- 10 May, 2013 2 commits
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Masami Hiramatsu authored
Cleanup regex_lock and ftrace_lock locking points around ftrace_ops hash update code. The new rule is that regex_lock protects ops->*_hash read-update-write code for each ftrace_ops. Usually, hash update is done by following sequence. 1. allocate a new local hash and copy the original hash. 2. update the local hash. 3. move(actually, copy) back the local hash to ftrace_ops. 4. update ftrace entries if needed. 5. release the local hash. This makes regex_lock protect #1-#4, and ftrace_lock to protect #3, #4 and adding and removing ftrace_ops from the ftrace_ops_list. The ftrace_lock protects #3 as well because the move functions update the entries too. Link: http://lkml.kernel.org/r/20130509054421.30398.83411.stgit@mhiramat-M0-7522 Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Signed-off-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by:
Steven Rostedt <rostedt@goodmis.org>
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Masami Hiramatsu authored
Fix a deadlock on ftrace_regex_lock which happens when setting an enable_event trigger on dynamic kprobe event as below. ---- sh-2.05b# echo p vfs_symlink > kprobe_events sh-2.05b# echo vfs_symlink:enable_event:kprobes:p_vfs_symlink_0 > set_ftrace_filter ============================================= [ INFO: possible recursive locking detected ] 3.9.0+ #35 Not tainted --------------------------------------------- sh/72 is trying to acquire lock: (ftrace_regex_lock){+.+.+.}, at: [<ffffffff810ba6c1>] ftrace_set_hash+0x81/0x1f0 but task is already holding lock: (ftrace_regex_lock){+.+.+.}, at: [<ffffffff810b7cbd>] ftrace_regex_write.isra.29.part.30+0x3d/0x220 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(ftrace_regex_lock); lock(ftrace_regex_lock); *** DEADLOCK *** ---- To fix that, this introduces a finer regex_lock for each ftrace_ops. ftrace_regex_lock is too big of a lock which protects all filter/notrace_hash operations, but it doesn't need to be a global lock after supporting multiple ftrace_ops because each ftrace_ops has its own filter/notrace_hash. Link: http://lkml.kernel.org/r/20130509054417.30398.84254.stgit@mhiramat-M0-7522 Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Signed-off-by:
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- 09 May, 2013 3 commits
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Steven Rostedt (Red Hat) authored
As ftrace_regex_write() reads the result of ftrace_process_regex() which can sometimes return a positive number, only consider a failure if the return is negative. Otherwise, it will skip possible other registered probes and by returning a positive number that wasn't read, it will confuse the user processes doing the writing. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: -
Steven Rostedt (Red Hat) authored
register_ftrace_function_probe() returns the number of functions it registered, which can be zero, it can also return a negative number if something went wrong. But event_enable_func() only checks for the case that it didn't register anything, it needs to also check for the case that something went wrong and return that error code as well. Added some comments about the code as well, to make it more understandable. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: -
Masami Hiramatsu authored
Return 0 instead of the number of activated ftrace function probes if event_enable_func succeeded and return an error code if it failed or did not register any functions. But it currently returns the number of registered functions and if it didn't register anything, it returns 0, but that is considered success. This also fixes the return value. As if it succeeds, it returns the number of functions that were enabled, which is returned back to the user in ftrace_regex_write (the write() return code). If only one function is enabled, then the return code of the write is one, and this can confuse the user program in thinking it only wrote 1 byte. Link: http://lkml.kernel.org/r/20130509054413.30398.55650.stgit@mhiramat-M0-7522 Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Signed-off-by:
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- 03 May, 2013 1 commit
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Steven Rostedt (Red Hat) authored
As the wake up logic for waiters on the buffer has been moved from the tracing code to the ring buffer, it requires also adding IRQ_WORK as the wake up code is performed via irq_work. This fixes compile breakage when a user of the ring buffer is selected but tracing and irq_work are not. Link http://lkml.kernel.org/r/20130503115332.GT8356@rric.localhost Cc: Arnd Bergmann <arnd@arndb.de> Reported-by:
Robert Richter <rric@kernel.org> Signed-off-by:
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- 30 Apr, 2013 34 commits
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Steven Rostedt authored
During the 3.10 merge, a conflict happened and the resolution was almost, but not quite, correct. An if statement was reversed. Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds authored
Merge tag 'localmodconfig-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-kconfig Pull localmodconfig changes from Steven Rostedt: "A bug was recently found in the make localmodconfig where it would miss dependencies of config files are include in other config files inside an if statement. Also added a debug print that helped in solving this bug." * tag 'localmodconfig-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-kconfig: localmodconfig: Process source kconfig files as they are found localmodconfig: Add debug prints for dependencies of module configs
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Linus Torvalds authored
Merge second batch of fixes from Andrew Morton: - various misc bits - some printk updates - a new "SRAM" driver. - MAINTAINERS updates - the backlight driver queue - checkpatch updates - a few init/ changes - a huge number of drivers/rtc changes - fatfs updates - some lib/idr.c work - some renaming of the random driver interfaces * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (285 commits) net: rename random32 to prandom net/core: remove duplicate statements by do-while loop net/core: rename random32() to prandom_u32() net/netfilter: rename random32() to prandom_u32() net/sched: rename random32() to prandom_u32() net/sunrpc: rename random32() to prandom_u32() scsi: rename random32() to prandom_u32() lguest: rename random32() to prandom_u32() uwb: rename random32() to prandom_u32() video/uvesafb: rename random32() to prandom_u32() mmc: rename random32() to prandom_u32() drbd: rename random32() to prandom_u32() kernel/: rename random32() to prandom_u32() mm/: rename random32() to prandom_u32() lib/: rename random32() to prandom_u32() x86: rename random32() to prandom_u32() x86: pageattr-test: remove srandom32 call uuid: use prandom_bytes() raid6test: use prandom_bytes() sctp: convert sctp_assoc_set_id() to use idr_alloc_cyclic() ...
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroupLinus Torvalds authored
Pull cgroup updates from Tejun Heo: - Fixes and a lot of cleanups. Locking cleanup is finally complete. cgroup_mutex is no longer exposed to individual controlelrs which used to cause nasty deadlock issues. Li fixed and cleaned up quite a bit including long standing ones like racy cgroup_path(). - device cgroup now supports proper hierarchy thanks to Aristeu. - perf_event cgroup now supports proper hierarchy. - A new mount option "__DEVEL__sane_behavior" is added. As indicated by the name, this option is to be used for development only at this point and generates a warning message when used. Unfortunately, cgroup interface currently has too many brekages and inconsistencies to implement a consistent and unified hierarchy on top. The new flag is used to collect the behavior changes which are necessary to implement consistent unified hierarchy. It's likely that this flag won't be used verbatim when it becomes ready but will be enabled implicitly along with unified hierarchy. The option currently disables some of broken behaviors in cgroup core and also .use_hierarchy switch in memcg (will be routed through -mm), which can be used to make very unusual hierarchy where nesting is partially honored. It will also be used to implement hierarchy support for blk-throttle which would be impossible otherwise without introducing a full separate set of control knobs. This is essentially versioning of interface which isn't very nice but at this point I can't see any other options which would allow keeping the interface the same while moving towards hierarchy behavior which is at least somewhat sane. The planned unified hierarchy is likely to require some level of adaptation from userland anyway, so I think it'd be best to take the chance and update the interface such that it's supportable in the long term. Maintaining the existing interface does complicate cgroup core but shouldn't put too much strain on individual controllers and I think it'd be manageable for the foreseeable future. Maybe we'll be able to drop it in a decade. Fix up conflicts (including a semantic one adding a new #include to ppc that was uncovered by header the file changes) as per Tejun. * 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (45 commits) cpuset: fix compile warning when CONFIG_SMP=n cpuset: fix cpu hotplug vs rebuild_sched_domains() race cpuset: use rebuild_sched_domains() in cpuset_hotplug_workfn() cgroup: restore the call to eventfd->poll() cgroup: fix use-after-free when umounting cgroupfs cgroup: fix broken file xattrs devcg: remove parent_cgroup. memcg: force use_hierarchy if sane_behavior cgroup: remove cgrp->top_cgroup cgroup: introduce sane_behavior mount option move cgroupfs_root to include/linux/cgroup.h cgroup: convert cgroupfs_root flag bits to masks and add CGRP_ prefix cgroup: make cgroup_path() not print double slashes Revert "cgroup: remove bind() method from cgroup_subsys." perf: make perf_event cgroup hierarchical cgroup: implement cgroup_is_descendant() cgroup: make sure parent won't be destroyed before its children cgroup: remove bind() method from cgroup_subsys. devcg: remove broken_hierarchy tag cgroup: remove cgroup_lock_is_held() ...
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds authored
Pull workqueue updates from Tejun Heo: "A lot of activities on workqueue side this time. The changes achieve the followings. - WQ_UNBOUND workqueues - the workqueues which are per-cpu - are updated to be able to interface with multiple backend worker pools. This involved a lot of churning but the end result seems actually neater as unbound workqueues are now a lot closer to per-cpu ones. - The ability to interface with multiple backend worker pools are used to implement unbound workqueues with custom attributes. Currently the supported attributes are the nice level and CPU affinity. It may be expanded to include cgroup association in future. The attributes can be specified either by calling apply_workqueue_attrs() or through /sys/bus/workqueue/WQ_NAME/* if the workqueue in question is exported through sysfs. The backend worker pools are keyed by the actual attributes and shared by any workqueues which share the same attributes. When attributes of a workqueue are changed, the workqueue binds to the worker pool with the specified attributes while leaving the work items which are already executing in its previous worker pools alone. This allows converting custom worker pool implementations which want worker attribute tuning to use workqueues. The writeback pool is already converted in block tree and there are a couple others are likely to follow including btrfs io workers. - WQ_UNBOUND's ability to bind to multiple worker pools is also used to make it NUMA-aware. Because there's no association between work item issuer and the specific worker assigned to execute it, before this change, using unbound workqueue led to unnecessary cross-node bouncing and it couldn't be helped by autonuma as it requires tasks to have implicit node affinity and workers are assigned randomly. After these changes, an unbound workqueue now binds to multiple NUMA-affine worker pools so that queued work items are executed in the same node. This is turned on by default but can be disabled system-wide or for individual workqueues. Crypto was requesting NUMA affinity as encrypting data across different nodes can contribute noticeable overhead and doing it per-cpu was too limiting for certain cases and IO throughput could be bottlenecked by one CPU being fully occupied while others have idle cycles. While the new features required a lot of changes including restructuring locking, it didn't complicate the execution paths much. The unbound workqueue handling is now closer to per-cpu ones and the new features are implemented by simply associating a workqueue with different sets of backend worker pools without changing queue, execution or flush paths. As such, even though the amount of change is very high, I feel relatively safe in that it isn't likely to cause subtle issues with basic correctness of work item execution and handling. If something is wrong, it's likely to show up as being associated with worker pools with the wrong attributes or OOPS while workqueue attributes are being changed or during CPU hotplug. While this creates more backend worker pools, it doesn't add too many more workers unless, of course, there are many workqueues with unique combinations of attributes. Assuming everything else is the same, NUMA awareness costs an extra worker pool per NUMA node with online CPUs. There are also a couple things which are being routed outside the workqueue tree. - block tree pulled in workqueue for-3.10 so that writeback worker pool can be converted to unbound workqueue with sysfs control exposed. This simplifies the code, makes writeback workers NUMA-aware and allows tuning nice level and CPU affinity via sysfs. - The conversion to workqueue means that there's no 1:1 association between a specific worker, which makes writeback folks unhappy as they want to be able to tell which filesystem caused a problem from backtrace on systems with many filesystems mounted. This is resolved by allowing work items to set debug info string which is printed when the task is dumped. As this change involves unifying implementations of dump_stack() and friends in arch codes, it's being routed through Andrew's -mm tree." * 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (84 commits) workqueue: use kmem_cache_free() instead of kfree() workqueue: avoid false negative WARN_ON() in destroy_workqueue() workqueue: update sysfs interface to reflect NUMA awareness and a kernel param to disable NUMA affinity workqueue: implement NUMA affinity for unbound workqueues workqueue: introduce put_pwq_unlocked() workqueue: introduce numa_pwq_tbl_install() workqueue: use NUMA-aware allocation for pool_workqueues workqueue: break init_and_link_pwq() into two functions and introduce alloc_unbound_pwq() workqueue: map an unbound workqueues to multiple per-node pool_workqueues workqueue: move hot fields of workqueue_struct to the end workqueue: make workqueue->name[] fixed len workqueue: add workqueue->unbound_attrs workqueue: determine NUMA node of workers accourding to the allowed cpumask workqueue: drop 'H' from kworker names of unbound worker pools workqueue: add wq_numa_tbl_len and wq_numa_possible_cpumask[] workqueue: move pwq_pool_locking outside of get/put_unbound_pool() workqueue: fix memory leak in apply_workqueue_attrs() workqueue: fix unbound workqueue attrs hashing / comparison workqueue: fix race condition in unbound workqueue free path workqueue: remove pwq_lock which is no longer used ... -
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds authored
Pull async update from Tejun Heo: "This contains three cleanup patches for async from Lai. All three patches are essentially cosmetic." * 'for-3.10-async' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: async: rename and redefine async_func_ptr async: remove unused @node from struct async_domain async: simplify lowest_in_progress()
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpuLinus Torvalds authored
Pull percpu patch from Tejun Heo: "A puny pull request for percpu. We were expecting more cleanup patches but didn't happen this time, so just a single patch adding documentation from Christoph." * 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: add documentation on this_cpu operations
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Akinobu Mita authored
Commit 496f2f93 ("random32: rename random32 to prandom") renamed random32() and srandom32() to prandom_u32() and prandom_seed() respectively. net_random() and net_srandom() need to be redefined with prandom_* in order to finish the naming transition. While I'm at it, enclose macro argument of net_srandom() with parenthesis. Signed-off-by:
Akinobu Mita <akinobu.mita@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
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Akinobu Mita authored
Remove duplicate statements by using do-while loop instead of while loop. - A; - while (e) { + do { A; - } + } while (e); Signed-off-by: -
Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
Trond Myklebust <Trond.Myklebust@netapp.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
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Akinobu Mita authored
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by:
H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by:
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Akinobu Mita authored
pageattr-test calls srandom32() once every test iteration. But calling srandom32() after late_initcalls is not meaningfull. Because the random states for random32() is mixed by good random numbers in late_initcall prandom_reseed(). So this removes the call to srandom32(). Signed-off-by:
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Akinobu Mita authored
Use prandom_bytes() to generate 16 bytes of pseudo-random bytes. Signed-off-by:
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Akinobu Mita authored
Use prandom_bytes() to generate random bytes for test data. Signed-off-by:
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Jeff Layton authored
Signed-off-by:
Jeff Layton <jlayton@redhat.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Sridhar Samudrala <sri@us.ibm.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
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Jeff Layton authored
Signed-off-by:
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Jeff Layton authored
Signed-off-by:
"J. Bruce Fields" <bfields@fieldses.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
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Jeff Layton authored
Signed-off-by:
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Jeff Layton authored
Signed-off-by:
Tejun Heo <tj@kernel.org> Cc: Steve Wise <swise@opengridcomputing.com> Cc: Tom Tucker <tom@opengridcomputing.com> Signed-off-by:
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Jeff Layton authored
As Tejun points out, there are several users of the IDR facility that attempt to use it in a cyclic fashion. These users are likely to see -ENOSPC errors after the counter wraps one or more times however. This patchset adds a new idr_alloc_cyclic routine and converts several of these users to it. Many of these users are in obscure parts of the kernel, and I don't have a good way to test some of them. The change is pretty straightforward though, so hopefully it won't be an issue. There is one other cyclic user of idr_alloc that I didn't touch in ipc/util.c. That one is doing some strange stuff that I didn't quite understand, but it looks like it should probably be converted later somehow. This patch: Thus spake Tejun Heo: Ooh, BTW, the cyclic allocation is broken. It's prone to -ENOSPC after the first wraparound. There are several cyclic users in the kernel and I think it probably would be best to implement cyclic support in idr. This patch does that by adding new idr_alloc_cyclic function that such users in the kernel can use. With this, there's no need for a caller to keep track of the last value used as that's now tracked internally. This should prevent the ENOSPC problems that can hit when the "last allocated" counter exceeds INT_MAX. Later patches will convert existing cyclic users to the new interface. Signed-off-by: -
Namjae Jeon authored
Add descriptions about 'stale_rw' and 'nostale_ro' nfs options in filesystem/vfat.txt Signed-off-by:
Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by:
Ravishankar N <ravi.n1@samsung.com> Signed-off-by:
Amit Sahrawat <a.sahrawat@samsung.com> Acked-by:
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Acked-by:
Rob Landley <rob@landley.net> Signed-off-by:
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Namjae Jeon authored
This patch enables rebuilding of directory inodes which are not present in the cache.This is done by traversing the disk clusters to find the directory entry of the parent directory and using its i_pos to build the inode. The traversal is done by fat_scan_logstart() which is similar to fat_scan() but matches i_pos values instead of names.fat_scan_logstart() needs an inode parameter to work, for which a dummy inode is created by it's caller fat_rebuild_parent(). This dummy inode is destroyed after the traversal completes. All this is done only if the nostale_ro nfs mount option is specified. Signed-off-by:
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