kernel.git/fs/nilfs2/ioctl.c, branch linux-3.4.y

nilfs2: fix fix very long mount time issue

2013-02-11T16:47:18Z

commit a9bae189542e71f91e61a4428adf6e5a7dfe8063 upstream. There exists a situation when GC can work in background alone without any other filesystem activity during significant time. The nilfs_clean_segments() method calls nilfs_segctor_construct() that updates superblocks in the case of NILFS_SC_SUPER_ROOT and THE_NILFS_DISCONTINUED flags are set. But when GC is working alone the nilfs_clean_segments() is called with unset THE_NILFS_DISCONTINUED flag. As a result, the update of superblocks doesn't occurred all this time and in the case of SPOR superblocks keep very old values of last super root placement. SYMPTOMS: Trying to mount a NILFS2 volume after SPOR in such environment ends with very long mounting time (it can achieve about several hours in some cases). REPRODUCING PATH: 1. It needs to use external USB HDD, disable automount and doesn't make any additional filesystem activity on the NILFS2 volume. 2. Generate temporary file with size about 100 - 500 GB (for example, dd if=/dev/zero of= bs=1073741824 count=200). The size of file defines duration of GC working. 3. Then it needs to delete file. 4. Start GC manually by means of command "nilfs-clean -p 0". When you start GC by means of such way then, at the end, superblocks is updated by once. So, for simulation of SPOR, it needs to wait sometime (15 - 40 minutes) and simply switch off USB HDD manually. 5. Switch on USB HDD again and try to mount NILFS2 volume. As a result, NILFS2 volume will mount during very long time. REPRODUCIBILITY: 100% FIX: This patch adds checking that superblocks need to update and set THE_NILFS_DISCONTINUED flag before nilfs_clean_segments() call. Reported-by: Sergey Alexandrov Signed-off-by: Vyacheslav Dubeyko Tested-by: Vyacheslav Dubeyko Acked-by: Ryusuke Konishi Tested-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

nilfs2: fix deadlock issue between chcp and thaw ioctls

2012-08-15T15:10:05Z

commit 572d8b3945a31bee7c40d21556803e4807fd9141 upstream. 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

nilfs2: avoid overflowing segment numbers in nilfs_ioctl_clean_segments()

2012-02-09T03:03:51Z

nsegs is read from userspace. Limit its value and avoid overflowing nsegs * sizeof(__u64) in the subsequent call to memdup_user(). This patch complements 481fe17e973fb9 ("nilfs2: potential integer overflow in nilfs_ioctl_clean_segments()"). Signed-off-by: Xi Wang Cc: Haogang Chen Acked-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

vfs: mnt_drop_write_file()

2012-01-04T03:52:40Z

new helper (wrapper around mnt_drop_write()) to be used in pair with mnt_want_write_file(). Signed-off-by: Al Viro

switch a bunch of places to mnt_want_write_file()

2012-01-04T03:52:35Z

it's both faster (in case when file has been opened for write) and cleaner. Signed-off-by: Al Viro

nilfs2: potential integer overflow in nilfs_ioctl_clean_segments()

2011-12-20T18:25:04Z

There is a potential integer overflow in nilfs_ioctl_clean_segments(). When a large argv[n].v_nmembs is passed from the userspace, the subsequent call to vmalloc() will allocate a buffer smaller than expected, which leads to out-of-bound access in nilfs_ioctl_move_blocks() and lfs_clean_segments(). The following check does not prevent the overflow because nsegs is also controlled by the userspace and could be very large. if (argv[n].v_nmembs > nsegs * nilfs->ns_blocks_per_segment) goto out_free; This patch clamps argv[n].v_nmembs to UINT_MAX / argv[n].v_size, and returns -EINVAL when overflow. Signed-off-by: Haogang Chen Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: unbreak compat ioctl

2011-12-20T18:25:04Z

commit 828b1c50ae ("nilfs2: add compat ioctl") incidentally broke all other NILFS compat ioctls. Make them work again. Signed-off-by: Thomas Meyer Signed-off-by: Ryusuke Konishi Tested-by: Ryusuke Konishi Cc: [3.0+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: implement resize ioctl

2011-05-10T13:21:46Z

This adds resize ioctl which makes online resize possible. Signed-off-by: Ryusuke Konishi

nilfs2: add ioctl which limits range of segment to be allocated

2011-05-10T13:21:45Z

This adds a new ioctl command which limits range of segment to be allocated. This is intended to gather data whithin a range of the partition before shrinking the filesystem, or to control new log location for some purpose. If a range is specified by the ioctl, segment allocator of nilfs tries to allocate new segments from the range unless no free segments are available there. Signed-off-by: Ryusuke Konishi

userns: rename is_owner_or_cap to inode_owner_or_capable

2011-03-24T02:47:13Z

And give it a kernel-doc comment. [akpm@linux-foundation.org: btrfs changed in linux-next] Signed-off-by: Serge E. Hallyn Cc: "Eric W. Biederman" Cc: Daniel Lezcano Acked-by: David Howells Cc: James Morris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds