linux/fs/xfs/xfs_sysctl.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2001-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
xfs: prevent NMI timeouts in cmn_err We currently have a global error message buffer in cmn_err that is protected by a spin lock that disables interrupts. Recently there have been reports of NMI timeouts occurring when the console is being flooded by SCSI error reports due to cmn_err() getting stuck trying to print to the console while holding this lock (i.e. with interrupts disabled). The NMI watchdog is seeing this CPU as non-responding and so is triggering a panic. While the trigger for the reported case is SCSI errors, pretty much anything that spams the kernel log could cause this to occur. Realistically the only reason that we have the intemediate message buffer is to prepend the correct kernel log level prefix to the log message. The only reason we have the lock is to protect the global message buffer and the only reason the message buffer is global is to keep it off the stack. Hence if we can avoid needing a global message buffer we avoid needing the lock, and we can do this with a small amount of cleanup and some preprocessor tricks: 1. clean up xfs_cmn_err() panic mask functionality to avoid needing debug code in xfs_cmn_err() 2. remove the couple of "!" message prefixes that still exist that the existing cmn_err() code steps over. 3. redefine CE_* levels directly to KERN_* 4. redefine cmn_err() and friends to use printk() directly via variable argument length macros. By doing this, we can completely remove the cmn_err() code and the lock that is causing the problems, and rely solely on printk() serialisation to ensure that we don't get garbled messages. A series of followup patches is really needed to clean up all the cmn_err() calls and related messages properly, but that results in a series that is not easily back portable to enterprise kernels. Hence this initial fix is only to address the direct problem in the lowest impact way possible. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-12 08:35:42 +08:00
#include "xfs_error.h"
static struct ctl_table_header *xfs_table_header;
#ifdef CONFIG_PROC_FS
STATIC int
xfs_stats_clear_proc_handler(
struct ctl_table *ctl,
int write,
void *buffer,
size_t *lenp,
loff_t *ppos)
{
int ret, *valp = ctl->data;
ret = proc_dointvec_minmax(ctl, write, buffer, lenp, ppos);
if (!ret && write && *valp) {
xfs_stats_clearall(xfsstats.xs_stats);
xfs_stats_clear = 0;
}
return ret;
}
xfs: prevent NMI timeouts in cmn_err We currently have a global error message buffer in cmn_err that is protected by a spin lock that disables interrupts. Recently there have been reports of NMI timeouts occurring when the console is being flooded by SCSI error reports due to cmn_err() getting stuck trying to print to the console while holding this lock (i.e. with interrupts disabled). The NMI watchdog is seeing this CPU as non-responding and so is triggering a panic. While the trigger for the reported case is SCSI errors, pretty much anything that spams the kernel log could cause this to occur. Realistically the only reason that we have the intemediate message buffer is to prepend the correct kernel log level prefix to the log message. The only reason we have the lock is to protect the global message buffer and the only reason the message buffer is global is to keep it off the stack. Hence if we can avoid needing a global message buffer we avoid needing the lock, and we can do this with a small amount of cleanup and some preprocessor tricks: 1. clean up xfs_cmn_err() panic mask functionality to avoid needing debug code in xfs_cmn_err() 2. remove the couple of "!" message prefixes that still exist that the existing cmn_err() code steps over. 3. redefine CE_* levels directly to KERN_* 4. redefine cmn_err() and friends to use printk() directly via variable argument length macros. By doing this, we can completely remove the cmn_err() code and the lock that is causing the problems, and rely solely on printk() serialisation to ensure that we don't get garbled messages. A series of followup patches is really needed to clean up all the cmn_err() calls and related messages properly, but that results in a series that is not easily back portable to enterprise kernels. Hence this initial fix is only to address the direct problem in the lowest impact way possible. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-12 08:35:42 +08:00
STATIC int
xfs_panic_mask_proc_handler(
struct ctl_table *ctl,
int write,
void *buffer,
size_t *lenp,
loff_t *ppos)
xfs: prevent NMI timeouts in cmn_err We currently have a global error message buffer in cmn_err that is protected by a spin lock that disables interrupts. Recently there have been reports of NMI timeouts occurring when the console is being flooded by SCSI error reports due to cmn_err() getting stuck trying to print to the console while holding this lock (i.e. with interrupts disabled). The NMI watchdog is seeing this CPU as non-responding and so is triggering a panic. While the trigger for the reported case is SCSI errors, pretty much anything that spams the kernel log could cause this to occur. Realistically the only reason that we have the intemediate message buffer is to prepend the correct kernel log level prefix to the log message. The only reason we have the lock is to protect the global message buffer and the only reason the message buffer is global is to keep it off the stack. Hence if we can avoid needing a global message buffer we avoid needing the lock, and we can do this with a small amount of cleanup and some preprocessor tricks: 1. clean up xfs_cmn_err() panic mask functionality to avoid needing debug code in xfs_cmn_err() 2. remove the couple of "!" message prefixes that still exist that the existing cmn_err() code steps over. 3. redefine CE_* levels directly to KERN_* 4. redefine cmn_err() and friends to use printk() directly via variable argument length macros. By doing this, we can completely remove the cmn_err() code and the lock that is causing the problems, and rely solely on printk() serialisation to ensure that we don't get garbled messages. A series of followup patches is really needed to clean up all the cmn_err() calls and related messages properly, but that results in a series that is not easily back portable to enterprise kernels. Hence this initial fix is only to address the direct problem in the lowest impact way possible. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-12 08:35:42 +08:00
{
int ret, *valp = ctl->data;
ret = proc_dointvec_minmax(ctl, write, buffer, lenp, ppos);
if (!ret && write) {
xfs_panic_mask = *valp;
#ifdef DEBUG
xfs_panic_mask |= (XFS_PTAG_SHUTDOWN_CORRUPT | XFS_PTAG_LOGRES);
#endif
}
return ret;
}
#endif /* CONFIG_PROC_FS */
STATIC int
xfs_deprecated_dointvec_minmax(
struct ctl_table *ctl,
int write,
void *buffer,
size_t *lenp,
loff_t *ppos)
{
if (write) {
printk_ratelimited(KERN_WARNING
"XFS: %s sysctl option is deprecated.\n",
ctl->procname);
}
return proc_dointvec_minmax(ctl, write, buffer, lenp, ppos);
}
static struct ctl_table xfs_table[] = {
{
.procname = "irix_sgid_inherit",
.data = &xfs_params.sgid_inherit.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = xfs_deprecated_dointvec_minmax,
.extra1 = &xfs_params.sgid_inherit.min,
.extra2 = &xfs_params.sgid_inherit.max
},
{
.procname = "irix_symlink_mode",
.data = &xfs_params.symlink_mode.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = xfs_deprecated_dointvec_minmax,
.extra1 = &xfs_params.symlink_mode.min,
.extra2 = &xfs_params.symlink_mode.max
},
{
.procname = "panic_mask",
.data = &xfs_params.panic_mask.val,
.maxlen = sizeof(int),
.mode = 0644,
xfs: prevent NMI timeouts in cmn_err We currently have a global error message buffer in cmn_err that is protected by a spin lock that disables interrupts. Recently there have been reports of NMI timeouts occurring when the console is being flooded by SCSI error reports due to cmn_err() getting stuck trying to print to the console while holding this lock (i.e. with interrupts disabled). The NMI watchdog is seeing this CPU as non-responding and so is triggering a panic. While the trigger for the reported case is SCSI errors, pretty much anything that spams the kernel log could cause this to occur. Realistically the only reason that we have the intemediate message buffer is to prepend the correct kernel log level prefix to the log message. The only reason we have the lock is to protect the global message buffer and the only reason the message buffer is global is to keep it off the stack. Hence if we can avoid needing a global message buffer we avoid needing the lock, and we can do this with a small amount of cleanup and some preprocessor tricks: 1. clean up xfs_cmn_err() panic mask functionality to avoid needing debug code in xfs_cmn_err() 2. remove the couple of "!" message prefixes that still exist that the existing cmn_err() code steps over. 3. redefine CE_* levels directly to KERN_* 4. redefine cmn_err() and friends to use printk() directly via variable argument length macros. By doing this, we can completely remove the cmn_err() code and the lock that is causing the problems, and rely solely on printk() serialisation to ensure that we don't get garbled messages. A series of followup patches is really needed to clean up all the cmn_err() calls and related messages properly, but that results in a series that is not easily back portable to enterprise kernels. Hence this initial fix is only to address the direct problem in the lowest impact way possible. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-12 08:35:42 +08:00
.proc_handler = xfs_panic_mask_proc_handler,
.extra1 = &xfs_params.panic_mask.min,
.extra2 = &xfs_params.panic_mask.max
},
{
.procname = "error_level",
.data = &xfs_params.error_level.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &xfs_params.error_level.min,
.extra2 = &xfs_params.error_level.max
},
{
.procname = "xfssyncd_centisecs",
.data = &xfs_params.syncd_timer.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &xfs_params.syncd_timer.min,
.extra2 = &xfs_params.syncd_timer.max
},
{
.procname = "inherit_sync",
.data = &xfs_params.inherit_sync.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &xfs_params.inherit_sync.min,
.extra2 = &xfs_params.inherit_sync.max
},
{
.procname = "inherit_nodump",
.data = &xfs_params.inherit_nodump.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &xfs_params.inherit_nodump.min,
.extra2 = &xfs_params.inherit_nodump.max
},
{
.procname = "inherit_noatime",
.data = &xfs_params.inherit_noatim.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &xfs_params.inherit_noatim.min,
.extra2 = &xfs_params.inherit_noatim.max
},
{
.procname = "inherit_nosymlinks",
.data = &xfs_params.inherit_nosym.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &xfs_params.inherit_nosym.min,
.extra2 = &xfs_params.inherit_nosym.max
},
{
.procname = "rotorstep",
.data = &xfs_params.rotorstep.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &xfs_params.rotorstep.min,
.extra2 = &xfs_params.rotorstep.max
},
{
.procname = "inherit_nodefrag",
.data = &xfs_params.inherit_nodfrg.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &xfs_params.inherit_nodfrg.min,
.extra2 = &xfs_params.inherit_nodfrg.max
},
[XFS] Concurrent Multi-File Data Streams In media spaces, video is often stored in a frame-per-file format. When dealing with uncompressed realtime HD video streams in this format, it is crucial that files do not get fragmented and that multiple files a placed contiguously on disk. When multiple streams are being ingested and played out at the same time, it is critical that the filesystem does not cross the streams and interleave them together as this creates seek and readahead cache miss latency and prevents both ingest and playout from meeting frame rate targets. This patch set creates a "stream of files" concept into the allocator to place all the data from a single stream contiguously on disk so that RAID array readahead can be used effectively. Each additional stream gets placed in different allocation groups within the filesystem, thereby ensuring that we don't cross any streams. When an AG fills up, we select a new AG for the stream that is not in use. The core of the functionality is the stream tracking - each inode that we create in a directory needs to be associated with the directories' stream. Hence every time we create a file, we look up the directories' stream object and associate the new file with that object. Once we have a stream object for a file, we use the AG that the stream object point to for allocations. If we can't allocate in that AG (e.g. it is full) we move the entire stream to another AG. Other inodes in the same stream are moved to the new AG on their next allocation (i.e. lazy update). Stream objects are kept in a cache and hold a reference on the inode. Hence the inode cannot be reclaimed while there is an outstanding stream reference. This means that on unlink we need to remove the stream association and we also need to flush all the associations on certain events that want to reclaim all unreferenced inodes (e.g. filesystem freeze). SGI-PV: 964469 SGI-Modid: xfs-linux-melb:xfs-kern:29096a Signed-off-by: David Chinner <dgc@sgi.com> Signed-off-by: Barry Naujok <bnaujok@sgi.com> Signed-off-by: Donald Douwsma <donaldd@sgi.com> Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Tim Shimmin <tes@sgi.com> Signed-off-by: Vlad Apostolov <vapo@sgi.com>
2007-07-11 09:09:12 +08:00
{
.procname = "filestream_centisecs",
.data = &xfs_params.fstrm_timer.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
[XFS] Concurrent Multi-File Data Streams In media spaces, video is often stored in a frame-per-file format. When dealing with uncompressed realtime HD video streams in this format, it is crucial that files do not get fragmented and that multiple files a placed contiguously on disk. When multiple streams are being ingested and played out at the same time, it is critical that the filesystem does not cross the streams and interleave them together as this creates seek and readahead cache miss latency and prevents both ingest and playout from meeting frame rate targets. This patch set creates a "stream of files" concept into the allocator to place all the data from a single stream contiguously on disk so that RAID array readahead can be used effectively. Each additional stream gets placed in different allocation groups within the filesystem, thereby ensuring that we don't cross any streams. When an AG fills up, we select a new AG for the stream that is not in use. The core of the functionality is the stream tracking - each inode that we create in a directory needs to be associated with the directories' stream. Hence every time we create a file, we look up the directories' stream object and associate the new file with that object. Once we have a stream object for a file, we use the AG that the stream object point to for allocations. If we can't allocate in that AG (e.g. it is full) we move the entire stream to another AG. Other inodes in the same stream are moved to the new AG on their next allocation (i.e. lazy update). Stream objects are kept in a cache and hold a reference on the inode. Hence the inode cannot be reclaimed while there is an outstanding stream reference. This means that on unlink we need to remove the stream association and we also need to flush all the associations on certain events that want to reclaim all unreferenced inodes (e.g. filesystem freeze). SGI-PV: 964469 SGI-Modid: xfs-linux-melb:xfs-kern:29096a Signed-off-by: David Chinner <dgc@sgi.com> Signed-off-by: Barry Naujok <bnaujok@sgi.com> Signed-off-by: Donald Douwsma <donaldd@sgi.com> Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Tim Shimmin <tes@sgi.com> Signed-off-by: Vlad Apostolov <vapo@sgi.com>
2007-07-11 09:09:12 +08:00
.extra1 = &xfs_params.fstrm_timer.min,
.extra2 = &xfs_params.fstrm_timer.max,
},
{
.procname = "speculative_prealloc_lifetime",
.data = &xfs_params.blockgc_timer.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &xfs_params.blockgc_timer.min,
.extra2 = &xfs_params.blockgc_timer.max,
},
{
.procname = "speculative_cow_prealloc_lifetime",
.data = &xfs_params.blockgc_timer.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = xfs_deprecated_dointvec_minmax,
.extra1 = &xfs_params.blockgc_timer.min,
.extra2 = &xfs_params.blockgc_timer.max,
},
/* please keep this the last entry */
#ifdef CONFIG_PROC_FS
{
.procname = "stats_clear",
.data = &xfs_params.stats_clear.val,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = xfs_stats_clear_proc_handler,
.extra1 = &xfs_params.stats_clear.min,
.extra2 = &xfs_params.stats_clear.max
},
#endif /* CONFIG_PROC_FS */
{}
};
int
xfs_sysctl_register(void)
{
xfs_table_header = register_sysctl("fs/xfs", xfs_table);
if (!xfs_table_header)
return -ENOMEM;
return 0;
}
void
xfs_sysctl_unregister(void)
{
unregister_sysctl_table(xfs_table_header);
}