From f71381fcdc3ab615f55278d435a9f35542dc9e63 Mon Sep 17 00:00:00 2001 From: Ian Kent Date: Fri, 8 Jul 2022 09:43:01 +0800 Subject: autofs: use inode permission method for write access Patch series "autofs: misc patches". This series contains several patches that resulted mostly from comments made by Al Viro (quite a long time ago now). This patch (of 5): Eliminate some code duplication from mkdir/rmdir/symlink/unlink methods by using the inode operation .permission(). Link: https://lkml.kernel.org/r/165724445154.30914.10970894936827635879.stgit@donald.themaw.net Link: https://lkml.kernel.org/r/165724458096.30914.13499431569758625806.stgit@donald.themaw.net Signed-off-by: Ian Kent Cc: Al Viro Cc: David Howells Cc: Miklos Szeredi Signed-off-by: Andrew Morton --- fs/autofs/root.c | 63 ++++++++++++++++++++------------------------------------ 1 file changed, 22 insertions(+), 41 deletions(-) (limited to 'fs/autofs') diff --git a/fs/autofs/root.c b/fs/autofs/root.c index 91fe4548c256..fef6ed991022 100644 --- a/fs/autofs/root.c +++ b/fs/autofs/root.c @@ -10,6 +10,7 @@ #include "autofs_i.h" +static int autofs_dir_permission(struct user_namespace *, struct inode *, int); static int autofs_dir_symlink(struct user_namespace *, struct inode *, struct dentry *, const char *); static int autofs_dir_unlink(struct inode *, struct dentry *); @@ -50,6 +51,7 @@ const struct file_operations autofs_dir_operations = { const struct inode_operations autofs_dir_inode_operations = { .lookup = autofs_lookup, + .permission = autofs_dir_permission, .unlink = autofs_dir_unlink, .symlink = autofs_dir_symlink, .mkdir = autofs_dir_mkdir, @@ -526,11 +528,30 @@ static struct dentry *autofs_lookup(struct inode *dir, return NULL; } +static int autofs_dir_permission(struct user_namespace *mnt_userns, + struct inode *inode, int mask) +{ + if (mask & MAY_WRITE) { + struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb); + + if (!autofs_oz_mode(sbi)) + return -EACCES; + + /* autofs_oz_mode() needs to allow path walks when the + * autofs mount is catatonic but the state of an autofs + * file system needs to be preserved over restarts. + */ + if (sbi->flags & AUTOFS_SBI_CATATONIC) + return -EACCES; + } + + return generic_permission(mnt_userns, inode, mask); +} + static int autofs_dir_symlink(struct user_namespace *mnt_userns, struct inode *dir, struct dentry *dentry, const char *symname) { - struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb); struct autofs_info *ino = autofs_dentry_ino(dentry); struct autofs_info *p_ino; struct inode *inode; @@ -539,16 +560,6 @@ static int autofs_dir_symlink(struct user_namespace *mnt_userns, pr_debug("%s <- %pd\n", symname, dentry); - if (!autofs_oz_mode(sbi)) - return -EACCES; - - /* autofs_oz_mode() needs to allow path walks when the - * autofs mount is catatonic but the state of an autofs - * file system needs to be preserved over restarts. - */ - if (sbi->flags & AUTOFS_SBI_CATATONIC) - return -EACCES; - BUG_ON(!ino); autofs_clean_ino(ino); @@ -601,16 +612,6 @@ static int autofs_dir_unlink(struct inode *dir, struct dentry *dentry) struct autofs_info *ino = autofs_dentry_ino(dentry); struct autofs_info *p_ino; - if (!autofs_oz_mode(sbi)) - return -EACCES; - - /* autofs_oz_mode() needs to allow path walks when the - * autofs mount is catatonic but the state of an autofs - * file system needs to be preserved over restarts. - */ - if (sbi->flags & AUTOFS_SBI_CATATONIC) - return -EACCES; - ino->count--; p_ino = autofs_dentry_ino(dentry->d_parent); p_ino->count--; @@ -683,16 +684,6 @@ static int autofs_dir_rmdir(struct inode *dir, struct dentry *dentry) pr_debug("dentry %p, removing %pd\n", dentry, dentry); - if (!autofs_oz_mode(sbi)) - return -EACCES; - - /* autofs_oz_mode() needs to allow path walks when the - * autofs mount is catatonic but the state of an autofs - * file system needs to be preserved over restarts. - */ - if (sbi->flags & AUTOFS_SBI_CATATONIC) - return -EACCES; - if (ino->count != 1) return -ENOTEMPTY; @@ -726,16 +717,6 @@ static int autofs_dir_mkdir(struct user_namespace *mnt_userns, struct autofs_info *p_ino; struct inode *inode; - if (!autofs_oz_mode(sbi)) - return -EACCES; - - /* autofs_oz_mode() needs to allow path walks when the - * autofs mount is catatonic but the state of an autofs - * file system needs to be preserved over restarts. - */ - if (sbi->flags & AUTOFS_SBI_CATATONIC) - return -EACCES; - pr_debug("dentry %p, creating %pd\n", dentry, dentry); BUG_ON(!ino); -- cgit