- 22 1月, 2014 12 次提交
-
-
由 Younger Liu 提交于
ocfs2_alloc_dinode_update_counts() and ocfs2_block_group_set_bits() are already provided in suballoc.c. So, the same functions in move_extents.c are not needed any more. Declare the functions in suballoc.h and remove redundant functions in move_extents.c. Signed-off-by: NYounger Liu <liuyiyang@hisense.com> Cc: Younger Liu <younger.liucn@gmail.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Goldwyn Rodrigues 提交于
Attempt to use the new DLM operations. If it is not supported, use the traditional ocfs2_controld. To exchange ocfs2 versioning, we use the LVB of the version dlm lock. It first attempts to take the lock in EX mode (non-blocking). If successful (which means it is the first mount), it writes the version number and downconverts to PR lock. If it is unsuccessful, it reads the version from the lock. If this becomes the standard (with o2cb as well), it could simplify userspace tools to check if the filesystem is mounted on other nodes. Dan: Since ocfs2_protocol_version are two u8 values, the additional checks with LONG* don't make sense. Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com> Reviewed-by: NMark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Goldwyn Rodrigues 提交于
Use the native DLM locks for version control negotiation. Most of the framework is taken from gfs2/lock_dlm.c Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: NMark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Goldwyn Rodrigues 提交于
This is done to differentiate between using and not using controld and use the connection information accordingly. We need to be backward compatible. So, we use a new enum ocfs2_connection_type to identify when controld is used and when it is not. Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: NMark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Goldwyn Rodrigues 提交于
We perform this because the DLM recovery callbacks will require the ocfs2_live_connection structure to record the node information when dlm_new_lockspace() is updated (in the last patch of the series). Before calling dlm_new_lockspace(), we need the structure ready for the .recover_done() callback, which would set oc_this_node. This is the reason we allocate ocfs2_live_connection beforehand in user_connect(). [AKPM] rc initialization is not required because it assigned in case of errors. It will be cleared by compiler anyways. Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com> Reveiwed-by: NMark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Goldwyn Rodrigues 提交于
These are the callbacks called by the fs/dlm code in case the membership changes. If there is a failure while/during calling any of these, the DLM creates a new membership and relays to the rest of the nodes. - recover_prep() is called when DLM understands a node is down. - recover_slot() is called once all nodes have acknowledged recover_prep and recovery can begin. - recover_done() is called once the recovery is complete. It returns the new membership. Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: NMark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Goldwyn Rodrigues 提交于
This is an effort of removing ocfs2_controld.pcmk and getting ocfs2 DLM handling up to the times with respect to DLM (>=4.0.1) and corosync (2.3.x). AFAIK, cman also is being phased out for a unified corosync cluster stack. fs/dlm performs all the functions with respect to fencing and node management and provides the API's to do so for ocfs2. For all future references, DLM stands for fs/dlm code. The advantages are: + No need to run an additional userspace daemon (ocfs2_controld) + No controld device handling and controld protocol + Shifting responsibilities of node management to DLM layer For backward compatibility, we are keeping the controld handling code. Once enough time has passed we can remove a significant portion of the code. This was tested by using the kernel with changes on older unmodified tools. The kernel used ocfs2_controld as expected, and displayed the appropriate warning message. This feature requires modification in the userspace ocfs2-tools. The changes can be found at: https://github.com/goldwynr/ocfs2-tools branch: nocontrold Currently, not many checks are present in the userspace code, but that would change soon. This patch (of 6): Add clustername to cluster connection. Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: NMark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Goldwyn Rodrigues 提交于
The versioning information is confusing for end-users. The numbers are stuck at 1.5.0 when the tools version have moved to 1.8.2. Remove the versioning system in the OCFS2 modules and let the kernel version be the guide to debug issues. Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com> Acked-by: NSunil Mushran <sunil.mushran@gmail.com> Cc: Mark Fasheh <mfasheh@suse.com> Acked-by: NJoel Becker <jlbec@evilplan.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Jan Kara 提交于
We usually rely on the fact that struct members not specified in the initializer are set to NULL. So do that with fsnotify function pointers as well. Signed-off-by: NJan Kara <jack@suse.cz> Reviewed-by: NChristoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> 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>
-
由 Jan Kara 提交于
After removing event structure creation from the generic layer there is no reason for separate .should_send_event and .handle_event callbacks. So just remove the first one. Signed-off-by: NJan Kara <jack@suse.cz> Reviewed-by: NChristoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> 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>
-
由 Jan Kara 提交于
Currently fsnotify framework creates one event structure for each notification event and links this event into all interested notification groups. This is done so that we save memory when several notification groups are interested in the event. However the need for event structure shared between inotify & fanotify bloats the event structure so the result is often higher memory consumption. Another problem is that fsnotify framework keeps path references with outstanding events so that fanotify can return open file descriptors with its events. This has the undesirable effect that filesystem cannot be unmounted while there are outstanding events - a regression for inotify compared to a situation before it was converted to fsnotify framework. For fanotify this problem is hard to avoid and users of fanotify should kind of expect this behavior when they ask for file descriptors from notified files. This patch changes fsnotify and its users to create separate event structure for each group. This allows for much simpler code (~400 lines removed by this patch) and also smaller event structures. For example on 64-bit system original struct fsnotify_event consumes 120 bytes, plus additional space for file name, additional 24 bytes for second and each subsequent group linking the event, and additional 32 bytes for each inotify group for private data. After the conversion inotify event consumes 48 bytes plus space for file name which is considerably less memory unless file names are long and there are several groups interested in the events (both of which are uncommon). Fanotify event fits in 56 bytes after the conversion (fanotify doesn't care about file names so its events don't have to have it allocated). A win unless there are four or more fanotify groups interested in the event. The conversion also solves the problem with unmount when only inotify is used as we don't have to grab path references for inotify events. [hughd@google.com: fanotify: fix corruption preventing startup] Signed-off-by: NJan Kara <jack@suse.cz> Reviewed-by: NChristoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NHugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Jan Kara 提交于
Rounding of name length when passing it to userspace was done in several places. Provide a function to do it and use it in all places. Signed-off-by: NJan Kara <jack@suse.cz> Reviewed-by: NChristoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> 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>
-
- 18 1月, 2014 1 次提交
-
-
由 Tejun Heo 提交于
Once created, a kernfs_node is always destroyed by kernfs_put(). Since ba7443bc ("sysfs, kernfs: implement kernfs_create/destroy_root()"), kernfs_put() depends on kernfs_root() to locate the ino_ida. kernfs_root() in turn depends on kernfs_node->parent being set for !dir nodes. This means that kernfs_put() of a !dir node requires its ->parent to be initialized. This leads to oops when a newly created !dir node is destroyed without going through kernfs_add_one() or after failing kernfs_add_one() before ->parent is set. kernfs_root() invoked from kernfs_put() will try to dereference NULL parent. Fix it by moving parent association to kernfs_new_node() from kernfs_add_one(). kernfs_new_node() now takes @parent instead of @root and determines the root from the parent and also sets the new node's parent properly. @parent parameter is removed from kernfs_add_one(). As there's no parent when creating the root node, __kernfs_new_node() which takes @root as before and doesn't set the parent is used in that case. This ensures that a kernfs_node in any stage in its life has its parent associated and thus can be put. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
- 15 1月, 2014 2 次提交
-
-
由 Andreas Rohner 提交于
There is a bug in the function nilfs_segctor_collect, which results in active data being written to a segment, that is marked as clean. It is possible, that this segment is selected for a later segment construction, whereby the old data is overwritten. The problem shows itself with the following kernel log message: nilfs_sufile_do_cancel_free: segment 6533 must be clean Usually a few hours later the file system gets corrupted: NILFS: bad btree node (blocknr=8748107): level = 0, flags = 0x0, nchildren = 0 NILFS error (device sdc1): nilfs_bmap_last_key: broken bmap (inode number=114660) The issue can be reproduced with a file system that is nearly full and with the cleaner running, while some IO intensive task is running. Although it is quite hard to reproduce. This is what happens: 1. The cleaner starts the segment construction 2. nilfs_segctor_collect is called 3. sc_stage is on NILFS_ST_SUFILE and segments are freed 4. sc_stage is on NILFS_ST_DAT current segment is full 5. nilfs_segctor_extend_segments is called, which allocates a new segment 6. The new segment is one of the segments freed in step 3 7. nilfs_sufile_cancel_freev is called and produces an error message 8. Loop around and the collection starts again 9. sc_stage is on NILFS_ST_SUFILE and segments are freed including the newly allocated segment, which will contain active data and can be allocated at a later time 10. A few hours later another segment construction allocates the segment and causes file system corruption This can be prevented by simply reordering the statements. If nilfs_sufile_cancel_freev is called before nilfs_segctor_extend_segments the freed segments are marked as dirty and cannot be allocated any more. Signed-off-by: NAndreas Rohner <andreas.rohner@gmx.net> Reviewed-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Tested-by: NAndreas Rohner <andreas.rohner@gmx.net> Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Tejun Heo 提交于
When kernfs_seq_start() fails to obtain an active reference, it returns ERR_PTR(-ENODEV). kernfs_seq_stop() is then invoked with the error pointer value; however, it still proceeds to invoke kernfs_put_active() on the node leading to unbalanced put. If kernfs_seq_stop() is called even after active ref failure, it should skip invocation of @ops->seq_stop() and put_active. Unfortunately, this is a bit complicated because active ref failure isn't the only thing which may fail with ERR_PTR(-ENODEV). @ops->seq_start/next() may also fail with the error value and kernfs_seq_stop() doesn't have a way to tell apart those failures. Work it around by factoring out the active part of kernfs_seq_stop() into kernfs_seq_stop_active() and invoking it directly if @ops->seq_start/next() fail with ERR_PTR(-ENODEV) and updating kernfs_seq_stop() to skip kernfs_seq_stop_active() on ERR_PTR(-ENODEV). This is a bit nasty but ensures that the active put is skipped iff get_active failed in kernfs_seq_start(). tj: This was originally committed as d92d2e6b but got reverted by 683bb276 along with other kernfs self removal patches. However, this one is an independent fix and shouldn't have been reverted together. Reinstate the change. Sorry about the mess. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
- 14 1月, 2014 12 次提交
-
-
由 Greg Kroah-Hartman 提交于
This reverts commit d92d2e6b. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Greg Kroah-Hartman 提交于
This reverts commit ea1c472d. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Greg Kroah-Hartman 提交于
This reverts commit a69d001c. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Greg Kroah-Hartman 提交于
This reverts commit ae34372e. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Greg Kroah-Hartman 提交于
This reverts commit 45a140e5. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Greg Kroah-Hartman 提交于
This reverts commit f601f9a2. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Greg Kroah-Hartman 提交于
This reverts commit 99177a34. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Greg Kroah-Hartman 提交于
This reverts commit 895a068a. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Greg Kroah-Hartman 提交于
This reverts commit 9f010c2a. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Greg Kroah-Hartman 提交于
This reverts commit 1ae06819. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Greg Kroah-Hartman 提交于
This reverts commit d1ba277e. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Greg Kroah-Hartman 提交于
This reverts commit 88533f99. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
- 12 1月, 2014 1 次提交
-
-
由 Tejun Heo 提交于
895a068a ("kernfs: make kernfs_get_active() block if the node is deactivated but not removed") added "struct kernfs_root *root = kernfs_root(kn);" at the head of the function; however, the parameter @kn is checked for later implying that the function may be called with NULL. This means that we may end up invoking kernfs_root() with NULL which will oops. None of the existing users invokes removal with NULL @kn, so this bug doesn't actually trigger. We can relocate kernfs_root() invocation after NULL check; however, allowing NULL param tends to cause more confusion than actually helping anything. As there's no existing user, let's remove the spurious NULL check. This bug was detected by smatch. Signed-off-by: NTejun Heo <tj@kernel.org> Reported-by: NDan Carpenter <dan.carpenter@oracle.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
- 11 1月, 2014 12 次提交
-
-
由 Tejun Heo 提交于
All device_schedule_callback_owner() users are converted to use device_remove_file_self(). Remove now unused {sysfs|device}_schedule_callback_owner(). Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Tejun Heo 提交于
Sometimes it's necessary to implement a node which wants to delete nodes including itself. This isn't straightforward because of kernfs active reference. While a file operation is in progress, an active reference is held and kernfs_remove() waits for all such references to drain before completing. For a self-deleting node, this is a deadlock as kernfs_remove() ends up waiting for an active reference that itself is sitting on top of. This currently is worked around in the sysfs layer using sysfs_schedule_callback() which makes such removals asynchronous. While it works, it's rather cumbersome and inherently breaks synchronicity of the operation - the file operation which triggered the operation may complete before the removal is finished (or even started) and the removal may fail asynchronously. If a removal operation is immmediately followed by another operation which expects the specific name to be available (e.g. removal followed by rename onto the same name), there's no way to make the latter operation reliable. The thing is there's no inherent reason for this to be asynchrnous. All that's necessary to do this synchronous is a dedicated operation which drops its own active ref and deactivates self. This patch implements kernfs_remove_self() and its wrappers in sysfs and driver core. kernfs_remove_self() is to be called from one of the file operations, drops the active ref and deactivates using __kernfs_deactivate_self(), removes the self node, and restores active ref to the dead node using __kernfs_reactivate_self() so that the ref is balanced afterwards. __kernfs_remove() is updated so that it takes an early exit if the target node is already fully removed so that the active ref restored by kernfs_remove_self() after removal doesn't confuse the deactivation path. This makes implementing self-deleting nodes very easy. The normal removal path doesn't even need to be changed to use kernfs_remove_self() for the self-deleting node. The method can invoke kernfs_remove_self() on itself before proceeding the normal removal path. kernfs_remove() invoked on the node by the normal deletion path will simply be ignored. This will replace sysfs_schedule_callback(). A subtle feature of sysfs_schedule_callback() is that it collapses multiple invocations - even if multiple removals are triggered, the removal callback is run only once. An equivalent effect can be achieved by testing the return value of kernfs_remove_self() - only the one which gets %true return value should proceed with actual deletion. All other instances of kernfs_remove_self() will wait till the enclosing kernfs operation which invoked the winning instance of kernfs_remove_self() finishes and then return %false. This trivially makes all users of kernfs_remove_self() automatically show correct synchronous behavior even when there are multiple concurrent operations - all "echo 1 > delete" instances will finish only after the whole operation is completed by one of the instances. v2: For !CONFIG_SYSFS, dummy version kernfs_remove_self() was missing and sysfs_remove_file_self() had incorrect return type. Fix it. Reported by kbuild test bot. v3: Updated to use __kernfs_{de|re}activate_self(). Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Tejun Heo 提交于
This patch implements four functions to manipulate deactivation state - deactivate, reactivate and the _self suffixed pair. A new fields kernfs_node->deact_depth is added so that concurrent and nested deactivations are handled properly. kernfs_node->hash is moved so that it's paired with the new field so that it doesn't increase the size of kernfs_node. A kernfs user's lock would normally nest inside active ref but during removal the user may want to perform kernfs_remove() while holding the said lock, which would introduce a reverse locking dependency. This function can be used to break such reverse dependency by allowing deactivation step to performed separately outside user's critical section. This will also be used implement kernfs_remove_self(). Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Tejun Heo 提交于
Currently, kernfs_get_active() fails if the target node is deactivated. This is fine as a node always gets removed after deactivation; however, we're gonna add reactivation so the assumption won't hold. It'd be incorrect for kernfs_get_active() to fail for a node which was deactivated only temporarily. This patch makes kernfs_get_active() block if the node is deactivated but not removed. If the node gets reactivated (not yet implemented), it will be retried and succeed. If the node gets removed, it will be woken up and fail. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Tejun Heo 提交于
kernfs_addrm_cxt and the accompanying kernfs_addrm_start/finish() were added because there were operations which should be performed outside kernfs_mutex after adding and removing kernfs_nodes. The necessary operations were recorded in kernfs_addrm_cxt and performed by kernfs_addrm_finish(); however, after the recent changes which relocated deactivation and unmapping so that they're performed directly during removal, the only operation kernfs_addrm_finish() performs is kernfs_put(), which can be moved inside the removal path too. This patch moves the kernfs_put() of the base ref to __kernfs_remove() and remove kernfs_addrm_cxt and kernfs_addrm_start/finish(). * kernfs_add_one() is updated to grab and release the parent's active ref and kernfs_mutex itself. kernfs_get/put_active() and kernfs_addrm_start/finish() invocations around it are removed from all users. * __kernfs_remove() puts an unlinked node directly instead of chaining it to kernfs_addrm_cxt. Its callers are updated to grab and release kernfs_mutex instead of calling kernfs_addrm_start/finish() around it. v2: Updated to fit the v2 restructuring of removal path. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Tejun Heo 提交于
kernfs_unmap_bin_file() is supposed to unmap all memory mappings of the target file before kernfs_remove() finishes; however, it currently is being called from kernfs_addrm_finish() and has the same race problem as the original implementation of deactivation when there are multiple removers - only the remover which snatches the node to its addrm_cxt->removed list is guaranteed to wait for its completion before returning. It can be fixed by moving kernfs_unmap_bin_file() invocation from kernfs_addrm_finish() to __kernfs_remove(). The function may be called multiple times but that shouldn't do any harm. We end up dropping kernfs_mutex in the removal loop and the node may be removed inbetween by someone else. kernfs_unlink_sibling() is updated to test whether the node has already been removed and return accordingly. __kernfs_remove() in turn performs post-unlinking cleanup only if it actually unlinked the node. KERNFS_HAS_MMAP test is moved out of the unmap function into __kernfs_remove() so that we don't unlock kernfs_mutex unnecessarily. While at it, drop the now meaningless "bin" qualifier from the function name. v2: Rewritten to fit the v2 restructuring of removal path. HAS_MMAP test relocated. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Tejun Heo 提交于
The recursive nature of kernfs_remove() means that, even if kernfs_remove() is not allowed to be called multiple times on the same node, there may be race conditions between removal of parent and its descendants. While we can claim that kernfs_remove() shouldn't be called on one of the descendants while the removal of an ancestor is in progress, such rule is unnecessarily restrictive and very difficult to enforce. It's better to simply allow invoking kernfs_remove() as the caller sees fit as long as the caller ensures that the node is accessible. The current behavior in such situations is broken. Whoever enters removal path first takes the node off the hierarchy and then deactivates. Following removers either return as soon as it notices that it's not the first one or can't even find the target node as it has already been removed from the hierarchy. In both cases, the following removers may finish prematurely while the nodes which should be removed and drained are still being processed by the first one. This patch restructures so that multiple removers, whether through recursion or direction invocation, always follow the following rules. * When there are multiple concurrent removers, only one puts the base ref. * Regardless of which one puts the base ref, all removers are blocked until the target node is fully deactivated and removed. To achieve the above, removal path now first deactivates the subtree, drains it and then unlinks one-by-one. __kernfs_deactivate() is called directly from __kernfs_removal() and drops and regrabs kernfs_mutex for each descendant to drain active refs. As this means that multiple removers can enter __kernfs_deactivate() for the same node, the function is updated so that it can handle multiple deactivators of the same node - only one actually deactivates but all wait till drain completion. The restructured removal path guarantees that a removed node gets unlinked only after the node is deactivated and drained. Combined with proper multiple deactivator handling, this guarantees that any invocation of kernfs_remove() returns only after the node itself and all its descendants are deactivated, drained and removed. v2: Draining separated into a separate loop (used to be in the same loop as unlink) and done from __kernfs_deactivate(). This is to allow exposing deactivation as a separate interface later. Root node removal was broken in v1 patch. Fixed. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Tejun Heo 提交于
KERNFS_REMOVED is used to mark half-initialized and dying nodes so that they don't show up in lookups and deny adding new nodes under or renaming it; however, its role overlaps those of deactivation and removal from rbtree. It's necessary to deny addition of new children while removal is in progress; however, this role considerably intersects with deactivation - KERNFS_REMOVED prevents new children while deactivation prevents new file operations. There's no reason to have them separate making things more complex than necessary. KERNFS_REMOVED is also used to decide whether a node is still visible to vfs layer, which is rather redundant as equivalent determination can be made by testing whether the node is on its parent's children rbtree or not. This patch removes KERNFS_REMOVED. * Instead of KERNFS_REMOVED, each node now starts its life deactivated. This means that we now use both atomic_add() and atomic_sub() on KN_DEACTIVATED_BIAS, which is INT_MIN. The compiler generates an overflow warnings when negating INT_MIN as the negation can't be represented as a positive number. Nothing is actually broken but let's bump BIAS by one to avoid the warnings for archs which negates the subtrahend.. * KERNFS_REMOVED tests in add and rename paths are replaced with kernfs_get/put_active() of the target nodes. Due to the way the add path is structured now, active ref handling is done in the callers of kernfs_add_one(). This will be consolidated up later. * kernfs_remove_one() is updated to deactivate instead of setting KERNFS_REMOVED. This removes deactivation from kernfs_deactivate(), which is now renamed to kernfs_drain(). * kernfs_dop_revalidate() now tests RB_EMPTY_NODE(&kn->rb) instead of KERNFS_REMOVED and KERNFS_REMOVED test in kernfs_dir_pos() is dropped. A node which is removed from the children rbtree is not included in the iteration in the first place. This means that a node may be visible through vfs a bit longer - it's now also visible after deactivation until the actual removal. This slightly enlarged window difference doesn't make any difference to the userland. * Sanity check on KERNFS_REMOVED in kernfs_put() is replaced with checks on the active ref. * Some comment style updates in the affected area. v2: Reordered before removal path restructuring. kernfs_active() dropped and kernfs_get/put_active() used instead. RB_EMPTY_NODE() used in the lookup paths. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Tejun Heo 提交于
There currently are two mechanisms gating active ref lockdep annotations - KERNFS_LOCKDEP flag and KERNFS_ACTIVE_REF type mask. The former disables lockdep annotations in kernfs_get/put_active() while the latter disables all of kernfs_deactivate(). While KERNFS_ACTIVE_REF also behaves as an optimization to skip the deactivation step for non-file nodes, the benefit is marginal and it needlessly diverges code paths. Let's drop KERNFS_ACTIVE_REF and use KERNFS_LOCKDEP in kernfs_deactivate() too. While at it, add a test helper kernfs_lockdep() to test KERNFS_LOCKDEP flag so that it's more convenient and the related code can be compiled out when not enabled. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Tejun Heo 提交于
kernfs_node->u.completion is used to notify deactivation completion from kernfs_put_active() to kernfs_deactivate(). We now allow multiple racing removals of the same node and the current removal scheme is no longer correct - kernfs_remove() invocation may return before the node is properly deactivated if it races against another removal. The removal path will be restructured to address the issue. To help such restructure which requires supporting multiple waiters, this patch replaces kernfs_node->u.completion with kernfs_root->deactivate_waitq. This makes deactivation event notifications share a per-root waitqueue_head; however, the wait path is quite cold and this will also allow shaving one pointer off kernfs_node. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Tejun Heo 提交于
When kernfs_seq_start() fails to obtain an active reference, it returns ERR_PTR(-ENODEV). kernfs_seq_stop() is then invoked with the error pointer value; however, it still proceeds to invoke kernfs_put_active() on the node leading to unbalanced put. If kernfs_seq_stop() is called even after active ref failure, it should skip invocation of @ops->seq_stop() and put_active. Unfortunately, this is a bit complicated because active ref failure isn't the only thing which may fail with ERR_PTR(-ENODEV). @ops->seq_start/next() may also fail with the error value and kernfs_seq_stop() doesn't have a way to tell apart those failures. Work it around by factoring out the active part of kernfs_seq_stop() into kernfs_seq_stop_active() and invoking it directly if @ops->seq_start/next() fail with ERR_PTR(-ENODEV) and updating kernfs_seq_stop() to skip kernfs_seq_stop_active() on ERR_PTR(-ENODEV). This is a bit nasty but ensures that the active put is skipped iff get_active failed in kernfs_seq_start(). Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
-
由 Chuansheng Liu 提交于
In case CONFIG_DEBUG_OBJECTS_WORK is defined, it is needed to call destroy_work_on_stack() which frees the debug object to pair with INIT_WORK_ONSTACK(). Signed-off-by: NLiu, Chuansheng <chuansheng.liu@intel.com> Reviewed-by: NBen Myers <bpm@sgi.com> Signed-off-by: NBen Myers <bpm@sgi.com> (cherry picked from commit 6f96b306)
-