Messages in this thread Patch in this message | | | Subject | [PATCH 04/22] elevate writer count for chown and friends | From | Dave Hansen <> | Date | Fri, 09 Feb 2007 14:53:31 -0800 |
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chown/chmod,etc... don't call permission in the same way that the normal "open for write" calls do. They still write to the filesystem, so bump the write count during these operations.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com> ---
lxc-dave/fs/open.c | 37 +++++++++++++++++++++++++++++++++---- 1 file changed, 33 insertions(+), 4 deletions(-)
diff -puN fs/open.c~06-24-elevate-writer-count-for-chown-and-friends fs/open.c --- lxc/fs/open.c~06-24-elevate-writer-count-for-chown-and-friends 2007-02-09 14:26:48.000000000 -0800 +++ lxc-dave/fs/open.c 2007-02-09 14:26:48.000000000 -0800 @@ -511,9 +511,12 @@ asmlinkage long sys_fchmod(unsigned int err = -EROFS; if (IS_RDONLY(inode)) goto out_putf; + err = mnt_want_write(file->f_vfsmnt); + if (err) + goto out_putf; err = -EPERM; if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) - goto out_putf; + goto out_drop_write; mutex_lock(&inode->i_mutex); if (mode == (mode_t) -1) mode = inode->i_mode; @@ -522,6 +525,8 @@ asmlinkage long sys_fchmod(unsigned int err = notify_change(dentry, &newattrs); mutex_unlock(&inode->i_mutex); +out_drop_write: + mnt_drop_write(file->f_vfsmnt); out_putf: fput(file); out: @@ -541,13 +546,16 @@ asmlinkage long sys_fchmodat(int dfd, co goto out; inode = nd.dentry->d_inode; + error = mnt_want_write(nd.mnt); + if (error) + goto dput_and_out; error = -EROFS; if (IS_RDONLY(inode)) - goto dput_and_out; + goto out_drop_write; error = -EPERM; if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) - goto dput_and_out; + goto out_drop_write; mutex_lock(&inode->i_mutex); if (mode == (mode_t) -1) @@ -557,6 +565,8 @@ asmlinkage long sys_fchmodat(int dfd, co error = notify_change(nd.dentry, &newattrs); mutex_unlock(&inode->i_mutex); +out_drop_write: + mnt_drop_write(nd.mnt); dput_and_out: path_release(&nd); out: @@ -582,7 +592,7 @@ static int chown_common(struct dentry * error = -EROFS; if (IS_RDONLY(inode)) goto out; - error = -EPERM; + error = -EPERM; if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) goto out; newattrs.ia_valid = ATTR_CTIME; @@ -611,7 +621,12 @@ asmlinkage long sys_chown(const char __u error = user_path_walk(filename, &nd); if (error) goto out; + error = mnt_want_write(nd.mnt); + if (error) + goto out_release; error = chown_common(nd.dentry, user, group); + mnt_drop_write(nd.mnt); +out_release: path_release(&nd); out: return error; @@ -631,7 +646,12 @@ asmlinkage long sys_fchownat(int dfd, co error = __user_walk_fd(dfd, filename, follow, &nd); if (error) goto out; + error = mnt_want_write(nd.mnt); + if (error) + goto out_release; error = chown_common(nd.dentry, user, group); + mnt_drop_write(nd.mnt); +out_release: path_release(&nd); out: return error; @@ -645,7 +665,11 @@ asmlinkage long sys_lchown(const char __ error = user_path_walk_link(filename, &nd); if (error) goto out; + error = mnt_want_write(nd.mnt); + if (error) + goto out_release; error = chown_common(nd.dentry, user, group); +out_release: path_release(&nd); out: return error; @@ -662,9 +686,14 @@ asmlinkage long sys_fchown(unsigned int if (!file) goto out; + error = mnt_want_write(file->f_vfsmnt); + if (error) + goto out_fput; dentry = file->f_path.dentry; audit_inode(NULL, dentry->d_inode); error = chown_common(dentry, user, group); + mnt_drop_write(file->f_vfsmnt); +out_fput: fput(file); out: return error; _ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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