kernel.git/fs/nilfs2/super.c, branch linux-3.14.y

git simplify nilfs check for busy subtree

2013-09-04T02:52:50Z

Reviewed-by: Ryusuke Konishi Signed-off-by: Al Viro

helper for reading ->d_count

2013-07-05T14:59:33Z

Signed-off-by: Al Viro

] nilfs2: use atomic64_t type for inodes_count and blocks_count fields in nilfs_root struct

2013-07-03T23:08:01Z

The cp_inodes_count and cp_blocks_count are represented as __le64 type in on-disk structure (struct nilfs_checkpoint). But analogous fields in in-core structure (struct nilfs_root) are represented by atomic_t type. This patch replaces atomic_t on atomic64_t type in representation of inodes_count and blocks_count fields in struct nilfs_root. Signed-off-by: Vyacheslav Dubeyko Acked-by: Ryusuke Konishi Acked-by: Joern Engel Cc: Clemens Eisserer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: implement calculation of free inodes count

2013-07-03T23:08:01Z

Currently, NILFS2 returns 0 as free inodes count (f_ffree) and current used inodes count as total file nodes in file system (f_files): df -i Filesystem Inodes IUsed IFree IUse% Mounted on /dev/loop0 2 2 0 100% /mnt/nilfs2 This patch implements real calculation of free inodes count. First of all, it is calculated total file nodes in file system as (desc_blocks_count * groups_per_desc_block * entries_per_group). Then, it is calculated free inodes count as difference the total file nodes and used inodes count. As a result, we have such output for NILFS2: df -i Filesystem Inodes IUsed IFree IUse% Mounted on /dev/loop0 4194304 2114701 2079603 51% /mnt/nilfs2 Reported-by: Clemens Eisserer Signed-off-by: Vyacheslav Dubeyko Signed-off-by: Ryusuke Konishi Tested-by: Vyacheslav Dubeyko Cc: Joern Engel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs: Limit sys_mount to only request filesystem modules.

2013-03-04T03:36:31Z

Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn Acked-by: Kees Cook Reported-by: Kees Cook Signed-off-by: "Eric W. Biederman"

fs: push rcu_barrier() from deactivate_locked_super() to filesystems

2012-10-03T01:35:55Z

There's no reason to call rcu_barrier() on every deactivate_locked_super(). We only need to make sure that all delayed rcu free inodes are flushed before we destroy related cache. Removing rcu_barrier() from deactivate_locked_super() affects some fast paths. E.g. on my machine exit_group() of a last process in IPC namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time. Signed-off-by: Kirill A. Shutemov Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Al Viro

nilfs2: nuke write_super from comments

2012-08-04T08:15:38Z

The '->write_super' superblock method is gone, and this patch removes all the references to 'write_super' from ntfs. Cc: KONISHI Ryusuke Signed-off-by: Artem Bityutskiy Signed-off-by: Al Viro

nilfs2: fix deadlock issue between chcp and thaw ioctls

2012-07-31T00:25:19Z

An fs-thaw ioctl causes deadlock with a chcp or mkcp -s command: chcp D ffff88013870f3d0 0 1325 1324 0x00000004 ... Call Trace: nilfs_transaction_begin+0x11c/0x1a0 [nilfs2] wake_up_bit+0x20/0x20 copy_from_user+0x18/0x30 [nilfs2] nilfs_ioctl_change_cpmode+0x7d/0xcf [nilfs2] nilfs_ioctl+0x252/0x61a [nilfs2] do_page_fault+0x311/0x34c get_unmapped_area+0x132/0x14e do_vfs_ioctl+0x44b/0x490 __set_task_blocked+0x5a/0x61 vm_mmap_pgoff+0x76/0x87 __set_current_blocked+0x30/0x4a sys_ioctl+0x4b/0x6f system_call_fastpath+0x16/0x1b thaw D ffff88013870d890 0 1352 1351 0x00000004 ... Call Trace: rwsem_down_failed_common+0xdb/0x10f call_rwsem_down_write_failed+0x13/0x20 down_write+0x25/0x27 thaw_super+0x13/0x9e do_vfs_ioctl+0x1f5/0x490 vm_mmap_pgoff+0x76/0x87 sys_ioctl+0x4b/0x6f filp_close+0x64/0x6c system_call_fastpath+0x16/0x1b where the thaw ioctl deadlocked at thaw_super() when called while chcp was waiting at nilfs_transaction_begin() called from nilfs_ioctl_change_cpmode(). This deadlock is 100% reproducible. This is because nilfs_ioctl_change_cpmode() first locks sb->s_umount in read mode and then waits for unfreezing in nilfs_transaction_begin(), whereas thaw_super() locks sb->s_umount in write mode. The locking of sb->s_umount here was intended to make snapshot mounts and the downgrade of snapshots to checkpoints exclusive. This fixes the deadlock issue by replacing the sb->s_umount usage in nilfs_ioctl_change_cpmode() with a dedicated mutex which protects snapshot mounts. Signed-off-by: Ryusuke Konishi Cc: Fernando Luis Vazquez Cao Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: remove references to long gone super operations

2012-07-31T00:25:19Z

->delete_inode(), ->write_super_lockfs(), ->unlockfs() are gone so remove references to them in the NTFS code. Noticed while cleaning up the fsfreeze mess. Signed-off-by: Fernando Luis Vazquez Cao Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

VFS: Pass mount flags to sget()

2012-07-14T12:38:34Z

Pass mount flags to sget() so that it can use them in initialising a new superblock before the set function is called. They could also be passed to the compare function. Signed-off-by: David Howells Signed-off-by: Al Viro