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fs: no games with DCACHE_UNHASHED 

Filesystems outside the regular namespace do not have to clear DCACHE_UNHASHED
in order to have a working /proc/$pid/fd/XXX. Nothing in proc prevents the
fd link from being used if its dentry is not in the hash.

Also, it does not get put into the dcache hash if DCACHE_UNHASHED is clear;
that depends on the filesystem calling d_add or d_rehash.

So delete the misleading comments and needless code.

Acked-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Nick Piggin 2009-11-18 05:30:19 +01:00 committed by Al Viro
parent b9aff027b2
commit a3a065e3f1
3 changed files with 0 additions and 50 deletions
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13
fs/anon_inodes.c
View File

@ -35,16 +35,6 @@ static int anon_inodefs_get_sb(struct file_system_type *fs_type, int flags,
mnt);
}
static int anon_inodefs_delete_dentry(struct dentry *dentry)
{
/*
* We faked vfs to believe the dentry was hashed when we created it.
* Now we restore the flag so that dput() will work correctly.
*/
dentry->d_flags |= DCACHE_UNHASHED;
return 1;
}
/*
* anon_inodefs_dname() is called from d_path().
*/
@ -60,7 +50,6 @@ static struct file_system_type anon_inode_fs_type = {
.kill_sb = kill_anon_super,
};
static const struct dentry_operations anon_inodefs_dentry_operations = {
.d_delete = anon_inodefs_delete_dentry,
.d_dname = anon_inodefs_dname,
};
@ -129,8 +118,6 @@ struct file *anon_inode_getfile(const char *name,
atomic_inc(&anon_inode_inode->i_count);
path.dentry->d_op = &anon_inodefs_dentry_operations;
/* Do not publish this dentry inside the global dentry hash table */
path.dentry->d_flags &= ~DCACHE_UNHASHED;
d_instantiate(path.dentry, anon_inode_inode);
error = -ENFILE;

18
fs/pipe.c
View File

@ -906,17 +906,6 @@ void free_pipe_info(struct inode *inode)
}
static struct vfsmount *pipe_mnt __read_mostly;
static int pipefs_delete_dentry(struct dentry *dentry)
{
/*
* At creation time, we pretended this dentry was hashed
* (by clearing DCACHE_UNHASHED bit in d_flags)
* At delete time, we restore the truth : not hashed.
* (so that dput() can proceed correctly)
*/
dentry->d_flags |= DCACHE_UNHASHED;
return 0;
}
/*
* pipefs_dname() is called from d_path().
@ -928,7 +917,6 @@ static char *pipefs_dname(struct dentry *dentry, char *buffer, int buflen)
}
static const struct dentry_operations pipefs_dentry_operations = {
.d_delete = pipefs_delete_dentry,
.d_dname = pipefs_dname,
};
@ -989,12 +977,6 @@ struct file *create_write_pipe(int flags)
path.mnt = mntget(pipe_mnt);
path.dentry->d_op = &pipefs_dentry_operations;
/*
* We dont want to publish this dentry into global dentry hash table.
* We pretend dentry is already hashed, by unsetting DCACHE_UNHASHED
* This permits a working /proc/$pid/fd/XXX on pipes
*/
path.dentry->d_flags &= ~DCACHE_UNHASHED;
d_instantiate(path.dentry, inode);
err = -ENFILE;

19
net/socket.c
View File

@ -312,18 +312,6 @@ static struct file_system_type sock_fs_type = {
.kill_sb = kill_anon_super,
};
static int sockfs_delete_dentry(struct dentry *dentry)
{
/*
* At creation time, we pretended this dentry was hashed
* (by clearing DCACHE_UNHASHED bit in d_flags)
* At delete time, we restore the truth : not hashed.
* (so that dput() can proceed correctly)
*/
dentry->d_flags |= DCACHE_UNHASHED;
return 0;
}
/*
* sockfs_dname() is called from d_path().
*/
@ -334,7 +322,6 @@ static char *sockfs_dname(struct dentry *dentry, char *buffer, int buflen)
}
static const struct dentry_operations sockfs_dentry_operations = {
.d_delete = sockfs_delete_dentry,
.d_dname = sockfs_dname,
};
@ -374,12 +361,6 @@ static int sock_alloc_file(struct socket *sock, struct file **f, int flags)
path.mnt = mntget(sock_mnt);
path.dentry->d_op = &sockfs_dentry_operations;
/*
* We dont want to push this dentry into global dentry hash table.
* We pretend dentry is already hashed, by unsetting DCACHE_UNHASHED
* This permits a working /proc/$pid/fd/XXX on sockets
*/
path.dentry->d_flags &= ~DCACHE_UNHASHED;
d_instantiate(path.dentry, SOCK_INODE(sock));
SOCK_INODE(sock)->i_fop = &socket_file_ops;