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path: root/fs/xfs/xfs_sysfs.c
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2017-06-27xfs: replace log_badcrc_factor knob with error injection tagBrian Foster1-36/+0
Now that error injection tags support dynamic frequency adjustment, replace the debug mode sysfs knob that controls log record CRC error injection with an error injection tag. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-06-27xfs: convert drop_writes to use the errortag mechanismDarrick J. Wong1-42/+0
We now have enhanced error injection that can control the frequency with which errors happen, so convert drop_writes to use this. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2017-06-19xfs: define bug_on_assert debug mode sysfs tunableBrian Foster1-0/+33
In DEBUG mode, assert failures unconditionally trigger a kernel BUG. This is useful in diagnostic situations to panic a system and collect detailed state information at the time of a failure. This can also cause problems in cases where DEBUG mode code is desired but it is preferable not trigger kernel BUGs on assert failure. For example, during development of new code or during certain xfstests tests that intentionally cause corruption and test the kernel for survival (but otherwise may expect to trigger assert failures). To provide additional flexibility, create the <sysfs>/fs/xfs/debug/bug_on_assert tunable to configure assert failure behavior at runtime. This tunable is only available in DEBUG mode and is enabled by default to preserve existing default behavior. When disabled, assert failures in DEBUG mode result in kernel warnings. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-02-16xfs: resurrect debug mode drop buffered writes mechanismBrian Foster1-7/+7
A debug mode write failure mechanism was introduced to XFS in commit 801cc4e17a ("xfs: debug mode forced buffered write failure") to facilitate targeted testing of delalloc indirect reservation management from userspace. This code was subsequently rendered ineffective by the move to iomap based buffered writes in commit 68a9f5e700 ("xfs: implement iomap based buffered write path"). This likely went unnoticed because the associated userspace code had not made it into xfstests. Resurrect this mechanism to facilitate effective indlen reservation testing from xfstests. The move to iomap based buffered writes relocated the hook this mechanism needs to return write failure from XFS to generic code. The failure trigger must remain in XFS. Given that limitation, convert this from a write failure mechanism to one that simply drops writes without returning failure to userspace. Rename all "fail_writes" references to "drop_writes" to illustrate the point. This is more hacky than preferred, but still triggers the XFS error handling behavior required to drive the indlen tests. This is only available in DEBUG mode and for testing purposes only. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-03xfs: fix max_retries _show and _store functionsCarlos Maiolino1-2/+2
max_retries _show and _store functions should test against cfg->max_retries, not cfg->retry_timeout Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2016-10-20xfs: add some 'static' annotationsEric Biggers1-2/+2
sparse reported that several variables and a function were not forward-declared anywhere and therefore should be 'static'. Found with sparse by running 'make C=2 CF=-D__CHECK_ENDIAN__ fs/xfs/' Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-14xfs: normalize "infinite" retries in error configsEric Sandeen1-12/+35
As it stands today, the "fail immediately" vs. "retry forever" values for max_retries and retry_timeout_seconds in the xfs metadata error configurations are not consistent. A retry_timeout_seconds of 0 means "retry forever," but a max_retries of 0 means "fail immediately." retry_timeout_seconds < 0 is disallowed, while max_retries == -1 means "retry forever." Make this consistent across the error configs, such that a value of 0 means "fail immediately" (i.e. wait 0 seconds, or retry 0 times), and a value of -1 always means "retry forever." This makes retry_timeout a signed long to accommodate the -1, even though it stores jiffies. Given our limit of a 1 day maximum timeout, this should be sufficient even at much higher HZ values than we have available today. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20xfs: fix xfs_error_get_cfg for negative errnosEric Sandeen1-0/+3
xfs_error_get_cfg() is called with bp->b_error as an arg, which is negative, so the switch statement won't ever find any matches. This results in only the default error handler having any effect, as EIO/ENOSPC/ENODEV get ignored due to the wrong sign. It seems simplest to always flip the error sign to positive, so that we can handle either negative errors in bp->b_error, or possibly a positive errno via something like xfs_error_get_cfg(EIO) - this future-proofs the function. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-05-18xfs: add "fail at unmount" error handling configurationCarlos Maiolino1-0/+46
If we take "retry forever" literally on metadata IO errors, we can hang at unmount, once it retries those writes forever. This is the default behavior, unfortunately. Add an error configuration option for this behavior and default it to "fail" so that an unmount will trigger actuall errors, a shutdown and allow the unmount to succeed. It will be noisy, though, as it will log the errors and shutdown that occurs. To fix this, we need to mark the filesystem as being in the process of unmounting. Do this with a mount flag that is added at the appropriate time (i.e. before the blocking AIL sync). We also need to add this flag if mount fails after the initial phase of log recovery has been run. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-05-18xfs: add configuration handlers for specific errorsCarlos Maiolino1-1/+21
now most of the infrastructure is in place, we can start adding support for configuring specific errors such as ENODEV, ENOSPC, EIO, etc. Add these error configurations and configure them all to have appropriate behaviours. That is, all will be configured to retry forever by default, except for ENODEV, which is an unrecoverable error, so it will be configured to not retry on error Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-05-18xfs: add configuration of error failure speedCarlos Maiolino1-4/+77
On reception of an error, we can fail immediately, perform some bound amount of retries or retry indefinitely. The current behaviour we have is to retry forever. However, we'd like the ability to choose how long the filesystem should try after an error, it can either fail immediately, retry a few times, or retry forever. This is implemented by using max_retries sysfs attribute, to hold the amount of times we allow the filesystem to retry after an error. Being -1 a special case where the filesystem will retry indefinitely. Add both a maximum retry count and a retry timeout so that we can bound by time and/or physical IO attempts. Finally, plumb these into xfs_buf_iodone error processing so that the error behaviour follows the selected configuration. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-05-18xfs: introduce table-based init for error behaviorsCarlos Maiolino1-12/+60
Before we start expanding the number of error classes and errors we can configure behaviour for, we need a simple and clear way to define the default behaviour that we initialized each mount with. Introduce a table based method for keeping the initial configuration in, and apply that to the existing initialization code. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-05-18xfs: add configurable error support to metadata buffersCarlos Maiolino1-0/+17
With the error configuration handle for async metadata write errors in place, we can now add initial support to the IO error processing in xfs_buf_iodone_error(). Add an infrastructure function to look up the configuration handle, and rearrange the error handling to prepare the way for different error handling conigurations to be used. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-05-18xfs: introduce metadata IO error classCarlos Maiolino1-0/+34
Now we have the basic infrastructure, add the first error class so we can build up the infrastructure in a meaningful way. Add the metadata async write IO error class and sysfs entry, and introduce a default configuration that matches the existing "retry forever" behavior for async write metadata buffers. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-05-18xfs: configurable error behavior via sysfsCarlos Maiolino1-1/+52
We need to be able to change the way XFS behaviours in error conditions depending on the type of underlying storage. This is necessary for handling non-traditional block devices with extended error cases, such as thin provisioned devices that can return ENOSPC as an IO error. Introduce the basic sysfs infrastructure needed to define and configure error behaviours. This is done to be generic enough to extend to configuring behaviour in other error conditions, such as ENOMEM, which also has different desired behaviours according to machine configuration. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-03-15xfs: debug mode forced buffered write failureBrian Foster1-10/+68
Add a DEBUG mode-only sysfs knob to enable forced buffered write failure. An additional side effect of this mode is brute force killing of delayed allocation blocks in the range of the write. The latter is the prime motiviation behind this patch, as userspace test infrastructure requires a reliable mechanism to create and split delalloc extents without causing extent conversion. Certain fallocate operations (i.e., zero range) were used for this in the past, but the implementations have changed such that delalloc extents are flushed and converted to real blocks, rendering the test useless. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-01-05xfs: debug mode log record crc error injectionBrian Foster1-0/+36
XFS now uses CRC verification over a limited section of the log to detect torn writes prior to a crash. This is difficult to test directly due to the timing and hardware requirements to cause a short write. Add a mechanism to inject CRC errors into log records to facilitate testing torn write detection during log recovery. This mechanism is dangerous and can result in filesystem corruption. Thus, it is only available in DEBUG mode for testing/development purposes. Set a non-zero value to the following sysfs entry to enable error injection: /sys/fs/xfs/<dev>/log/log_badcrc_factor Once enabled, XFS intentionally writes an invalid CRC to a log record at some random point in the future based on the provided frequency. The filesystem immediately shuts down once the record has been written to the physical log to prevent metadata writeback (e.g., AIL insertion) once the log write completes. This helps reasonably simulate a torn write to the log as the affected record must be safe to discard. The next mount after the intentional shutdown requires log recovery and should detect and recover from the torn write. Note again that this _will_ result in data loss or worse. For testing and development purposes only! Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-10-12xfs: pass xfsstats structures to handlers and macrosBill O'Donnell1-2/+14
This patch is the next step toward per-fs xfs stats. The patch makes the show and clear routines able to handle any stats structure associated with a kobject. Instead of a single global xfsstats structure, add kobject and a pointer to a per-cpu struct xfsstats. Modify the macros that manipulate the stats accordingly: XFS_STATS_INC, XFS_STATS_DEC, and XFS_STATS_ADD now access xfsstats->xs_stats. The sysfs functions need to get from the kobject back to the xfsstats structure which contains it, and pass the pointer to the ->xs_stats percpu structure into the show & clear routines. Signed-off-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-10-12xfs: consolidate sysfs opsBill O'Donnell1-119/+63
As a part of the series to move xfs global stats from procfs to sysfs, this patch consolidates the sysfs ops functions and removes redundancy. Signed-off-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-10-12xfs: create global stats and stats_clear in sysfsBill O'Donnell1-0/+75
Currently, xfs global stats are in procfs. This patch introduces (replicates) the global stats in sysfs. Additionally a stats_clear file is introduced in sysfs. Signed-off-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-09-09xfs: export log_recovery_delay to delay mount time log recoveryBrian Foster1-0/+31
XFS log recovery has been discovered to have race conditions with buffers when I/O errors occur. External tools are available to simulate I/O errors to XFS, but this alone is not sufficient for testing log recovery. XFS unconditionally resets the inactive region of the log prior to log recovery to avoid confusion over processing any partially written log records that might have been written before an unclean shutdown. Therefore, unconditional write I/O failures at mount time are caught by the reset sequence rather than log recovery and hinder the ability to test the latter. The device-mapper dm-flakey module uses an up/down timer to define a cycle for when to fail I/Os. Create a pre log recovery delay tunable that can be used to coordinate XFS log recovery with I/O errors simulated by dm-flakey. This facilitates coordination in userspace that allows the reset of stale log blocks to succeed and writes due to log recovery to fail. For example, define a dm-flakey instance with an uptime long enough to allow log reset to succeed and a log recovery delay long enough to allow the dm-flakey uptime to expire. The 'log_recovery_delay' sysfs tunable is exported under /sys/fs/xfs/debug and is only enabled for kernels compiled in XFS debug mode. The value is exported in units of seconds and allows for a delay of up to 60 seconds. Note that this is for XFS debug and test instrumentation purposes only and should not be used by applications. No delay is enabled by default. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-09-09xfs: add debug sysfs attribute setBrian Foster1-0/+43
Create a top-level debug directory for global debug sysfs attributes. This directory is added and removed on XFS module initialization and removal respectively for DEBUG mode kernels only. It typically resides at /sys/fs/xfs/debug. It is located at the top level of the xfs sysfs hierarchy as attributes might define global behavior or behavior that must be configured before an xfs mount is available (e.g., log recovery behavior). Define the global debug kobject that represents the debug sysfs directory and add generic attribute show/store helpers to support future attributes. No debug attributes are exported as of yet. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-07-15xfs: add log attributes for log lsn and grant head dataBrian Foster1-0/+64
Create log attributes to export the current runtime state of the log to sysfs. Note that the filesystem should be frozen for consistency across attributes. The following per-mount attributes are created: log_head_lsn, log_tail_lsn, reserve_grant_head and write_grant_head. These represent the physical log head, tail and reserve and write grant heads respectively. Attribute values are exported in the following format: "cycle:[block,byte]" ... where cycle represents the log cycle and [block,bytes] represents either the basic block or byte offset of the log, depending on the attribute. Log sequence number (LSN) values are encoded in basic blocks and grant heads are encoded in bytes. All values are in decimal format. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-07-15xfs: add xlog sysfs kobject and attribute handlersBrian Foster1-0/+52
Embed a kobject into the xfs log data structure (xlog). This creates a 'log' subdirectory for every XFS mount instance in sysfs. The lifecycle of the log kobject is tied to the lifecycle of the log. Also define a set of generic attribute handlers associated with the log kobject in preparation for the addition of attributes. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-07-15xfs: add xfs_mount sysfs kobjectBrian Foster1-0/+49
Embed a base kobject into xfs_mount. This creates a kobject associated with each XFS mount and a subdirectory in sysfs with the name of the filesystem. The subdirectory lifecycle matches that of the mount. Also add the new xfs_sysfs.[c,h] source files with some XFS sysfs infrastructure to facilitate attribute creation. Note that there are currently no attributes exported as part of the xfs_mount kobject. It exists solely to serve as a per-mount container for child objects. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>