 @@ struct inode_operations {
int (*atomic_open)(struct inode *, struct dentry *, struct file *,
unsigned open_flag, umode_t create_mode, int *opened);
int (*tmpfile) (struct inode *, struct dentry *, umode_t);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
};
Again, all methods are called without any locks being held, unless
@@ -697,6 +698,12 @@ struct address_space_operations {
but instead uses bmap to find out where the blocks in the file
are and uses those addresses directly.
+ dentry_open: this is an alternative to f_op->open(), the difference is that
+ this method may open a file not necessarily originating from the same
+ filesystem as the one i_op->open() was called on. It may be
+ useful for stacking filesystems which want to allow native I/O directly
+ on underlying files.
+
invalidatepage: If a page has PagePrivate set, then invalidatepage
will be called when part or all of the page is to be removed
diff --git a/fs/namei.c b/fs/namei.c
index 80168273396b..a7cf0fb1f638 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3046,9 +3046,12 @@ finish_open_created:
error = may_open(>path, acc_mode, open_flag);
if (error)
goto out;
- file->f_path.mnt = nd->path.mnt;
- error = finish_open(file, nd->path.dentry, NULL, opened);
- if (error) {
+
+ BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */
+ error = vfs_open(>path, file, current_cred());
+ if (!error) {
+ *opened |= FILE_OPENED;
+ } else {
if (error == -EOPENSTALE)
goto stale_open;
goto out;
diff --git a/fs/open.c b/fs/open.c
index 9d64679cec73..3302cd25403f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -818,8 +818,7 @@ struct file *dentry_open(const struct path *path, int flags,
f = get_empty_filp();
if (!IS_ERR(f)) {
f->f_flags = flags;
- f->f_path = *path;
- error = do_dentry_open(f, NULL, cred);
+ error = vfs_open(path, f, cred);
if (!error) {
/* from now on we need fput() to dispose of f */
error = open_check_o_direct(f);
@@ -836,6 +835,26 @@ struct file *dentry_open(const struct path *path, int
flags,
}
EXPORT_SYMBOL(dentry_open);
+/**
+ * vfs_open - open the file at the given path
+ * @path: path to open
+ * @filp: newly allocated file with f_flag initialized
+ * @cred: credentials to use
+ */
+int vfs_open(const struct path *path, struct file *filp,
+const struct cred *cred)
+{
+ struct inode *inode = path->dentry->d_inode;
+
+ if (inode->i_op->dentry_open)
+ return inode->i_op->dentry_open(path->dentry, filp, cred);
+ else {
+ filp->f_path = *path;
+ return do_dentry_open(filp, NULL, cred);
+ }
+}
+EXPORT_SYMBOL(vfs_open);
+
static inline int build_open_flags(int flags, umode_t mode, struct open_flags
*op)
{
int lookup_flags = 0;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 878031227c57..d38875d70db2 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1513,6 +1513,7 @@ struct inode_operations {
umode_t create_mode, int *opened);
int (*tmpfile) (struct inode *, struct dentry *, umode_t);
int (*set_acl)(struct
[PATCH 01/13] vfs: add i_op-dentry_open()
From: Miklos Szeredi mszer...@suse.cz
Add a new inode operation i_op-dentry_open(). This is for stacked filesystems
that want to return a struct file from a different filesystem.
Signed-off-by: Miklos Szeredi mszer...@suse.cz
---
Documentation/filesystems/Locking | 2 ++
Documentation/filesystems/vfs.txt | 7 +++
fs/namei.c| 9 ++---
fs/open.c | 23 +--
include/linux/fs.h| 2 ++
5 files changed, 38 insertions(+), 5 deletions(-)
diff --git a/Documentation/filesystems/Locking
b/Documentation/filesystems/Locking
index eba790134253..09a7b57d2f47 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -67,6 +67,7 @@ prototypes:
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
int (*tmpfile) (struct inode *, struct dentry *, umode_t);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
locking rules:
all may block
@@ -96,6 +97,7 @@ fiemap: no
update_time: no
atomic_open: yes
tmpfile: no
+dentry_open: no
Additionally, -rmdir(), -unlink() and -rename() have -i_mutex on
victim.
diff --git a/Documentation/filesystems/vfs.txt
b/Documentation/filesystems/vfs.txt
index 617f6d70c077..938aea64b2fa 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -364,6 +364,7 @@ struct inode_operations {
int (*atomic_open)(struct inode *, struct dentry *, struct file *,
unsigned open_flag, umode_t create_mode, int *opened);
int (*tmpfile) (struct inode *, struct dentry *, umode_t);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
};
Again, all methods are called without any locks being held, unless
@@ -697,6 +698,12 @@ struct address_space_operations {
but instead uses bmap to find out where the blocks in the file
are and uses those addresses directly.
+ dentry_open: this is an alternative to f_op-open(), the difference is that
+ this method may open a file not necessarily originating from the same
+ filesystem as the one i_op-open() was called on. It may be
+ useful for stacking filesystems which want to allow native I/O directly
+ on underlying files.
+
invalidatepage: If a page has PagePrivate set, then invalidatepage
will be called when part or all of the page is to be removed
diff --git a/fs/namei.c b/fs/namei.c
index 80168273396b..a7cf0fb1f638 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3046,9 +3046,12 @@ finish_open_created:
error = may_open(nd-path, acc_mode, open_flag);
if (error)
goto out;
- file-f_path.mnt = nd-path.mnt;
- error = finish_open(file, nd-path.dentry, NULL, opened);
- if (error) {
+
+ BUG_ON(*opened FILE_OPENED); /* once it's opened, it's opened */
+ error = vfs_open(nd-path, file, current_cred());
+ if (!error) {
+ *opened |= FILE_OPENED;
+ } else {
if (error == -EOPENSTALE)
goto stale_open;
goto out;
diff --git a/fs/open.c b/fs/open.c
index 9d64679cec73..3302cd25403f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -818,8 +818,7 @@ struct file *dentry_open(const struct path *path, int flags,
f = get_empty_filp();
if (!IS_ERR(f)) {
f-f_flags = flags;
- f-f_path = *path;
- error = do_dentry_open(f, NULL, cred);
+ error = vfs_open(path, f, cred);
if (!error) {
/* from now on we need fput() to dispose of f */
error = open_check_o_direct(f);
@@ -836,6 +835,26 @@ struct file *dentry_open(const struct path *path, int
flags,
}
EXPORT_SYMBOL(dentry_open);
+/**
+ * vfs_open - open the file at the given path
+ * @path: path to open
+ * @filp: newly allocated file with f_flag initialized
+ * @cred: credentials to use
+ */
+int vfs_open(const struct path *path, struct file *filp,
+const struct cred *cred)
+{
+ struct inode *inode = path-dentry-d_inode;
+
+ if (inode-i_op-dentry_open)
+ return inode-i_op-dentry_open(path-dentry, filp, cred);
+ else {
+ filp-f_path = *path;
+ return do_dentry_open(filp, NULL, cred);
+ }
+}
+EXPORT_SYMBOL(vfs_open);
+
static inline int build_open_flags(int flags, umode_t mode, struct open_flags
*op)
{
int lookup_flags = 0;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 878031227c57..d38875d70db2 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1513,6 +1513,7 @@ struct inode_operations {
umode_t create_mode, int *opened);
int (*tmpfile) (struct inode *, struct dentry *, umode_t);
int
[PATCH 01/13] vfs-add-i_op-dentry_open
From: Miklos Szeredi
Add a new inode operation i_op->dentry_open(). This is for stacked filesystems
that want to return a struct file from a different filesystem.
Signed-off-by: Miklos Szeredi
---
Documentation/filesystems/Locking |2 ++
Documentation/filesystems/vfs.txt |7 +++
fs/namei.c|9 ++---
fs/open.c | 23 +--
include/linux/fs.h|2 ++
5 files changed, 38 insertions(+), 5 deletions(-)
diff --git a/Documentation/filesystems/Locking
b/Documentation/filesystems/Locking
index 0706d32..4331290 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -66,6 +66,7 @@ prototypes:
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
locking rules:
all may block
@@ -93,6 +94,7 @@ removexattr: yes
fiemap:no
update_time: no
atomic_open: yes
+dentry_open: no
Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on
victim.
diff --git a/Documentation/filesystems/vfs.txt
b/Documentation/filesystems/vfs.txt
index bc4b06b..f64a4d1 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -362,6 +362,7 @@ struct inode_operations {
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
};
Again, all methods are called without any locks being held, unless
@@ -681,6 +682,12 @@ struct address_space_operations {
but instead uses bmap to find out where the blocks in the file
are and uses those addresses directly.
+ dentry_open: this is an alternative to f_op->open(), the difference is that
+ this method may open a file not necessarily originating from the same
+ filesystem as the one i_op->open() was called on. It may be
+ useful for stacking filesystems which want to allow native I/O directly
+ on underlying files.
+
invalidatepage: If a page has PagePrivate set, then invalidatepage
will be called when part or all of the page is to be removed
diff --git a/fs/namei.c b/fs/namei.c
index 57ae9c8..c1c0c15 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2867,9 +2867,12 @@ finish_open_created:
error = may_open(>path, acc_mode, open_flag);
if (error)
goto out;
- file->f_path.mnt = nd->path.mnt;
- error = finish_open(file, nd->path.dentry, NULL, opened);
- if (error) {
+
+ BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */
+ error = vfs_open(>path, file, current_cred());
+ if (!error) {
+ *opened |= FILE_OPENED;
+ } else {
if (error == -EOPENSTALE)
goto stale_open;
goto out;
diff --git a/fs/open.c b/fs/open.c
index 6835446..b9d9f9e 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -828,8 +828,7 @@ struct file *dentry_open(const struct path *path, int flags,
f = get_empty_filp();
if (!IS_ERR(f)) {
f->f_flags = flags;
- f->f_path = *path;
- error = do_dentry_open(f, NULL, cred);
+ error = vfs_open(path, f, cred);
if (!error) {
/* from now on we need fput() to dispose of f */
error = open_check_o_direct(f);
@@ -846,6 +845,26 @@ struct file *dentry_open(const struct path *path, int
flags,
}
EXPORT_SYMBOL(dentry_open);
+/**
+ * vfs_open - open the file at the given path
+ * @path: path to open
+ * @filp: newly allocated file with f_flag initialized
+ * @cred: credentials to use
+ */
+int vfs_open(const struct path *path, struct file *filp,
+const struct cred *cred)
+{
+ struct inode *inode = path->dentry->d_inode;
+
+ if (inode->i_op->dentry_open)
+ return inode->i_op->dentry_open(path->dentry, filp, cred);
+ else {
+ filp->f_path = *path;
+ return do_dentry_open(filp, NULL, cred);
+ }
+}
+EXPORT_SYMBOL(vfs_open);
+
static inline int build_open_flags(int flags, umode_t mode, struct open_flags
*op)
{
int lookup_flags = 0;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2c28271..891c93d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1573,6 +1573,7 @@ struct inode_operations {
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*dentry_open)(struct dentry *, struct
[PATCH 01/13] vfs-add-i_op-dentry_open
From: Miklos Szeredi mszer...@suse.cz
Add a new inode operation i_op-dentry_open(). This is for stacked filesystems
that want to return a struct file from a different filesystem.
Signed-off-by: Miklos Szeredi mszer...@suse.cz
---
Documentation/filesystems/Locking |2 ++
Documentation/filesystems/vfs.txt |7 +++
fs/namei.c|9 ++---
fs/open.c | 23 +--
include/linux/fs.h|2 ++
5 files changed, 38 insertions(+), 5 deletions(-)
diff --git a/Documentation/filesystems/Locking
b/Documentation/filesystems/Locking
index 0706d32..4331290 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -66,6 +66,7 @@ prototypes:
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
locking rules:
all may block
@@ -93,6 +94,7 @@ removexattr: yes
fiemap:no
update_time: no
atomic_open: yes
+dentry_open: no
Additionally, -rmdir(), -unlink() and -rename() have -i_mutex on
victim.
diff --git a/Documentation/filesystems/vfs.txt
b/Documentation/filesystems/vfs.txt
index bc4b06b..f64a4d1 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -362,6 +362,7 @@ struct inode_operations {
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
};
Again, all methods are called without any locks being held, unless
@@ -681,6 +682,12 @@ struct address_space_operations {
but instead uses bmap to find out where the blocks in the file
are and uses those addresses directly.
+ dentry_open: this is an alternative to f_op-open(), the difference is that
+ this method may open a file not necessarily originating from the same
+ filesystem as the one i_op-open() was called on. It may be
+ useful for stacking filesystems which want to allow native I/O directly
+ on underlying files.
+
invalidatepage: If a page has PagePrivate set, then invalidatepage
will be called when part or all of the page is to be removed
diff --git a/fs/namei.c b/fs/namei.c
index 57ae9c8..c1c0c15 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2867,9 +2867,12 @@ finish_open_created:
error = may_open(nd-path, acc_mode, open_flag);
if (error)
goto out;
- file-f_path.mnt = nd-path.mnt;
- error = finish_open(file, nd-path.dentry, NULL, opened);
- if (error) {
+
+ BUG_ON(*opened FILE_OPENED); /* once it's opened, it's opened */
+ error = vfs_open(nd-path, file, current_cred());
+ if (!error) {
+ *opened |= FILE_OPENED;
+ } else {
if (error == -EOPENSTALE)
goto stale_open;
goto out;
diff --git a/fs/open.c b/fs/open.c
index 6835446..b9d9f9e 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -828,8 +828,7 @@ struct file *dentry_open(const struct path *path, int flags,
f = get_empty_filp();
if (!IS_ERR(f)) {
f-f_flags = flags;
- f-f_path = *path;
- error = do_dentry_open(f, NULL, cred);
+ error = vfs_open(path, f, cred);
if (!error) {
/* from now on we need fput() to dispose of f */
error = open_check_o_direct(f);
@@ -846,6 +845,26 @@ struct file *dentry_open(const struct path *path, int
flags,
}
EXPORT_SYMBOL(dentry_open);
+/**
+ * vfs_open - open the file at the given path
+ * @path: path to open
+ * @filp: newly allocated file with f_flag initialized
+ * @cred: credentials to use
+ */
+int vfs_open(const struct path *path, struct file *filp,
+const struct cred *cred)
+{
+ struct inode *inode = path-dentry-d_inode;
+
+ if (inode-i_op-dentry_open)
+ return inode-i_op-dentry_open(path-dentry, filp, cred);
+ else {
+ filp-f_path = *path;
+ return do_dentry_open(filp, NULL, cred);
+ }
+}
+EXPORT_SYMBOL(vfs_open);
+
static inline int build_open_flags(int flags, umode_t mode, struct open_flags
*op)
{
int lookup_flags = 0;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2c28271..891c93d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1573,6 +1573,7 @@ struct inode_operations {
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*dentry_open)(struct
[PATCH 01/13] vfs: add i_op->dentry_open()
From: Miklos Szeredi
Add a new inode operation i_op->dentry_open(). This is for stacked filesystems
that want to return a struct file from a different filesystem.
Signed-off-by: Miklos Szeredi
---
Documentation/filesystems/Locking |2 ++
Documentation/filesystems/vfs.txt |7 +++
fs/namei.c|9 ++---
fs/open.c | 23 +--
include/linux/fs.h|2 ++
5 files changed, 38 insertions(+), 5 deletions(-)
diff --git a/Documentation/filesystems/Locking
b/Documentation/filesystems/Locking
index e540a24..019fc72 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -64,6 +64,7 @@ prototypes:
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
locking rules:
all may block
@@ -92,6 +93,7 @@ removexattr: yes
fiemap:no
update_time: no
atomic_open: yes
+dentry_open: no
Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on
victim.
diff --git a/Documentation/filesystems/vfs.txt
b/Documentation/filesystems/vfs.txt
index 2ee133e..ea1379c 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -363,6 +363,7 @@ struct inode_operations {
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
};
Again, all methods are called without any locks being held, unless
@@ -692,6 +693,12 @@ struct address_space_operations {
but instead uses bmap to find out where the blocks in the file
are and uses those addresses directly.
+ dentry_open: this is an alternative to f_op->open(), the difference is that
+ this method may open a file not necessarily originating from the same
+ filesystem as the one i_op->open() was called on. It may be
+ useful for stacking filesystems which want to allow native I/O directly
+ on underlying files.
+
invalidatepage: If a page has PagePrivate set, then invalidatepage
will be called when part or all of the page is to be removed
diff --git a/fs/namei.c b/fs/namei.c
index dd1ed1b..829404a 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2822,9 +2822,12 @@ finish_open_created:
error = may_open(>path, acc_mode, open_flag);
if (error)
goto out;
- file->f_path.mnt = nd->path.mnt;
- error = finish_open(file, nd->path.dentry, NULL, opened);
- if (error) {
+
+ BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */
+ error = vfs_open(>path, file, current_cred());
+ if (!error) {
+ *opened |= FILE_OPENED;
+ } else {
if (error == -EOPENSTALE)
goto stale_open;
goto out;
diff --git a/fs/open.c b/fs/open.c
index e1f2cdb..d0f0ec7 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -787,8 +787,7 @@ struct file *dentry_open(const struct path *path, int flags,
return ERR_PTR(error);
f->f_flags = flags;
- f->f_path = *path;
- error = do_dentry_open(f, NULL, cred);
+ error = vfs_open(path, f, cred);
if (!error) {
error = open_check_o_direct(f);
if (error) {
@@ -803,6 +802,26 @@ struct file *dentry_open(const struct path *path, int
flags,
}
EXPORT_SYMBOL(dentry_open);
+/**
+ * vfs_open - open the file at the given path
+ * @path: path to open
+ * @filp: newly allocated file with f_flag initialized
+ * @cred: credentials to use
+ */
+int vfs_open(const struct path *path, struct file *filp,
+const struct cred *cred)
+{
+ struct inode *inode = path->dentry->d_inode;
+
+ if (inode->i_op->dentry_open)
+ return inode->i_op->dentry_open(path->dentry, filp, cred);
+ else {
+ filp->f_path = *path;
+ return do_dentry_open(filp, NULL, cred);
+ }
+}
+EXPORT_SYMBOL(vfs_open);
+
static void __put_unused_fd(struct files_struct *files, unsigned int fd)
{
struct fdtable *fdt = files_fdtable(files);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index aa11047..e372113 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1835,6 +1835,7 @@ struct inode_operations {
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
} cacheline_aligned;
struct seq_file;
@@ -2199,6 +2200,7
[PATCH 01/13] vfs: add i_op-dentry_open()
From: Miklos Szeredi mszer...@suse.cz
Add a new inode operation i_op-dentry_open(). This is for stacked filesystems
that want to return a struct file from a different filesystem.
Signed-off-by: Miklos Szeredi mszer...@suse.cz
---
Documentation/filesystems/Locking |2 ++
Documentation/filesystems/vfs.txt |7 +++
fs/namei.c|9 ++---
fs/open.c | 23 +--
include/linux/fs.h|2 ++
5 files changed, 38 insertions(+), 5 deletions(-)
diff --git a/Documentation/filesystems/Locking
b/Documentation/filesystems/Locking
index e540a24..019fc72 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -64,6 +64,7 @@ prototypes:
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
locking rules:
all may block
@@ -92,6 +93,7 @@ removexattr: yes
fiemap:no
update_time: no
atomic_open: yes
+dentry_open: no
Additionally, -rmdir(), -unlink() and -rename() have -i_mutex on
victim.
diff --git a/Documentation/filesystems/vfs.txt
b/Documentation/filesystems/vfs.txt
index 2ee133e..ea1379c 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -363,6 +363,7 @@ struct inode_operations {
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
};
Again, all methods are called without any locks being held, unless
@@ -692,6 +693,12 @@ struct address_space_operations {
but instead uses bmap to find out where the blocks in the file
are and uses those addresses directly.
+ dentry_open: this is an alternative to f_op-open(), the difference is that
+ this method may open a file not necessarily originating from the same
+ filesystem as the one i_op-open() was called on. It may be
+ useful for stacking filesystems which want to allow native I/O directly
+ on underlying files.
+
invalidatepage: If a page has PagePrivate set, then invalidatepage
will be called when part or all of the page is to be removed
diff --git a/fs/namei.c b/fs/namei.c
index dd1ed1b..829404a 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2822,9 +2822,12 @@ finish_open_created:
error = may_open(nd-path, acc_mode, open_flag);
if (error)
goto out;
- file-f_path.mnt = nd-path.mnt;
- error = finish_open(file, nd-path.dentry, NULL, opened);
- if (error) {
+
+ BUG_ON(*opened FILE_OPENED); /* once it's opened, it's opened */
+ error = vfs_open(nd-path, file, current_cred());
+ if (!error) {
+ *opened |= FILE_OPENED;
+ } else {
if (error == -EOPENSTALE)
goto stale_open;
goto out;
diff --git a/fs/open.c b/fs/open.c
index e1f2cdb..d0f0ec7 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -787,8 +787,7 @@ struct file *dentry_open(const struct path *path, int flags,
return ERR_PTR(error);
f-f_flags = flags;
- f-f_path = *path;
- error = do_dentry_open(f, NULL, cred);
+ error = vfs_open(path, f, cred);
if (!error) {
error = open_check_o_direct(f);
if (error) {
@@ -803,6 +802,26 @@ struct file *dentry_open(const struct path *path, int
flags,
}
EXPORT_SYMBOL(dentry_open);
+/**
+ * vfs_open - open the file at the given path
+ * @path: path to open
+ * @filp: newly allocated file with f_flag initialized
+ * @cred: credentials to use
+ */
+int vfs_open(const struct path *path, struct file *filp,
+const struct cred *cred)
+{
+ struct inode *inode = path-dentry-d_inode;
+
+ if (inode-i_op-dentry_open)
+ return inode-i_op-dentry_open(path-dentry, filp, cred);
+ else {
+ filp-f_path = *path;
+ return do_dentry_open(filp, NULL, cred);
+ }
+}
+EXPORT_SYMBOL(vfs_open);
+
static void __put_unused_fd(struct files_struct *files, unsigned int fd)
{
struct fdtable *fdt = files_fdtable(files);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index aa11047..e372113 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1835,6 +1835,7 @@ struct inode_operations {
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
} cacheline_aligned;
struct seq_file;
@@
