- 20 4月, 2018 1 次提交
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由 Al Viro 提交于
We want it only for the stuff created by SB_KERNMOUNT mounts, *not* for their copies. As it is, creating a deep stack of bindings of /proc/*/ns/* somewhere in a new namespace and exiting yields a stack overflow. Cc: stable@kernel.org Reported-by: NAlexander Aring <aring@mojatatu.com> Bisected-by: NKirill Tkhai <ktkhai@virtuozzo.com> Tested-by: NKirill Tkhai <ktkhai@virtuozzo.com> Tested-by: NAlexander Aring <aring@mojatatu.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 16 4月, 2018 3 次提交
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由 Tetsuo Handa 提交于
syzbot is catching so many bugs triggered by commit 9ee332d9 ("sget(): handle failures of register_shrinker()"). That commit expected that calling kill_sb() from deactivate_locked_super() without successful fill_super() is safe, but the reality was different; some callers assign attributes which are needed for kill_sb() after sget() succeeds. For example, [1] is a report where sb->s_mode (which seems to be either FMODE_READ | FMODE_EXCL | FMODE_WRITE or FMODE_READ | FMODE_EXCL) is not assigned unless sget() succeeds. But it does not worth complicate sget() so that register_shrinker() failure path can safely call kill_block_super() via kill_sb(). Making alloc_super() fail if memory allocation for register_shrinker() failed is much simpler. Let's avoid calling deactivate_locked_super() from sget_userns() by preallocating memory for the shrinker and making register_shrinker() in sget_userns() never fail. [1] https://syzkaller.appspot.com/bug?id=588996a25a2587be2e3a54e8646728fb9cae44e7Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: Nsyzbot <syzbot+5a170e19c963a2e0df79@syzkaller.appspotmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
orangefs_fill_sb() might've failed to allocate ORANGEFS_SB(s); don't oops in that case. Cc: stable@kernel.org Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
jffs2_fill_super() might fail to allocate jffs2_sb_info; jffs2_kill_sb() must survive that. Cc: stable@kernel.org Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 14 4月, 2018 1 次提交
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由 Alexey Dobriyan 提交于
If module removes proc directory while another process pins it by chdir'ing to it, then subsequent recreation of proc entry and all entries down the tree will not be visible to any process until pinning process unchdir from directory and unpins everything. Steps to reproduce: proc_mkdir("aaa", NULL); proc_create("aaa/bbb", ...); chdir("/proc/aaa"); remove_proc_entry("aaa/bbb", NULL); remove_proc_entry("aaa", NULL); proc_mkdir("aaa", NULL); # inaccessible because "aaa" dentry still points # to the original "aaa". proc_create("aaa/bbb", ...); Fix is to implement ->d_revalidate and ->d_delete. Link: http://lkml.kernel.org/r/20180312201938.GA4871@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 13 4月, 2018 12 次提交
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由 Qu Wenruo 提交于
When looping btrfs/074 with many cpus (>= 8), it's possible to trigger kernel warning due to first key verification: [ 4239.523446] WARNING: CPU: 5 PID: 2381 at fs/btrfs/disk-io.c:460 btree_read_extent_buffer_pages+0x1ad/0x210 [ 4239.523830] Modules linked in: [ 4239.524630] RIP: 0010:btree_read_extent_buffer_pages+0x1ad/0x210 [ 4239.527101] Call Trace: [ 4239.527251] read_tree_block+0x42/0x70 [ 4239.527434] read_node_slot+0xd2/0x110 [ 4239.527632] push_leaf_right+0xad/0x1b0 [ 4239.527809] split_leaf+0x4ea/0x700 [ 4239.527988] ? leaf_space_used+0xbc/0xe0 [ 4239.528192] ? btrfs_set_lock_blocking_rw+0x99/0xb0 [ 4239.528416] btrfs_search_slot+0x8cc/0xa40 [ 4239.528605] btrfs_insert_empty_items+0x71/0xc0 [ 4239.528798] __btrfs_run_delayed_refs+0xa98/0x1680 [ 4239.529013] btrfs_run_delayed_refs+0x10b/0x1b0 [ 4239.529205] btrfs_commit_transaction+0x33/0xaf0 [ 4239.529445] ? start_transaction+0xa8/0x4f0 [ 4239.529630] btrfs_alloc_data_chunk_ondemand+0x1b0/0x4e0 [ 4239.529833] btrfs_check_data_free_space+0x54/0xa0 [ 4239.530045] btrfs_delalloc_reserve_space+0x25/0x70 [ 4239.531907] btrfs_direct_IO+0x233/0x3d0 [ 4239.532098] generic_file_direct_write+0xcb/0x170 [ 4239.532296] btrfs_file_write_iter+0x2bb/0x5f4 [ 4239.532491] aio_write+0xe2/0x180 [ 4239.532669] ? lock_acquire+0xac/0x1e0 [ 4239.532839] ? __might_fault+0x3e/0x90 [ 4239.533032] do_io_submit+0x594/0x860 [ 4239.533223] ? do_io_submit+0x594/0x860 [ 4239.533398] SyS_io_submit+0x10/0x20 [ 4239.533560] ? SyS_io_submit+0x10/0x20 [ 4239.533729] do_syscall_64+0x75/0x1d0 [ 4239.533979] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 4239.534182] RIP: 0033:0x7f8519741697 The problem here is, at btree_read_extent_buffer_pages() we don't have acquired read/write lock on that extent buffer, only basic info like level/bytenr is reliable. So race condition leads to such false alert. However in current call site, it's impossible to acquire proper lock without race window. To fix the problem, we only verify first key for committed tree blocks (whose generation is no larger than fs_info->last_trans_committed), so the content of such tree blocks will not change and there is no need to get read/write lock. Reported-by: NNikolay Borisov <nborisov@suse.com> Fixes: 581c1760 ("btrfs: Validate child tree block's level and first key") Signed-off-by: NQu Wenruo <wqu@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Ronnie Sahlberg 提交于
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com> Signed-off-by: NSteve French <smfrench@gmail.com> Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
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由 Ronnie Sahlberg 提交于
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com> Signed-off-by: NSteve French <smfrench@gmail.com> Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
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由 Ronnie Sahlberg 提交于
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com> Signed-off-by: NSteve French <smfrench@gmail.com> Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
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由 Ronnie Sahlberg 提交于
and get rid of some more calls to get_rfc1002_length() Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com> Signed-off-by: NSteve French <smfrench@gmail.com> Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
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由 Steve French 提交于
More cleanup of use of hardcoded 4 byte RFC1001 field size Signed-off-by: NSteve French <smfrench@gmail.com> Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com> Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>
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由 Ronnie Sahlberg 提交于
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com> Signed-off-by: NSteve French <smfrench@gmail.com> Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
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由 Ronnie Sahlberg 提交于
and get rid of some get_rfc1002_length() in smb2 Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com> Signed-off-by: NSteve French <smfrench@gmail.com> Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
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由 Steve French 提交于
SMB3.11 crypto and hash contexts were not being checked strictly enough. Add parsing and validity checking for the security contexts in the SMB3.11 negotiate response. Signed-off-by: NSteve French <smfrench@gmail.com> CC: Stable <stable@vger.kernel.org> Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
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由 Steve French 提交于
The length checking for SMB3.11 negotiate request includes "negotiate contexts" which caused a buffer validation problem and a confusing warning message on SMB3.11 mount e.g.: SMB2 server sent bad RFC1001 len 236 not 170 Fix the length checking for SMB3.11 negotiate to account for the new negotiate context so that we don't log a warning on SMB3.11 mount by default but do log warnings if lengths returned by the server are incorrect. CC: Stable <stable@vger.kernel.org> Signed-off-by: NSteve French <smfrench@gmail.com> Reviewed-by: NAurelien Aptel <aaptel@suse.com> Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
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由 Bob Peterson 提交于
This patch simply fixes some comments and the gfs2-glocks.txt file: Places where i_rwsem was called i_mutex, and adding i_rw_mutex. Signed-off-by: NBob Peterson <rpeterso@redhat.com>
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由 Andreas Gruenbacher 提交于
Function rhashtable_walk_peek is problematic because there is no guarantee that the glock previously returned still exists; when that key is deleted, rhashtable_walk_peek can end up returning a different key, which will cause an inconsistent glock dump. Fix this by keeping track of the current glock in the seq file iterator functions instead. Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com> Signed-off-by: NBob Peterson <rpeterso@redhat.com>
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- 12 4月, 2018 23 次提交
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由 David Sterba 提交于
Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 David Sterba 提交于
Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 David Sterba 提交于
Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Unify the include protection macros to match the file names. Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Filipe Manana 提交于
Currently if we allocate extents beyond an inode's i_size (through the fallocate system call) and then fsync the file, we log the extents but after a power failure we replay them and then immediately drop them. This behaviour happens since about 2009, commit c71bf099 ("Btrfs: Avoid orphan inodes cleanup while replaying log"), because it marks the inode as an orphan instead of dropping any extents beyond i_size before replaying logged extents, so after the log replay, and while the mount operation is still ongoing, we find the inode marked as an orphan and then perform a truncation (drop extents beyond the inode's i_size). Because the processing of orphan inodes is still done right after replaying the log and before the mount operation finishes, the intention of that commit does not make any sense (at least as of today). However reverting that behaviour is not enough, because we can not simply discard all extents beyond i_size and then replay logged extents, because we risk dropping extents beyond i_size created in past transactions, for example: add prealloc extent beyond i_size fsync - clears the flag BTRFS_INODE_NEEDS_FULL_SYNC from the inode transaction commit add another prealloc extent beyond i_size fsync - triggers the fast fsync path power failure In that scenario, we would drop the first extent and then replay the second one. To fix this just make sure that all prealloc extents beyond i_size are logged, and if we find too many (which is far from a common case), fallback to a full transaction commit (like we do when logging regular extents in the fast fsync path). Trivial reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "pwrite -S 0xab 0 256K" /mnt/foo $ sync $ xfs_io -c "falloc -k 256K 1M" /mnt/foo $ xfs_io -c "fsync" /mnt/foo <power failure> # mount to replay log $ mount /dev/sdb /mnt # at this point the file only has one extent, at offset 0, size 256K A test case for fstests follows soon, covering multiple scenarios that involve adding prealloc extents with previous shrinking truncates and without such truncates. Fixes: c71bf099 ("Btrfs: Avoid orphan inodes cleanup while replaying log") Signed-off-by: NFilipe Manana <fdmanana@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Liu Bo 提交于
Currently if some fatal errors occur, like all IO get -EIO, resources would be cleaned up when a) transaction is being committed or b) BTRFS_FS_STATE_ERROR is set However, in some rare cases, resources may be left alone after transaction gets aborted and umount may run into some ASSERT(), e.g. ASSERT(list_empty(&block_group->dirty_list)); For case a), in btrfs_commit_transaciton(), there're several places at the beginning where we just call btrfs_end_transaction() without cleaning up resources. For case b), it is possible that the trans handle doesn't have any dirty stuff, then only trans hanlde is marked as aborted while BTRFS_FS_STATE_ERROR is not set, so resources remain in memory. This makes btrfs also check BTRFS_FS_STATE_TRANS_ABORTED to make sure that all resources won't stay in memory after umount. Signed-off-by: NLiu Bo <bo.liu@linux.alibaba.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Amir Goldstein 提交于
With mount option "xino=on", mounter declares that there are enough free high bits in underlying fs to hold the layer fsid. If overlayfs does encounter underlying inodes using the high xino bits reserved for layer fsid, a warning will be emitted and the original inode number will be used. The mount option name "xino" goes after a similar meaning mount option of aufs, but in overlayfs case, the mapping is stateless. An example for a use case of "xino=on" is when upper/lower is on an xfs filesystem. xfs uses 64bit inode numbers, but it currently never uses the upper 8bit for inode numbers exposed via stat(2) and that is not likely to change in the future without user opting-in for a new xfs feature. The actual number of unused upper bit is much larger and determined by the xfs filesystem geometry (64 - agno_log - agblklog - inopblog). That means that for all practical purpose, there are enough unused bits in xfs inode numbers for more than OVL_MAX_STACK unique fsid's. Another use case of "xino=on" is when upper/lower is on tmpfs. tmpfs inode numbers are allocated sequentially since boot, so they will practially never use the high inode number bits. For compatibility with applications that expect 32bit inodes, the feature can be disabled with "xino=off". The option "xino=auto" automatically detects underlying filesystem that use 32bit inodes and enables the feature. The Kconfig option OVERLAY_FS_XINO_AUTO and module parameter of the same name, determine if the default mode for overlayfs mount is "xino=auto" or "xino=off". Signed-off-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Amir Goldstein 提交于
When overlay layers are not all on the same fs, but all inode numbers of underlying fs do not use the high 'xino' bits, overlay st_ino values are constant and persistent. In that case, relax non-samefs constraint for consistent d_ino and always iterate non-merge dir using ovl_fill_real() actor so we can remap lower inode numbers to unique lower fs range. Signed-off-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Amir Goldstein 提交于
When overlay layers are not all on the same fs, but all inode numbers of underlying fs do not use the high 'xino' bits, overlay st_ino values are constant and persistent. In that case, set i_ino value to the same value as st_ino for nfsd readdirplus validator. Signed-off-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Amir Goldstein 提交于
On 64bit systems, when overlay layers are not all on the same fs, but all inode numbers of underlying fs are not using the high bits, use the high bits to partition the overlay st_ino address space. The high bits hold the fsid (upper fsid is 0). This way overlay inode numbers are unique and all inodes use overlay st_dev. Inode numbers are also persistent for a given layer configuration. Currently, our only indication for available high ino bits is from a filesystem that supports file handles and uses the default encode_fh() operation, which encodes a 32bit inode number. Signed-off-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Amir Goldstein 提交于
Instead of allocating an anonymous bdev per lower layer, allocate one anonymous bdev per every unique lower fs that is different than upper fs. Every unique lower fs is assigned an fsid > 0 and the number of unique lower fs are stored in ofs->numlowerfs. The assigned fsid is stored in the lower layer struct and will be used also for inode number multiplexing. Signed-off-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Amir Goldstein 提交于
A helper for ovl_getattr() to map the values of st_dev and st_ino according to constant st_ino rules. Signed-off-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Miklos Szeredi 提交于
No need to mess with an alias, the upperdentry can be retrieved directly from the overlay inode. Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Miklos Szeredi 提交于
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Vivek Goyal 提交于
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Vivek Goyal 提交于
Certain properties in ovl_lookup_data should be set only for the last element of the path. IOW, if we are calling ovl_lookup_single() for an absolute redirect, then d->is_dir and d->opaque do not make much sense for intermediate path elements. Instead set them only if dentry being lookup is last path element. As of now we do not seem to be making use of d->opaque if it is set for a path/dentry in lower. But just define the semantics so that future code can make use of this assumption. Signed-off-by: NVivek Goyal <vgoyal@redhat.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Vivek Goyal 提交于
If we are looking in last layer, then there should not be any need to process redirect. redirect information is used only for lookup in next lower layer and there is no more lower layer to look into. So no need to process redirects. IOW, ignore redirects on lowest layer. Signed-off-by: NVivek Goyal <vgoyal@redhat.com> Reviewed-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Amir Goldstein 提交于
When decoding a lower file handle, we need to check if lower file was copied up and indexed and if it has a whiteout index, we need to check if this is an unlinked but open non-dir before returning -ESTALE. To find out if this is an unlinked but open non-dir we need to lookup an overlay inode in inode cache by lower inode and that requires decoding the lower file handle before looking in inode cache. Before this change, if the lower inode turned out to be a directory, we may have paid an expensive cost to reconnect that lower directory for nothing. After this change, we start by decoding a disconnected lower dentry and using the lower inode for looking up an overlay inode in inode cache. If we find overlay inode and dentry in cache, we avoid the index lookup overhead. If we don't find an overlay inode and dentry in cache, then we only need to decode a connected lower dentry in case the lower dentry is a non-indexed directory. The xfstests group overlay/exportfs tests decoding overlayfs file handles after drop_caches with different states of the file at encode and decode time. Overall the tests in the group call ovl_lower_fh_to_d() 89 times to decode a lower file handle. Before this change, the tests called ovl_get_index_fh() 75 times and reconnect_one() 61 times. After this change, the tests call ovl_get_index_fh() 70 times and reconnect_one() 59 times. The 2 cases where reconnect_one() was avoided are cases where a non-upper directory file handle was encoded, then the directory removed and then file handle was decoded. To demonstrate the affect on decoding file handles with hot inode/dentry cache, the drop_caches call in the tests was disabled. Without drop_caches, there are no reconnect_one() calls at all before or after the change. Before the change, there are 75 calls to ovl_get_index_fh(), exactly as the case with drop_caches. After the change, there are only 10 calls to ovl_get_index_fh(). Signed-off-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Amir Goldstein 提交于
On lookup of non directory, we try to decode the origin file handle stored in upper inode. The origin file handle is supposed to be decoded to a disconnected non-dir dentry, which is fine, because we only need the lower inode of a copy up origin. However, if the origin file handle somehow turns out to be a directory we pay the expensive cost of reconnecting the directory dentry, only to get a mismatch file type and drop the dentry. Optimize this case by explicitly opting out of reconnecting the dentry. Opting-out of reconnect is done by passing a NULL acceptable callback to exportfs_decode_fh(). While the case described above is a strange corner case that does not really need to be optimized, the API added for this optimization will be used by a following patch to optimize a more common case of decoding an overlayfs file handle. Signed-off-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Amir Goldstein 提交于
Rename ovl_encode_fh() to ovl_encode_real_fh() to differentiate from the exportfs function ovl_encode_inode_fh() and change the latter to ovl_encode_fh() to match the exportfs method name. Rename ovl_decode_fh() to ovl_decode_real_fh() for consistency. Signed-off-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Amir Goldstein 提交于
For broken hardlinks, we do not return lower st_ino, so we should also not return lower pseudo st_dev. Fixes: a0c5ad30 ("ovl: relax same fs constraint for constant st_ino") Cc: <stable@vger.kernel.org> #v4.15 Signed-off-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Amir Goldstein 提交于
As of now if we encounter an opaque dir while looking for a dentry, we set d->last=true. This means that there is no need to look further in any of the lower layers. This works fine as long as there are no redirets or relative redircts. But what if there is an absolute redirect on the children dentry of opaque directory. We still need to continue to look into next lower layer. This patch fixes it. Here is an example to demonstrate the issue. Say you have following setup. upper: /redirect (redirect=/a/b/c) lower1: /a/[b]/c ([b] is opaque) (c has absolute redirect=/a/b/d/) lower0: /a/b/d/foo Now "redirect" dir should merge with lower1:/a/b/c/ and lower0:/a/b/d. Note, despite the fact lower1:/a/[b] is opaque, we need to continue to look into lower0 because children c has an absolute redirect. Following is a reproducer. Watch me make foo disappear: $ mkdir lower middle upper work work2 merged $ mkdir lower/origin $ touch lower/origin/foo $ mount -t overlay none merged/ \ -olowerdir=lower,upperdir=middle,workdir=work2 $ mkdir merged/pure $ mv merged/origin merged/pure/redirect $ umount merged $ mount -t overlay none merged/ \ -olowerdir=middle:lower,upperdir=upper,workdir=work $ mv merged/pure/redirect merged/redirect Now you see foo inside a twice redirected merged dir: $ ls merged/redirect foo $ umount merged $ mount -t overlay none merged/ \ -olowerdir=middle:lower,upperdir=upper,workdir=work After mount cycle you don't see foo inside the same dir: $ ls merged/redirect During middle layer lookup, the opaqueness of middle/pure is left in the lookup state and then middle/pure/redirect is wrongly treated as opaque. Fixes: 02b69b28 ("ovl: lookup redirects") Cc: <stable@vger.kernel.org> #v4.10 Signed-off-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NVivek Goyal <vgoyal@redhat.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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由 Vivek Goyal 提交于
d->last signifies that this is the last layer we are looking into and there is no more. And that means this allows for some optimzation opportunities during lookup. For example, in ovl_lookup_single() we don't have to check for opaque xattr of a directory is this is the last layer we are looking into (d->last = true). But knowing for sure whether we are looking into last layer can be very tricky. If redirects are not enabled, then we can look at poe->numlower and figure out if the lookup we are about to is last layer or not. But if redircts are enabled then it is possible poe->numlower suggests that we are looking in last layer, but there is an absolute redirect present in found element and that redirects us to a layer in root and that means lookup will continue in lower layers further. For example, consider following. /upperdir/pure (opaque=y) /upperdir/pure/foo (opaque=y,redirect=/bar) /lowerdir/bar In this case pure is "pure upper". When we look for "foo", that time poe->numlower=0. But that alone does not mean that we will not search for a merge candidate in /lowerdir. Absolute redirect changes that. IOW, d->last should not be set just based on poe->numlower if redirects are enabled. That can lead to setting d->last while it should not have and that means we will not check for opaque xattr while we should have. So do this. - If redirects are not enabled, then continue to rely on poe->numlower information to determine if it is last layer or not. - If redirects are enabled, then set d->last = true only if this is the last layer in root ovl_entry (roe). Suggested-by: NAmir Goldstein <amir73il@gmail.com> Reviewed-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NVivek Goyal <vgoyal@redhat.com> Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com> Fixes: 02b69b28 ("ovl: lookup redirects") Cc: <stable@vger.kernel.org> #v4.10
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由 Amir Goldstein 提交于
Eddie Horng reported that readdir of an overlayfs directory that was exported via NFSv3 returns entries with d_type set to DT_UNKNOWN. The reason is that while preparing the response for readdirplus, nfsd checks inside encode_entryplus_baggage() that a child dentry's inode number matches the value of d_ino returns by overlayfs readdir iterator. Because the overlayfs inodes use arbitrary inode numbers that are not correlated with the values of st_ino/d_ino, NFSv3 falls back to not encoding d_type. Although this is an allowed behavior, we can fix it for the case of all overlayfs layers on the same underlying filesystem. When NFS export is enabled and d_ino is consistent with st_ino (samefs), set the same value also to i_ino in ovl_fill_inode() for all overlayfs inodes, nfsd readdirplus sanity checks will pass. ovl_fill_inode() may be called from ovl_new_inode(), before real inode was created with ino arg 0. In that case, i_ino will be updated to real upper inode i_ino on ovl_inode_init() or ovl_inode_update(). Reported-by: NEddie Horng <eddiehorng.tw@gmail.com> Tested-by: NEddie Horng <eddiehorng.tw@gmail.com> Signed-off-by: NAmir Goldstein <amir73il@gmail.com> Fixes: 8383f174 ("ovl: wire up NFS export operations") Cc: <stable@vger.kernel.org> #v4.16 Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
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