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2018-05-28btrfs: move clearing of EXCL_OP out of __cancel_balanceDavid Sterba
Make the clearning visible in the callers so we can pair it with the test_and_set part. Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: move volume_mutex to callers of btrfs_rm_deviceDavid Sterba
Move locking and unlocking next to the BTRFS_FS_EXCL_OP bit manipulation so it's obvious that the two happen at the same time. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: move btrfs_init_dev_replace_tgtdev to dev-replace.c and make staticDavid Sterba
The function logically belongs there and there's only a single caller, no need to export it. No code changes. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: export and rename free_deviceDavid Sterba
The function will be used outside of volumes.c, the allocation btrfs_alloc_device is also exported. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: make success path out of btrfs_init_dev_replace_tgtdev more clearDavid Sterba
This is a preparatory cleanup that will make clear that the only successful way out of btrfs_init_dev_replace_tgtdev will also set the device_out to a valid pointer. With this guarantee, the callers can be simplified. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: squeeze btrfs_dev_replace_continue_on_mount to its callerDavid Sterba
The function is called once and is fairly small, we can merge it with the caller. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: cleanup btrfs_rm_device() promote fs_devices pointerAnand Jain
This function uses fs_info::fs_devices number of time, however we declare and use it only at the end, instead do it in the beginning of the function and use it. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: cleanup find_device() drop list_head pointerAnand Jain
find_device() declares struct list_head *head pointer and used only once, instead just use it directly. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: rename __btrfs_open_devices to open_fs_devicesAnand Jain
__btrfs_open_devices() is un-exported drop __ prefix and rename it to open_fs_devices(). Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: rename __btrfs_close_devices to close_fs_devicesAnand Jain
__btrfs_close_devices() is un-exported, drop the __ prefix and rename it to close_fs_devices(). Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: cleanup __btrfs_open_devices() drop head pointerAnand Jain
__btrfs_open_devices() declares struct list_head *head, however head is used only once, instead use btrfs_fs_devices::devices directly. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: rename struct btrfs_fs_devices::listAnand Jain
btrfs_fs_devices::list is the list of BTRFS fsid in the kernel, a generic name 'list' makes it's search very difficult, rename it to fs_list. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Drop fs_info parameter from btrfs_merge_delayed_refsNikolay Borisov
It's provided by the transaction handle. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Drop fs_info parameter from add_delayed_data_refNikolay Borisov
It's provided by the transaction handle. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Drop add_delayed_ref_head fs_info parameterNikolay Borisov
It's provided by the transaction handle. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Remove btrfs_wait_and_free_delalloc_workNikolay Borisov
This function is called from only 1 place and is effectively a wrapper over wait_completion/kfree. It doesn't really bring any value having those two calls in a separate function. Just open code it and remove it. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Remove tree argument from extent_writepagesNikolay Borisov
It can be directly referenced from the passed address_space so do that. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Use list_empty instead of list_empty_carefulNikolay Borisov
list_empty_careful usually is a signal of something tricky going on. Its usage in btrfs is actually not needed since both lists it's used on are local to a function and cannot be modified concurrently. So switch to plain list_empty. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Remove redundant tree argument from extent_readpagesNikolay Borisov
This function is called only from btrfs_readpage and is already passed the mapping. Simplify its signature by moving the code obtaining reference to the extent tree in the function. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Remove map argument from try_release_extent_stateNikolay Borisov
It's not used in the function so just remove it. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Sink extent_tree arguments in try_release_extent_mappingNikolay Borisov
This function already gets the page from which the two extent trees are referenced. Simplify its signature by moving the code getting the trees inside the function. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Allow rmdir(2) to delete an empty subvolumeMisono Tomohiro
Change the behavior of rmdir(2) and allow it to delete an empty subvolume by using btrfs_delete_subvolume() which is used by btrfs_ioctl_snap_destroy(). This is a change in behaviour and has been requested by users. Deleting the subvolume by ioctl requires root permissions while the rmdir way does works with standard tools and syscalls for all users that can access the subvolume. The main usecase is to allow 'rm -rf /path/with/subvols' to simply work. We were not able to find any nasty usability surprises, the intention is to do the destructive rm. Without allowing rmdir, this would have to be followed by the ioctl subvolume deletion, which is more of an annoyance. Implementation details: The required lock for @dir and inode of @dentry is already acquired in vfs layer. We need some check before deleting a subvolume. Permission check is done in vfs layer, emptiness check is in btrfs_rmdir() and additional check (i.e. neither the subvolume is a default subvolume nor send is in progress) is in btrfs_delete_subvolume(). Note that in btrfs_ioctl_snap_destroy(), d_delete() is called after btrfs_delete_subvolume(). For rmdir(2), d_delete() is called in vfs layer later. Tested-by: Goffredo Baroncelli <kreijack@inwind.it> Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> [ enhance changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Factor out the main deletion process from btrfs_ioctl_snap_destroy()Misono Tomohiro
Factor out the second half of btrfs_ioctl_snap_destroy() as btrfs_delete_subvolume(), which performs some subvolume specific checks before deletion: 1. send is not in progress 2. the subvolume is not the default subvolume 3. the subvolume does not contain other subvolumes and actual deletion process. btrfs_delete_subvolume() requires inode_lock for both @dir and inode of @dentry. The remaining part of btrfs_ioctl_snap_destroy() is mainly permission checks. Note that call of d_delete() is not included in btrfs_delete_subvolume() as this function will also be used by btrfs_rmdir() to delete an empty subvolume and in that case d_delete() is called in VFS layer. As a result, btrfs_unlink_subvol() and may_destroy_subvol() become static functions. No functional changes. Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> [ minor comment updates ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Move may_destroy_subvol() from ioctl.c to inode.cMisono Tomohiro
This is a preparation work to refactor btrfs_ioctl_snap_destroy() and to allow rmdir(2) to delete an empty subvolume. Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> [ minor update of the function comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: remove unused le_test_bit()Howard McLauchlan
With commit b18253ec57c0 ("btrfs: optimize free space tree bitmap conversion"), there are no more callers to le_test_bit(). This patch removes le_test_bit(). Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: optimize free space tree bitmap conversionHoward McLauchlan
Presently, convert_free_space_to_extents() does a linear scan of the bitmap. We can speed this up with find_next_{bit,zero_bit}_le(). This patch replaces the linear scan with find_next_{bit,zero_bit}_le(). Testing shows a 20-33% decrease in execution time for convert_free_space_to_extents(). Since we change bitmap to be unsigned long, we have to do some casting for the bitmap cursor. In le_bitmap_set() it makes sense to use u8, as we are doing bit operations. Everywhere else, we're just using it for pointer arithmetic and not directly accessing it, so char seems more appropriate. Suggested-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: clean up le_bitmap_{set, clear}()Howard McLauchlan
le_bitmap_set() is only used by free-space-tree, so move it there and make it static. le_bitmap_clear() is not used, so remove it. Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: use fs_info for btrfs_handle_em_exist tracepointDavid Sterba
We really want to know to which filesystem the extent map events belong, but as it cannot be reached from the extent_map pointers, we need to pass it down the callchain. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: tests: pass fs_info to extent_map testsDavid Sterba
Preparatory work to pass fs_info to btrfs_add_extent_mapping so we can get a better tracepoint message. Extent maps do not need fs_info for anything so we only add a dummy one without any other initialization. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Consolidate error checking for btrfs_alloc_chunkNikolay Borisov
The second if is really a subcase of ret being less than 0. So introduce a generic if (ret < 0) check, and inside have another if which explicitly handles the -ENOSPC and any other errors. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Fix lock release orderNikolay Borisov
Locks should generally be released in the oppposite order they are acquired. Generally lock acquisiton ordering is used to ensure deadlocks don't happen. However, as becomes more complicated it's best to also maintain proper unlock order so as to avoid possible dead locks. This was found by code inspection and doesn't necessarily lead to a deadlock scenario. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Use while loop instead of labels in __endio_write_update_orderedNikolay Borisov
Currently __endio_write_update_ordered uses labels to implement what is essentially a simple while loop. This makes the code more cumbersome to follow than it actually has to be. No functional changes. No xfstest regressions were found during testing. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: add comment about BTRFS_FS_EXCL_OPAnand Jain
Adds comments about BTRFS_FS_EXCL_OP to existing comments about the device locks. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ minor updates ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Drop delayed_refs argument from btrfs_check_delayed_seqNikolay Borisov
It's used to print its pointer in a debug statement but doesn't really bring any useful information to the error message. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: rename btrfs_get_block_group_info and make it staticSu Yue
The function btrfs_get_block_group_info() was introduced by the commit 5af3e8cce8b7 ("Btrfs: make filesystem read-only when submitting barrier fails") which used it in disk-io.c. However, the function is only called in ioctl.c now. Its parameter type btrfs_ioctl_space_info* is only for ioctl. So, make it static and rename it to be original name get_block_group_info. No functional change. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Replace owner argument in add_pinned_bytes with a booleanNikolay Borisov
add_pinned_bytes really cares whether the bytes being pinned are either data or metadata. To that effect it checks whether the 'owner' argument is less than BTRFS_FIRST_FREE_OBJECTID (256). This works because owner can really have 2 types of values: a) For metadata extents it holds the level at which the parent is in the btree. This amounts to owner having the values 0-7 b) In case of modifying data extents, owner is the inode number to which those extents belongs. Let's make this more explicit byt converting the owner parameter to a boolean value and either pass it directly when we know the type of extents we are working with (i.e. in btrfs_free_tree_block). In cases when the parent function can be called on both metadata/data extents perform the check in the caller. This hopefully makes the interface of add_pinned_bytes more intuitive. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28affs: fix potential memory leak when parsing option 'prefix'Chengguang Xu
When specifying option 'prefix' multiple times, current option parsing will cause memory leak. Hence, call kfree for previous one in this case. Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-27smb3: Add ftrace tracepoints for improved SMB3 debuggingSteve French
Although dmesg logs and wireshark network traces can be helpful, being able to dynamically enable/disable tracepoints (in this case via the kernel ftrace mechanism) can also be helpful in more quickly debugging problems, and more selectively tracing the events related to the bug report. This patch adds 12 ftrace tracepoints to cifs.ko for SMB3 events in some obvious locations. Subsequent patches will add more as needed. Example use: trace-cmd record -e cifs <run test case> trace-cmd show Various trace events can be filtered. See: trace-cmd list | grep cifs for the current list of cifs tracepoints. Sample output (from mount and writing to a file): root@smf:/sys/kernel/debug/tracing/events/cifs# trace-cmd show <snip> mount.cifs-6633 [006] .... 7246.936461: smb3_cmd_done: pid=6633 tid=0x0 sid=0x0 cmd=0 mid=0 mount.cifs-6633 [006] .... 7246.936701: smb3_cmd_err: pid=6633 tid=0x0 sid=0x3d9cf8e5 cmd=1 mid=1 status=0xc0000016 rc=-5 mount.cifs-6633 [006] .... 7246.943055: smb3_cmd_done: pid=6633 tid=0x0 sid=0x3d9cf8e5 cmd=1 mid=2 mount.cifs-6633 [006] .... 7246.943298: smb3_cmd_done: pid=6633 tid=0xf9447636 sid=0x3d9cf8e5 cmd=3 mid=3 mount.cifs-6633 [006] .... 7246.943446: smb3_cmd_done: pid=6633 tid=0xf9447636 sid=0x3d9cf8e5 cmd=11 mid=4 mount.cifs-6633 [006] .... 7246.943659: smb3_cmd_done: pid=6633 tid=0xe1b781a sid=0x3d9cf8e5 cmd=3 mid=5 mount.cifs-6633 [006] .... 7246.943766: smb3_cmd_done: pid=6633 tid=0xe1b781a sid=0x3d9cf8e5 cmd=11 mid=6 mount.cifs-6633 [006] .... 7246.943937: smb3_cmd_done: pid=6633 tid=0xe1b781a sid=0x3d9cf8e5 cmd=5 mid=7 mount.cifs-6633 [006] .... 7246.944020: smb3_cmd_done: pid=6633 tid=0xe1b781a sid=0x3d9cf8e5 cmd=16 mid=8 mount.cifs-6633 [006] .... 7246.944091: smb3_cmd_done: pid=6633 tid=0xe1b781a sid=0x3d9cf8e5 cmd=16 mid=9 mount.cifs-6633 [006] .... 7246.944163: smb3_cmd_done: pid=6633 tid=0xe1b781a sid=0x3d9cf8e5 cmd=16 mid=10 mount.cifs-6633 [006] .... 7246.944218: smb3_cmd_err: pid=6633 tid=0xf9447636 sid=0x3d9cf8e5 cmd=11 mid=11 status=0xc0000225 rc=-2 mount.cifs-6633 [006] .... 7246.944219: smb3_fsctl_err: xid=0 fid=0xffffffffffffffff tid=0xf9447636 sid=0x3d9cf8e5 class=0 type=393620 rc=-2 mount.cifs-6633 [007] .... 7246.944353: smb3_cmd_done: pid=6633 tid=0xe1b781a sid=0x3d9cf8e5 cmd=16 mid=12 bash-2071 [000] .... 7256.903844: smb3_cmd_done: pid=2071 tid=0xe1b781a sid=0x3d9cf8e5 cmd=5 mid=13 bash-2071 [000] .... 7256.904172: smb3_cmd_done: pid=2071 tid=0xe1b781a sid=0x3d9cf8e5 cmd=16 mid=14 bash-2071 [000] .... 7256.904471: smb3_cmd_done: pid=2071 tid=0xe1b781a sid=0x3d9cf8e5 cmd=17 mid=15 bash-2071 [000] .... 7256.904950: smb3_cmd_done: pid=2071 tid=0xe1b781a sid=0x3d9cf8e5 cmd=5 mid=16 bash-2071 [000] .... 7256.905305: smb3_cmd_done: pid=2071 tid=0xe1b781a sid=0x3d9cf8e5 cmd=17 mid=17 bash-2071 [000] .... 7256.905688: smb3_cmd_done: pid=2071 tid=0xe1b781a sid=0x3d9cf8e5 cmd=6 mid=18 bash-2071 [000] .... 7256.905809: smb3_write_done: xid=0 fid=0xd628f511 tid=0xe1b781a sid=0x3d9cf8e5 offset=0x0 len=0x1b Signed-off-by: Steve French <stfrench@microsoft.com> Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-05-27smb3: rename encryption_required to smb3_encryption_requiredSteve French
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2018-05-27cifs: update internal module version number for cifs.ko to 2.12Steve French
Signed-off-by: Steve French <smfrench@gmail.com>
2018-05-27cifs: add a new SMB2_close_flags functionRonnie Sahlberg
And make SMB2_close just a wrapper for SMB2_close_flags. We need this as we will start to send SMB2_CLOSE pdus using special flags. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <smfrench@gmail.com>
2018-05-27cifs: store the leaseKey in the fid on SMB2_openRonnie Sahlberg
In SMB2_open(), if we got a lease we need to store this in the fid structure or else we will never be able to map a lease break back to which file/fid it applies to. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <smfrench@gmail.com>
2018-05-27cifs: fix build break when CONFIG_CIFS_DEBUG2 enabledSteve French
Previous patches "cifs: update calc_size to take a server argument" and "cifs: add server argument to the dump_detail method" were broken if CONFIG_CIFS_DEBUG2 enabled Signed-off-by: Steve French <smfrench@gmail.com> CC: Ronnie Sahlberg <lsahlber@redhat.com>
2018-05-27cifs: update calc_size to take a server argumentRonnie Sahlberg
and change the smb2 version to take heder_preamble_size into account instead of hardcoding it as 4 bytes. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2018-05-27cifs: add server argument to the dump_detail methodRonnie Sahlberg
We need a struct TCP_Server_Info *server to this method as it calls calc_size. The calc_size method will soon be changed to also take a server argument. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2018-05-27smb3: fix redundant opens on rootSteve French
In SMB2/SMB3 unlike in cifs we unnecessarily open the root of the share over and over again in various places during mount and path revalidation and also in statfs. This patch cuts redundant traffic (opens and closes) by simply keeping the directory handle for the root around (and reopening it as needed on reconnect), so query calls don't require three round trips to copmlete - just one, and eases load on network, client and server (on mount alone, cuts network traffic by more than a third). Also add a new cifs mount parm "nohandlecache" to allow users whose servers might have resource constraints (eg in case they have a server with so many users connecting to it that this extra handle per mount could possibly be a resource concern). Signed-off-by: Steve French <smfrench@gmail.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-05-27rmdir(),rename(): do shrink_dcache_parent() only on successAl Viro
Once upon a time ->rmdir() instances used to check if victim inode had more than one (in-core) reference and failed with -EBUSY if it had. The reason was race avoidance - emptiness check is worthless if somebody could just go and create new objects in the victim directory afterwards. With introduction of dcache the checks had been replaced with checking the refcount of dentry. However, since a cached negative lookup leaves a negative child dentry, such check had lead to false positives - with empty foo/ doing stat foo/bar before rmdir foo ended up with -EBUSY unless the negative dentry of foo/bar happened to be evicted by the time of rmdir(2). That had been fixed by doing shrink_dcache_parent() just before the refcount check. At the same time, ext2_rmdir() has grown a private solution that eliminated those -EBUSY - it did something (setting ->i_size to 0) which made any subsequent ext2_add_entry() fail. Unfortunately, even with shrink_dcache_parent() the check had been racy - after all, the victim itself could be found by dcache lookup just after we'd checked its refcount. That got fixed by a new helper (dentry_unhash()) that did shrink_dcache_parent() and unhashed the sucker if its refcount ended up equal to 1. That got called before ->rmdir(), turning the checks in ->rmdir() instances into "if not unhashed fail with -EBUSY". Which reduced the boilerplate nicely, but had an unpleasant side effect - now shrink_dcache_parent() had been done before the emptiness checks, leading to easily triggerable calls of shrink_dcache_parent() on arbitrary large subtrees, quite possibly nested into each other. Several years later the ext2-private trick had been generalized - (in-core) inodes of dead directories are flagged and calls of lookup, readdir and all directory-modifying methods were prevented in so marked directories. Remaining boilerplate in ->rmdir() instances became redundant and some instances got rid of it. In 2011 the call of dentry_unhash() got shifted into ->rmdir() instances and then killed off in all of them. That has lead to another problem, though - in case of successful rmdir we *want* any (negative) child dentries dropped and the victim itself made negative. There's no point keeping cached negative lookups in foo when we can get the negative lookup of foo itself cached. So shrink_dcache_parent() call had been restored; unfortunately, it went into the place where dentry_unhash() used to be, i.e. before the ->rmdir() call. Note that we don't unhash anymore, so any "is it busy" checks would be racy; fortunately, all of them are gone. We should've done that call right *after* successful ->rmdir(). That reduces contention caused by tree-walking in shrink_dcache_parent() and, especially, contention caused by evictions in two nested subtrees going on in parallel. The same goes for directory-overwriting rename() - the story there had been parallel to that of rmdir(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Lots of easy overlapping changes in the confict resolutions here. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-26switch the rest of procfs lookups to d_splice_alias()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-26procfs: switch instantiate_t to d_splice_alias()Al Viro
... and get rid of pointless struct inode *dir argument of those, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>