Kernel/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-01-09 23:00:21 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

fix 1 mysterious divide error

Browse Source 
fix 3 NULL dereference bugs in writeback tracing, on SD card removal w/o umount
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.11 (GNU/Linux)
 
 iQIcBAABAgAGBQJPNI/ZAAoJECvKgwp+S8JaXNsP/3UwYM4R/bIqjsGSEr8mpxzs
 L/9hq85Vql+HDIZ0QT2Zj8aYcF2iYhjxrrVGVjNmINY3bSvniqtrZ6oCejdj7wqR
 vb2ECC3csUnvUbbewCOM4EaowU2CoANhO5xZeDzOu9SnYfMPuxRzjFlxU5WehJm1
 5dKcCtbaO9Bleo5aZyr2AAaZPgE2lG7Hrvk8HghPhEw7ZBtO1Pc3iVegEhIvRiZR
 tUNTCwxE7QV1GehTUTgGpJWNL4qzrbyiqm/Vg+yI27l13IPn6mb/qfe7eHDFUTCb
 Ey6oeojhmmv0Kgc7b38/0U6q1QNL8x+zJP3J21wMmYqn2DtkLgZkI4TAcmBZwwHi
 rGvrwQESzTpiuhdXxQEOQpmrd8IvTmiFQK+IZzJ3uUA197ROdxyWLmdbbMZvsLym
 8rtC+WNR0IJmPmnWNl1pj2df8YmtWkAGLaw2RMj4RFz3AcXBRurAOrCVG8Lk8ptH
 pFS0n4W3ScuTrZFy1jXYjpVumeIAuWJ/ScPJZhVsDJmssZWv4ZNr/X+OExq0z3dJ
 g9IBJ64q1zJiD5gSs2+iXmBTEHP6lpap9hY9WjApep7RuDsM9+o78oVEJcGdXbRM
 StFJoFdyOrsIR0cuo4yd+Lp/1ZpqP2ES++itW2PA96RXAuP/4R040xXqK/qMEczW
 XfCHqpOIqpCF7lxt9bcc
 =shjO
 -----END PGP SIGNATURE-----

Merge tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux

fix 1 mysterious divide error
fix 3 NULL dereference bugs in writeback tracing, on SD card removal w/o umount

* tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: fix dereferencing NULL bdi->dev on trace_writeback_queue
  lib: proportion: lower PROP_MAX_SHIFT to 32 on 64-bit kernel
  writeback: fix NULL bdi->dev in trace writeback_single_inode
  backing-dev: fix wakeup timer races with bdi_unregister()
This commit is contained in:
Linus Torvalds 2012-02-10 09:05:52 -08:00
commit af5feae3d7
4 changed files with 35 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
fs/fs-writeback.c
View File

@ -52,14 +52,6 @@ struct wb_writeback_work {
struct completion *done; /* set if the caller waits */
};
/*
* Include the creation of the trace points after defining the
* wb_writeback_work structure so that the definition remains local to this
* file.
*/
#define CREATE_TRACE_POINTS
#include <trace/events/writeback.h>
/*
* We don't actually have pdflush, but this one is exported though /proc...
*/
@ -92,6 +84,14 @@ static inline struct inode *wb_inode(struct list_head *head)
return list_entry(head, struct inode, i_wb_list);
}
/*
* Include the creation of the trace points after defining the
* wb_writeback_work structure and inline functions so that the definition
* remains local to this file.
*/
#define CREATE_TRACE_POINTS
#include <trace/events/writeback.h>
/* Wakeup flusher thread or forker thread to fork it. Requires bdi->wb_lock. */
static void bdi_wakeup_flusher(struct backing_dev_info *bdi)
{

4
include/linux/proportions.h
View File

@ -81,7 +81,11 @@ void prop_inc_percpu(struct prop_descriptor *pd, struct prop_local_percpu *pl)
* Limit the time part in order to ensure there are some bits left for the
* cycle counter and fraction multiply.
*/
#if BITS_PER_LONG == 32
#define PROP_MAX_SHIFT (3*BITS_PER_LONG/4)
#else
#define PROP_MAX_SHIFT (BITS_PER_LONG/2)
#endif
#define PROP_FRAC_SHIFT (BITS_PER_LONG - PROP_MAX_SHIFT - 1)
#define PROP_FRAC_BASE (1UL << PROP_FRAC_SHIFT)

7
include/trace/events/writeback.h
View File

@ -47,7 +47,10 @@ DECLARE_EVENT_CLASS(writeback_work_class,
__field(int, reason)
),
TP_fast_assign(
strncpy(__entry->name, dev_name(bdi->dev), 32);
struct device *dev = bdi->dev;
if (!dev)
dev = default_backing_dev_info.dev;
strncpy(__entry->name, dev_name(dev), 32);
__entry->nr_pages = work->nr_pages;
__entry->sb_dev = work->sb ? work->sb->s_dev : 0;
__entry->sync_mode = work->sync_mode;
@ -426,7 +429,7 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template,
TP_fast_assign(
strncpy(__entry->name,
dev_name(inode->i_mapping->backing_dev_info->dev), 32);
dev_name(inode_to_bdi(inode)->dev), 32);
__entry->ino = inode->i_ino;
__entry->state = inode->i_state;
__entry->dirtied_when = inode->dirtied_when;

23
mm/backing-dev.c
View File

@ -318,7 +318,7 @@ static void wakeup_timer_fn(unsigned long data)
if (bdi->wb.task) {
trace_writeback_wake_thread(bdi);
wake_up_process(bdi->wb.task);
} else {
} else if (bdi->dev) {
/*
* When bdi tasks are inactive for long time, they are killed.
* In this case we have to wake-up the forker thread which
@ -584,6 +584,8 @@ EXPORT_SYMBOL(bdi_register_dev);
*/
static void bdi_wb_shutdown(struct backing_dev_info *bdi)
{
struct task_struct *task;
if (!bdi_cap_writeback_dirty(bdi))
return;
@ -602,8 +604,13 @@ static void bdi_wb_shutdown(struct backing_dev_info *bdi)
* Finally, kill the kernel thread. We don't need to be RCU
* safe anymore, since the bdi is gone from visibility.
*/
if (bdi->wb.task)
kthread_stop(bdi->wb.task);
spin_lock_bh(&bdi->wb_lock);
task = bdi->wb.task;
bdi->wb.task = NULL;
spin_unlock_bh(&bdi->wb_lock);
if (task)
kthread_stop(task);
}
/*
@ -623,7 +630,9 @@ static void bdi_prune_sb(struct backing_dev_info *bdi)
void bdi_unregister(struct backing_dev_info *bdi)
{
if (bdi->dev) {
struct device *dev = bdi->dev;
if (dev) {
bdi_set_min_ratio(bdi, 0);
trace_writeback_bdi_unregister(bdi);
bdi_prune_sb(bdi);
@ -632,8 +641,12 @@ void bdi_unregister(struct backing_dev_info *bdi)
if (!bdi_cap_flush_forker(bdi))
bdi_wb_shutdown(bdi);
bdi_debug_unregister(bdi);
device_unregister(bdi->dev);
spin_lock_bh(&bdi->wb_lock);
bdi->dev = NULL;
spin_unlock_bh(&bdi->wb_lock);
device_unregister(dev);
}
}
EXPORT_SYMBOL(bdi_unregister);