* overlayfs: BUG in ovl_whiteout
@ 2010-10-01 18:07 Andy Whitcroft
2010-10-04 9:23 ` Miklos Szeredi
0 siblings, 1 reply; 6+ messages in thread
From: Andy Whitcroft @ 2010-10-01 18:07 UTC (permalink / raw)
To: Miklos Szeredi; +Cc: linux-fsdevel, linux-kernel, vaurora, neilb, viro
I have been playing with overlayfs for a bit now and there seems to
be something a little dodgy when unmounting and remounting an overlay.
I modified some files in the overlay, immediatly unmounted the overlay and
again immediatly remounted it. On touching the same files in the overlay
I triggered the following BUG (dmesg fragment at the bottom of this email).
When trying to reproduce this I also triggered a hard hang.
This is the specific BUG in my source:
static int ovl_whiteout(struct dentry *upperdir, struct dentry *dentry)
{
[...]
/* Just been removed within the same locked region */
BUG_ON(newdentry->d_inode);
[...]
}
All of this is against the V3 patches.
-apw
[ 3828.863867] ------------[ cut here ]------------
[ 3828.863898] kernel BUG at /home/apw/build/maverick/ubuntu-natty/fs/overlayfs/overlayfs.c:1441!
[ 3828.863940] invalid opcode: 0000 [#1] SMP
[ 3828.863965] last sysfs file: /sys/devices/pci0000:00/0000:00:1f.6/local_cpus
[ 3828.863998] CPU 1
[ 3828.864010] Modules linked in: overlayfs binfmt_misc ppdev kvm_intel kvm i915 drm_kms_helper snd_hda_codec_idt drm snd_hda_intel i2c_algo_bit snd_hda_codec video snd_hwdep tpm_tis tpm coretemp snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event output snd_seq tpm_bios intel_agp snd_timer lp snd_seq_device parport snd soundcore snd_page_alloc hid_belkin usbhid hid ahci e1000e libahci
[ 3828.864254]
[ 3828.864266] Pid: 18395, comm: apt-get Not tainted 2.6.36-0-generic #1~overlayfs201010011723 BB Name To be filled by O.E.M./Product Name To Be Filled By O.E.M.
[ 3828.864330] RIP: 0010:[<ffffffffa02ca173>] [<ffffffffa02ca173>] ovl_whiteout+0x113/0x120 [overlayfs]
[ 3828.864379] RSP: 0018:ffff8800670e1c28 EFLAGS: 00010282
[ 3828.864405] RAX: ffff8800263f3600 RBX: ffff88006711ec00 RCX: 0000000000000000
[ 3828.864439] RDX: ffff8800263f3600 RSI: ffff88006aefe4c2 RDI: ffff8800263f3608
[ 3828.864472] RBP: ffff8800670e1c58 R08: 0000000000000650 R09: ffff8800765d7e80
[ 3828.864506] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800263f3600
[ 3828.864539] R13: ffff88006e097240 R14: ffff880063881780 R15: 00000000fffffff4
[ 3828.864573] FS: 0000000000000000(0000) GS:ffff880001e80000(0063) knlGS:00000000f73d26d0
[ 3828.864612] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
[ 3828.864639] CR2: 00000000f770e4c0 CR3: 000000007808d000 CR4: 00000000000406e0
[ 3828.864673] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 3828.864706] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 3828.864740] Process apt-get (pid: 18395, threadinfo ffff8800670e0000, task ffff88006f4f2dc0)
[ 3828.864779] Stack:
[ 3828.864790] ffff8800670e1c58 ffff8800263bba80 ffff8800263bba80 0000000000000000
[ 3828.864832] <0> ffff8800263f3600 ffff880063881780 ffff8800670e1cf8 ffffffffa02cbbe9
[ 3828.864877] <0> ffff8800670e1d08 0000000000000001 ffff880063881701 ffff8800263f3600
[ 3828.864924] Call Trace:
[ 3828.864940] [<ffffffffa02cbbe9>] ovl_rename+0x319/0x3d0 [overlayfs]
[ 3828.864976] [<ffffffff8126af5f>] ? security_inode_permission+0x1f/0x30
[ 3828.865009] [<ffffffff81163db9>] ? dentry_permission+0x99/0xc0
[ 3828.865038] [<ffffffff81163a4b>] vfs_rename_other+0xcb/0x130
[ 3828.865067] [<ffffffff81164fdb>] vfs_rename+0x14b/0x240
[ 3828.865094] [<ffffffff81163555>] ? __lookup_hash+0x55/0xe0
[ 3828.865121] [<ffffffff8126af5f>] ? security_inode_permission+0x1f/0x30
[ 3828.865154] [<ffffffff81166d04>] sys_renameat+0x254/0x280
[ 3828.865184] [<ffffffff8159615e>] ? _raw_spin_lock+0xe/0x20
[ 3828.865212] [<ffffffff812c3bcd>] ? _atomic_dec_and_lock+0x4d/0x80
[ 3828.865243] [<ffffffff8159615e>] ? _raw_spin_lock+0xe/0x20
[ 3828.865271] [<ffffffff81157993>] ? sys_fchmodat+0x73/0x110
[ 3828.865300] [<ffffffff81048173>] ? sys32_stat64+0x33/0x40
[ 3828.865328] [<ffffffff81166d4b>] sys_rename+0x1b/0x20
[ 3828.865354] [<ffffffff81047230>] sysenter_dispatch+0x7/0x2e
[ 3828.865382] Code: eb d4 eb 04 90 90 90 90 48 8b 35 a1 2a 00 00 45 31 c0 b9 01 00 00 00 48 c7 c2 25 ce 2c a0 4c 89 e7 e8 92 fa ea e0 41 89 c7 eb 91 <0f> 0b eb fe 41 89 c7 eb 90 eb 02 90 90 55 48 89 e5 48 83 ec 20
[ 3828.865610] RIP [<ffffffffa02ca173>] ovl_whiteout+0x113/0x120 [overlayfs]
[ 3828.866873] RSP <ffff8800670e1c28>
[ 3828.889817] ---[ end trace ae40f79401a99f83 ]---
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: overlayfs: BUG in ovl_whiteout 2010-10-01 18:07 overlayfs: BUG in ovl_whiteout Andy Whitcroft @ 2010-10-04 9:23 ` Miklos Szeredi 2010-10-04 17:33 ` Andy Whitcroft 0 siblings, 1 reply; 6+ messages in thread From: Miklos Szeredi @ 2010-10-04 9:23 UTC (permalink / raw) To: Andy Whitcroft; +Cc: miklos, linux-fsdevel, linux-kernel On Fri, 1 Oct 2010, Andy Whitcroft wrote: > I have been playing with overlayfs for a bit now and there seems to > be something a little dodgy when unmounting and remounting an overlay. > I modified some files in the overlay, immediatly unmounted the overlay and > again immediatly remounted it. On touching the same files in the overlay > I triggered the following BUG (dmesg fragment at the bottom of this email). > When trying to reproduce this I also triggered a hard hang. Thanks for the bug report, Andy. Please change that BUG_ON to a WARN_ON. This will make this a harmless error message in the log instead of a hang. > > This is the specific BUG in my source: > > static int ovl_whiteout(struct dentry *upperdir, struct dentry *dentry) > { > [...] > /* Just been removed within the same locked region */ > BUG_ON(newdentry->d_inode); > [...] > } > > All of this is against the V3 patches. What are the filesystems used as the upper and lower layers of the overlay? Thanks, Miklos > > -apw > > [ 3828.863867] ------------[ cut here ]------------ > [ 3828.863898] kernel BUG at /home/apw/build/maverick/ubuntu-natty/fs/overlayfs/overlayfs.c:1441! > [ 3828.863940] invalid opcode: 0000 [#1] SMP > [ 3828.863965] last sysfs file: /sys/devices/pci0000:00/0000:00:1f.6/local_cpus > [ 3828.863998] CPU 1 > [ 3828.864010] Modules linked in: overlayfs binfmt_misc ppdev kvm_intel kvm i915 drm_kms_helper snd_hda_codec_idt drm snd_hda_intel i2c_algo_bit snd_hda_codec video snd_hwdep tpm_tis tpm coretemp snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event output snd_seq tpm_bios intel_agp snd_timer lp snd_seq_device parport snd soundcore snd_page_alloc hid_belkin usbhid hid ahci e1000e libahci > [ 3828.864254] > [ 3828.864266] Pid: 18395, comm: apt-get Not tainted 2.6.36-0-generic #1~overlayfs201010011723 BB Name To be filled by O.E.M./Product Name To Be Filled By O.E.M. > [ 3828.864330] RIP: 0010:[<ffffffffa02ca173>] [<ffffffffa02ca173>] ovl_whiteout+0x113/0x120 [overlayfs] > [ 3828.864379] RSP: 0018:ffff8800670e1c28 EFLAGS: 00010282 > [ 3828.864405] RAX: ffff8800263f3600 RBX: ffff88006711ec00 RCX: 0000000000000000 > [ 3828.864439] RDX: ffff8800263f3600 RSI: ffff88006aefe4c2 RDI: ffff8800263f3608 > [ 3828.864472] RBP: ffff8800670e1c58 R08: 0000000000000650 R09: ffff8800765d7e80 > [ 3828.864506] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800263f3600 > [ 3828.864539] R13: ffff88006e097240 R14: ffff880063881780 R15: 00000000fffffff4 > [ 3828.864573] FS: 0000000000000000(0000) GS:ffff880001e80000(0063) knlGS:00000000f73d26d0 > [ 3828.864612] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 > [ 3828.864639] CR2: 00000000f770e4c0 CR3: 000000007808d000 CR4: 00000000000406e0 > [ 3828.864673] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 3828.864706] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > [ 3828.864740] Process apt-get (pid: 18395, threadinfo ffff8800670e0000, task ffff88006f4f2dc0) > [ 3828.864779] Stack: > [ 3828.864790] ffff8800670e1c58 ffff8800263bba80 ffff8800263bba80 0000000000000000 > [ 3828.864832] <0> ffff8800263f3600 ffff880063881780 ffff8800670e1cf8 ffffffffa02cbbe9 > [ 3828.864877] <0> ffff8800670e1d08 0000000000000001 ffff880063881701 ffff8800263f3600 > [ 3828.864924] Call Trace: > [ 3828.864940] [<ffffffffa02cbbe9>] ovl_rename+0x319/0x3d0 [overlayfs] > [ 3828.864976] [<ffffffff8126af5f>] ? security_inode_permission+0x1f/0x30 > [ 3828.865009] [<ffffffff81163db9>] ? dentry_permission+0x99/0xc0 > [ 3828.865038] [<ffffffff81163a4b>] vfs_rename_other+0xcb/0x130 > [ 3828.865067] [<ffffffff81164fdb>] vfs_rename+0x14b/0x240 > [ 3828.865094] [<ffffffff81163555>] ? __lookup_hash+0x55/0xe0 > [ 3828.865121] [<ffffffff8126af5f>] ? security_inode_permission+0x1f/0x30 > [ 3828.865154] [<ffffffff81166d04>] sys_renameat+0x254/0x280 > [ 3828.865184] [<ffffffff8159615e>] ? _raw_spin_lock+0xe/0x20 > [ 3828.865212] [<ffffffff812c3bcd>] ? _atomic_dec_and_lock+0x4d/0x80 > [ 3828.865243] [<ffffffff8159615e>] ? _raw_spin_lock+0xe/0x20 > [ 3828.865271] [<ffffffff81157993>] ? sys_fchmodat+0x73/0x110 > [ 3828.865300] [<ffffffff81048173>] ? sys32_stat64+0x33/0x40 > [ 3828.865328] [<ffffffff81166d4b>] sys_rename+0x1b/0x20 > [ 3828.865354] [<ffffffff81047230>] sysenter_dispatch+0x7/0x2e > [ 3828.865382] Code: eb d4 eb 04 90 90 90 90 48 8b 35 a1 2a 00 00 45 31 c0 b9 01 00 00 00 48 c7 c2 25 ce 2c a0 4c 89 e7 e8 92 fa ea e0 41 89 c7 eb 91 <0f> 0b eb fe 41 89 c7 eb 90 eb 02 90 90 55 48 89 e5 48 83 ec 20 > [ 3828.865610] RIP [<ffffffffa02ca173>] ovl_whiteout+0x113/0x120 [overlayfs] > [ 3828.866873] RSP <ffff8800670e1c28> > [ 3828.889817] ---[ end trace ae40f79401a99f83 ]--- > > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: overlayfs: BUG in ovl_whiteout 2010-10-04 9:23 ` Miklos Szeredi @ 2010-10-04 17:33 ` Andy Whitcroft 2010-10-04 20:16 ` Miklos Szeredi 0 siblings, 1 reply; 6+ messages in thread From: Andy Whitcroft @ 2010-10-04 17:33 UTC (permalink / raw) To: Miklos Szeredi; +Cc: linux-fsdevel, linux-kernel On Mon, Oct 04, 2010 at 11:23:16AM +0200, Miklos Szeredi wrote: > On Fri, 1 Oct 2010, Andy Whitcroft wrote: > > I have been playing with overlayfs for a bit now and there seems to > > be something a little dodgy when unmounting and remounting an overlay. > > I modified some files in the overlay, immediatly unmounted the overlay and > > again immediatly remounted it. On touching the same files in the overlay > > I triggered the following BUG (dmesg fragment at the bottom of this email). > > When trying to reproduce this I also triggered a hard hang. > > Thanks for the bug report, Andy. > > Please change that BUG_ON to a WARN_ON. This will make this a > harmless error message in the log instead of a hang. Applied your patch to move these to WARN_ON. Now I get a WARN_ON after the remount. Now that we don't explode I get the following error from the triggering command. I assume that this is the rename which has triggered the issue: W: Failed to fetch http://192.168.0.60:3142/archive.ubuntu.com/ubuntu/dists/maverick/Release rename failed, File exists (/var/lib/apt/lists/192.168.0.60:3142_archive.ubuntu.com_ubuntu_dists_maverick_Release -> /var/lib/apt/lists/192.168.0.60:3142_archive.ubuntu.com_ubuntu_dists_maverick_Release). I note that the file does indeed exist as a real file in both layers. I have not as yet managed to generate a naive test that also triggers this. -apw ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: overlayfs: BUG in ovl_whiteout 2010-10-04 17:33 ` Andy Whitcroft @ 2010-10-04 20:16 ` Miklos Szeredi 2010-10-06 12:29 ` Andy Whitcroft 0 siblings, 1 reply; 6+ messages in thread From: Miklos Szeredi @ 2010-10-04 20:16 UTC (permalink / raw) To: Andy Whitcroft; +Cc: miklos, linux-fsdevel, linux-kernel On Mon, 4 Oct 2010, Andy Whitcroft wrote: > On Mon, Oct 04, 2010 at 11:23:16AM +0200, Miklos Szeredi wrote: > > On Fri, 1 Oct 2010, Andy Whitcroft wrote: > > > I have been playing with overlayfs for a bit now and there seems to > > > be something a little dodgy when unmounting and remounting an overlay. > > > I modified some files in the overlay, immediatly unmounted the overlay and > > > again immediatly remounted it. On touching the same files in the overlay > > > I triggered the following BUG (dmesg fragment at the bottom of this email). > > > When trying to reproduce this I also triggered a hard hang. > > > > Thanks for the bug report, Andy. > > > > Please change that BUG_ON to a WARN_ON. This will make this a > > harmless error message in the log instead of a hang. > > Applied your patch to move these to WARN_ON. Now I get a WARN_ON after > the remount. Now that we don't explode I get the following error from > the triggering command. I assume that this is the rename which has > triggered the issue: > > W: Failed to fetch http://192.168.0.60:3142/archive.ubuntu.com/ubuntu/dists/maverick/Release rename failed, File exists (/var/lib/apt/lists/192.168.0.60:3142_archive.ubuntu.com_ubuntu_dists_maverick_Release -> /var/lib/apt/lists/192.168.0.60:3142_archive.ubuntu.com_ubuntu_dists_maverick_Release). > > I note that the file does indeed exist as a real file in both layers. I > have not as yet managed to generate a naive test that also triggers > this. OK, my guess is that it's a 'rename to self' which was not properly implemented. Does the following patch make a difference? Thanks, Miklos --- fs/namei.c | 19 ++++++++++++++----- fs/overlayfs/overlayfs.c | 19 ++++++++++++++++++- include/linux/fs.h | 3 ++- 3 files changed, 34 insertions(+), 7 deletions(-) Index: linux-2.6/fs/namei.c =================================================================== --- linux-2.6.orig/fs/namei.c 2010-10-04 19:40:20.000000000 +0200 +++ linux-2.6/fs/namei.c 2010-10-04 21:46:13.000000000 +0200 @@ -2620,6 +2620,17 @@ static int vfs_rename_other(struct inode return error; } +bool vfs_is_same_inode(struct dentry *d1, struct dentry *d2) +{ + BUG_ON(d1->d_sb != d2->d_sb); + + if (d1->d_sb->s_op->is_same_inode) + return d1->d_sb->s_op->is_same_inode(d1, d2); + else + return d1->d_inode == d2->d_inode; +} +EXPORT_SYMBOL(vfs_is_same_inode); + int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { @@ -2627,11 +2638,9 @@ int vfs_rename(struct inode *old_dir, st int is_dir = S_ISDIR(old_dentry->d_inode->i_mode); const unsigned char *old_name; - if (old_dentry->d_inode == new_dentry->d_inode && - !(old_dir->i_sb->s_type->fs_flags & FS_RENAME_SELF_ALLOW)) { - return 0; - } - + if (vfs_is_same_inode(old_dentry, new_dentry)) + return 0; + error = may_delete(old_dir, old_dentry, is_dir); if (error) return error; Index: linux-2.6/fs/overlayfs/overlayfs.c =================================================================== --- linux-2.6.orig/fs/overlayfs/overlayfs.c 2010-10-04 19:40:20.000000000 +0200 +++ linux-2.6/fs/overlayfs/overlayfs.c 2010-10-04 21:00:05.000000000 +0200 @@ -1962,10 +1962,28 @@ static int ovl_statfs(struct dentry *den return path.dentry->d_sb->s_op->statfs(path.dentry, buf); } +static bool ovl_is_same_inode(struct dentry *d1, struct dentry *d2) +{ + struct dentry *upperd1; + struct dentry *upperd2; + + upperd1 = ovl_dentry_upper(d1); + upperd2 = ovl_dentry_upper(d2); + + if (upperd1 && upperd2) + return vfs_is_same_inode(upperd1, upperd2); + + if (upperd1 || upperd2) + return false; + + return vfs_is_same_inode(ovl_dentry_lower(d1), ovl_dentry_lower(d2)); +} + static const struct super_operations ovl_super_operations = { .put_super = ovl_put_super, .remount_fs = ovl_remount_fs, .statfs = ovl_statfs, + .is_same_inode = ovl_is_same_inode, }; struct ovl_config { @@ -2155,7 +2173,6 @@ static int ovl_get_sb(struct file_system static struct file_system_type ovl_fs_type = { .owner = THIS_MODULE, .name = "overlayfs", - .fs_flags = FS_RENAME_SELF_ALLOW, .get_sb = ovl_get_sb, .kill_sb = kill_anon_super, }; Index: linux-2.6/include/linux/fs.h =================================================================== --- linux-2.6.orig/include/linux/fs.h 2010-10-04 19:40:20.000000000 +0200 +++ linux-2.6/include/linux/fs.h 2010-10-04 21:47:40.000000000 +0200 @@ -179,7 +179,6 @@ struct inodes_stat_t { #define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() * during rename() internally. */ -#define FS_RENAME_SELF_ALLOW 65536 /* Allow rename to same inode */ /* * These are the fs-independent mount-flags: up to 32 flags are supported @@ -1579,6 +1578,7 @@ struct super_operations { ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); #endif int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t); + bool (*is_same_inode)(struct dentry *, struct dentry *); }; /* @@ -1816,6 +1816,7 @@ extern int vfs_statfs(struct path *, str extern int statfs_by_dentry(struct dentry *, struct kstatfs *); extern int freeze_super(struct super_block *super); extern int thaw_super(struct super_block *super); +extern bool vfs_is_same_inode(struct dentry *d1, struct dentry *d2); extern int current_umask(void); ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: overlayfs: BUG in ovl_whiteout 2010-10-04 20:16 ` Miklos Szeredi @ 2010-10-06 12:29 ` Andy Whitcroft 2010-10-06 16:51 ` Miklos Szeredi 0 siblings, 1 reply; 6+ messages in thread From: Andy Whitcroft @ 2010-10-06 12:29 UTC (permalink / raw) To: Miklos Szeredi; +Cc: linux-fsdevel, linux-kernel On Mon, Oct 04, 2010 at 10:16:29PM +0200, Miklos Szeredi wrote: > > OK, my guess is that it's a 'rename to self' which was not properly > implemented. > > Does the following patch make a difference? That one panic'd immediatly. Seems that we can have missmatched lowers as well. I applied the below over the top, and that seems to pass testing without tripping the WARN_ON. -apw commit 03375858c62f617846b5dc4968fe8178eda51a7c Author: Andy Whitcroft <apw@canonical.com> Date: Tue Oct 5 14:54:08 2010 +0100 overlayfs: handle missing lower inodes in ovl_is_same_inode Signed-off-by: Andy Whitcroft <apw@canonical.com> diff --git a/fs/overlayfs/overlayfs.c b/fs/overlayfs/overlayfs.c index c10cc7b..f596222 100644 --- a/fs/overlayfs/overlayfs.c +++ b/fs/overlayfs/overlayfs.c @@ -1964,19 +1964,25 @@ static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf) static bool ovl_is_same_inode(struct dentry *d1, struct dentry *d2) { - struct dentry *upperd1; - struct dentry *upperd2; + struct dentry *od1; + struct dentry *od2; - upperd1 = ovl_dentry_upper(d1); - upperd2 = ovl_dentry_upper(d2); + od1 = ovl_dentry_upper(d1); + od2 = ovl_dentry_upper(d2); - if (upperd1 && upperd2) - return vfs_is_same_inode(upperd1, upperd2); + if (od1 && od2) + return vfs_is_same_inode(od1, od2); - if (upperd1 || upperd2) + if (od1 || od2) return false; - return vfs_is_same_inode(ovl_dentry_lower(d1), ovl_dentry_lower(d2)); + od1 = ovl_dentry_lower(d1); + od2 = ovl_dentry_lower(d2); + + if (od1 && od2) + return vfs_is_same_inode(od1, od2); + + return false; } static const struct super_operations ovl_super_operations = { ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: overlayfs: BUG in ovl_whiteout 2010-10-06 12:29 ` Andy Whitcroft @ 2010-10-06 16:51 ` Miklos Szeredi 0 siblings, 0 replies; 6+ messages in thread From: Miklos Szeredi @ 2010-10-06 16:51 UTC (permalink / raw) To: Andy Whitcroft; +Cc: miklos, linux-fsdevel, linux-kernel On Wed, 6 Oct 2010, Andy Whitcroft wrote: > On Mon, Oct 04, 2010 at 10:16:29PM +0200, Miklos Szeredi wrote: > > > > OK, my guess is that it's a 'rename to self' which was not properly > > implemented. > > > > Does the following patch make a difference? > > That one panic'd immediatly. Seems that we can have missmatched lowers > as well. I applied the below over the top, and that seems to pass > testing without tripping the WARN_ON. > > -apw > > commit 03375858c62f617846b5dc4968fe8178eda51a7c > Author: Andy Whitcroft <apw@canonical.com> > Date: Tue Oct 5 14:54:08 2010 +0100 > > overlayfs: handle missing lower inodes in ovl_is_same_inode > > Signed-off-by: Andy Whitcroft <apw@canonical.com> OK, that's because d1 or d2 is negative, otherwise either the upper or the lower dentry _must_ exist. In the version I committed to the overlayfs.v3 branch vfs_is_same_inode() checks whether the dentries are positive and only calls ->is_same_inode() if they are. Can you please try pull from that branch and check if it's still buggy without your patch? Thanks, Miklos > > diff --git a/fs/overlayfs/overlayfs.c b/fs/overlayfs/overlayfs.c > index c10cc7b..f596222 100644 > --- a/fs/overlayfs/overlayfs.c > +++ b/fs/overlayfs/overlayfs.c > @@ -1964,19 +1964,25 @@ static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf) > > static bool ovl_is_same_inode(struct dentry *d1, struct dentry *d2) > { > - struct dentry *upperd1; > - struct dentry *upperd2; > + struct dentry *od1; > + struct dentry *od2; > > - upperd1 = ovl_dentry_upper(d1); > - upperd2 = ovl_dentry_upper(d2); > + od1 = ovl_dentry_upper(d1); > + od2 = ovl_dentry_upper(d2); > > - if (upperd1 && upperd2) > - return vfs_is_same_inode(upperd1, upperd2); > + if (od1 && od2) > + return vfs_is_same_inode(od1, od2); > > - if (upperd1 || upperd2) > + if (od1 || od2) > return false; > > - return vfs_is_same_inode(ovl_dentry_lower(d1), ovl_dentry_lower(d2)); > + od1 = ovl_dentry_lower(d1); > + od2 = ovl_dentry_lower(d2); > + > + if (od1 && od2) > + return vfs_is_same_inode(od1, od2); > + > + return false; > } > > static const struct super_operations ovl_super_operations = { > ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2010-10-06 16:51 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2010-10-01 18:07 overlayfs: BUG in ovl_whiteout Andy Whitcroft 2010-10-04 9:23 ` Miklos Szeredi 2010-10-04 17:33 ` Andy Whitcroft 2010-10-04 20:16 ` Miklos Szeredi 2010-10-06 12:29 ` Andy Whitcroft 2010-10-06 16:51 ` Miklos Szeredi
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