In most cases, when EH is scheduled, all in-flight commands are
aborted causing EH to kick in immediately. However, in some cases
(especially with PMP), it's unclear which commands are affected by the
error condition and although aborting all in-flight commands work, it
isn't optimal and may cause unnecessary disruption. On the other
hand, waiting for in-flight commands to drain themselves can take up
to 30seconds.
This patch implements EH fast drain to handle such situations. It
gives in-flight commands some time to finish up but doesn't wait for
too long. After EH is scheduled, fast drain timer is started and if
no other completion occurs in ATA_EH_FASTDRAIN_INTERVAL all in-flight
commands are aborted. If any completion occurred in the interval, the
port is given another interval to finish up itself.
Currently ATA_EH_FASTDRAIN_INTERVAL is 3 secs which should be enough
for finishing up most commands.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
If SError isn't accessible, EH can't tell whether hotplug has happened
or not. Report SError read failure with AC_ERR_OTHER and schedule
probing with hardreset. This will be mainly useful for PMPs.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
ATA_EHI_HOTPLUGGED is a hint for reset functions indicating the the
port might have gone through hotplug/unplug just before entering EH.
Reset functions modify their behaviors a bit to handle the situation
better - e.g. using longer debouncing delay.
Currently, once HOTPLUG is set, it isn't cleared till the end of EH.
This is unnecessary and makes EH take longer. Clear the HOTPLUGGED
flag after a reset try (successful or not).
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
__ata_ehi_hotplugged() now has no users. Regorganize
ata_ehi_hotplugged() such that a new function ata_ehi_schedule_probe()
deals with scheduling probing. ata_ehi_hotplugged() calls it and
additionally marks hotplug specific flags. ata_ehi_schedule_probe()
will be used laster.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
SCSI scan may fail due to memory allocation failure even if EH is not
in progress. Due to use of GFP_ATOMIC in SCSI scan path, allocation
failure isn't too rare especially while probing multiple devices at
once which is the case when a bunch of devices are connected to PMP.
This patch moves SCSI scan failure detetion logic from
ata_scsi_hotplug() to ata_scsi_scan_host() and implement synchronous
scan behavior. The synchronous path sleeps briefly and repeats SCSI
scan if some devices aren't attached properly. It contains robust
retry loop to minimize the chance of device misdetection during boot
and falls back to async retry if everything fails.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Debouncing failure is a good indicator of basic link problem. Use
-EPIPE to indicate debouncing failure and make ata_eh_reset() invoke
sata_down_spd_limit() if the error occurs during reset.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
sata_down_spd_limit() first reads the current SPD from SStatus and
limit the speed to the lower one of one below the current limit or one
below the current SPD in SStatus. SPD may not be accessible or valid
when SPD down is requested making sata_down_spd_limit() fail when it's
most needed.
This patch makes the current SPD cached after each successful reset
and forces GEN I speed (1.5Gbps) if neither of SStatus or the cached
value is valid, so sata_down_spd_limit() is now guaranteed to lower
the speed limit if lower speed is available.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Make ahci_scr_read/write() handle SCR_NOTIFICATION if the controller
supports it. Also, print "sntf" in the cap line if supported.
While at it, convert eight space into a tab in ahci_print_info().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
ahci_save_initial_config() is responsible for reading, screening the
host CAP register and storing the modified result into hpriv->cap for
the rest of the driver. Move ATA_FLAG_NO_NCQ handling into
ahci_save_initial_config(). It's more consistent this way and the
rest of the driver can always refer to hpriv->cap to determine
configured capability.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Convert ->scr_read/write callbacks to return error code to better
indicate failure. This will help handling of SCR_NOTIFICATION.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
When an NCQ command fails, all commands in flight are aborted and the
offending one is reported using log page 10h. Depending on controller
characteristics and LLD implementation, all commands may appear as
having a device error due to shared TF status making it hard to
determine what's actually going on.
This patch adds AC_ERR_NCQ, marks the command reported by log page 10h
with it and print extra "<F>" after the error report for the command
to help distinguishing the offending command.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Requiring LLDs to format multiple error description messages properly
doesn't work too well. Help LLDs a bit by making ata_ehi_push_desc()
insert ", " on each invocation. __ata_ehi_push_desc() is the raw
version without the automatic separator.
While at it, make ehi_desc interface proper functions instead of
macros.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Separate out sil24_do_softreset() which takes @pmp as its last
argument. This will be used to implement sil24_pmp_softreset().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Separate out sil24_exec_polled_cmd() from sil24_softreset(). This
will be used to implement sil24_pmp_read/write().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Replace sil24_update_tf() to sil24_read_tf() which reads TF into
passed int result TF argument and can read TFs of PMP links. This
will be used by PMP support.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Separate out ahci_do_softreset() which takes @pmp as its last
argument. This will be used to implement ahci_pmp_softreset().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Separate out ahci_exec_polled_cmd() from ahci_softreset(). This will
be used to implement ahci_pmp_read/write(). ahci_exec_polled_cmd()
performs reset_engine before returning if the command fails (times
out). This is to improve robustness.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Separate out stop_engine - CLO - start_engine sequence from
ahci_softreset() and ahci_clo() into ahci_reset_engine() and use it in
ahci_softreset() and ahci_post_internal_cmd(). The function will also
be used to prepare for and clean up after PMP register access
commands.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Use deadline instead of fixed timeout for 1st FIS for SRST to improve
robustness of SRST.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Add @is_cmd to ata_tf_to_fis(). This controls bit 7 of the second
byte which tells the device whether this H2D FIS is for a command or
not. This cleans up ahci a bit and will be used by PMP.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Yay, the first one from Seagate. 3.ALC firmware is okay. This was
reported by Sam Freed on bugzilla bug 8759.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Sam Freed <sam@freed.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Node addition failure is detected by testing return value of
sysfs_addfm_finish() which returns the number of added and removed
nodes. As the function is called as the last step of addition right
on top of error handling block, the if blocks looked like the
following.
if (sysfs_addrm_finish(&acxt))
success handling, usually return;
/* fall through to error handling */
This is the opposite of usual convention in sysfs and makes the code
difficult to understand. This patch inverts the test and makes those
blocks look more like others.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Gabriel C <nix.or.die@googlemail.com>
Cc: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is a subtle bug in sysfs_create_link() failure path. When
symlink creation fails because there's already a node with the same
name, the target sysfs_dirent is put twice - once by failure path of
sysfs_create_link() and once more when the symlink is released.
Fix it by making only the symlink node responsible for putting
target_sd.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Gabriel C <nix.or.die@googlemail.com>
Cc: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
With sysfs_fill_super() converted to use sysfs_get_inode(), there is
no user of sysfs_init_inode() outside of fs/sysfs/inode.c. Make it
static.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
While making sysfs indoes hashed, sysfs root inode was left out. Now
that nlink accounting depends on the inode being on the hash, sysfs
root inode nlink isn't adjusted properly.
Put sysfs root inode on the inode hash by allocating it using
sysfs_get_inode() like other sysfs inodes. While at it, massage
comments a bit.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
KSYM_NAME_LEN is peculiar in that it does not include the space for the
trailing '\0', forcing all users to use KSYM_NAME_LEN + 1 when allocating
buffer. This is nonsense and error-prone. Moreover, when the caller
forgets that it's very likely to subtly bite back by corrupting the stack
because the last position of the buffer is always cleared to zero.
This patch increments KSYM_NAME_LEN by one and updates code accordingly.
* off-by-one bug in asm-powerpc/kprobes.h::kprobe_lookup_name() macro
is fixed.
* Where MODULE_NAME_LEN and KSYM_NAME_LEN were used together,
MODULE_NAME_LEN was treated as if it didn't include space for the
trailing '\0'. Fix it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Paulo Marques <pmarques@grupopie.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The last two slots of MAP 00b of ich6m was incorrectly marked as
reserved. This is left over from converting the entry to allow 00b.
This causes no real problem. It only makes the driver print annoying
warning message. Fix it.
[patch also proferred by Pierre Tardy at the end of 2006 -jg]
Signed-off-by: Tejun Heo <htejun@gmail.com>
--
drivers/ata/ata_piix.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This patch makes dentries and inodes for sysfs directories
reclaimable.
* sysfs_notify() is modified to walk sysfs_dirent tree instead of
dentry tree.
* sysfs_update_file() and sysfs_chmod_file() use sysfs_get_dentry() to
grab the victim dentry.
* sysfs_rename_dir() and sysfs_move_dir() grab all dentries using
sysfs_get_dentry() on startup.
* Dentries for all shadowed directories are pinned in memory to serve
as lookup start point.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some sysfs operations require dentry and inode. sysfs_get_dentry()
looks up and gets dentry for the specified sysfs_dirent. It finds the
first ancestor with dentry attached and starts looking up dentries
from there.
Looking up from the nearest ancestor is necessary to support shadowed
directories because we can't reliably lookup dentry for one of the
shadows. Dentries for each shadow will be pinned in memory such that
they can serve as the starting point for dentry lookup.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
After add/remove path restructuring, the only user of
sysfs_drop_dentry() is sysfs_addrm_finish(). Move sysfs_drop_dentry()
to dir.c and make it static.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The original add/remove code had the following problems.
* parent's timestamps are updated on dentry instantiation. this is
incorrect with reclaimable files.
* updating parent's timestamps isn't synchronized.
* parent nlink update assumes the inode is accessible which won't be
true once directory dentries are made reclaimable.
This patch restructures add/remove paths to resolve the above
problems. Add/removal are done in the following steps.
1. sysfs_addrm_start() : acquire locks including sysfs_mutex and other
resources.
2-a. sysfs_add_one() : add new sd. linking the new sd into the
children list is caller's responsibility.
2-b. sysfs_remove_one() : remove a sd. unlinking the sd from the
children list is caller's responsibility.
3. sysfs_addrm_finish() : release all resources and clean up.
Steps 2-a and/or 2-b can be repeated multiple times.
Parent's inode is looked up during sysfs_addrm_start(). If available
(always at the moment), it's pinned and nlink is updated as sd's are
added and removed. Timestamps are updated during finish if any sd has
been added or removed. If parent's inode is not available during
start, sysfs_mutex ensures that parent inode is not created till
add/remove is complete.
All the complexity is contained inside the helper functions.
Especially, dentry/inode handling is properly hidden from the rest of
sysfs which now mostly operate on sysfs_dirents. As an added bonus,
codes which use these helpers to add and remove sysfs_dirents are now
more structured and simpler.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As kobj sysfs dentries and inodes are gonna be made reclaimable,
i_mutex can't be used to protect sysfs_dirent tree. Use sysfs_mutex
globally instead. As the whole tree is protected with sysfs_mutex,
there is no reason to keep sysfs_rename_sem. Drop it.
While at it, add docbook comments to functions which require
sysfs_mutex locking.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Replace sysfs_lock and kobj_sysfs_assoc_lock with sysfs_assoc_lock.
sysfs_lock was originally to be used to protect sysfs_dirent tree but
mutex seems better choice, so there is no reason to keep sysfs_lock
separate. Merge the two spinlocks into one.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As kobj sysfs dentries and inodes are gonna be made reclaimable,
dentry can't be used as naming token for sysfs file/directory, replace
kobj->dentry with kobj->sd. The only external interface change is
shadow directory handling. All other changes are contained in kobj
and sysfs.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Implement sysfs_find_dirent() and sysfs_get_dirent().
sysfs_dirent_exist() is replaced by sysfs_find_dirent(). These will
be used to make directory entries reclamiable.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Implement SYSFS_FLAG_REMOVED flag which currently is used only to
improve sanity check in sysfs_deactivate(). The flag will be used to
make directory entries reclamiable.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Rename sysfs_dirent->s_type to s_flags, pack type into lower eight
bits and reserve the rest for flags. sysfs_type() can used to access
the type. All existing sd->s_type accesses are converted to use
sysfs_type(). While at it, type test is changed to equality test
instead of bit-and test where appropriate.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs_drop_dentry() used to go through sd->s_dentry and
sd->s_parent->s_dentry to access the inodes. This is incorrect
because inode can be cached without dentry.
This patch makes sysfs_drop_dentry() access inodes using ilookup() on
sd->s_ino. This is both correct and simpler.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sysfs_dirent use singly linked list for its tree structure.
sysfs_link_sibling() and sysfs_unlink_sibling() functions are added to
handle simpler cases. It adds some complexity and cpu cycle overhead
but reduced memory footprint is worthwhile on big machines.
This change reduces the sizeof sysfs_dirent from 104 to 88 on 64bit
and from 60 to 52 on 32bit.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sysfs_dirent->s_active an atomic_t instead of rwsem. This
reduces the size of sysfs_dirent from 136 to 104 on 64bit and from 76
to 60 on 32bit with lock debugging turned off. With lock debugging
turned on the reduction is much larger.
s_active starts at zero and each active reference increments s_active.
Putting a reference decrements s_active. Deactivation subtracts
SD_DEACTIVATED_BIAS which is currently INT_MIN and assumed to be small
enough to make s_active negative. If s_active is negative,
sysfs_get() no longer grants new references. Deactivation succeeds
immediately if there is no active user; otherwise, it waits using a
completion for the last put.
Due to the removal of lockdep tricks, this change makes things less
trickier in release_sysfs_dirent(). As all the complexity is
contained in three s_active functions, I think it's more readable this
way.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
These functions are about to receive more complexity and doesn't
really need to be inlined in the first place. Move them from
fs/sysfs/sysfs.h to fs/sysfs/dir.c.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The root sysfs_dirent didn't point to the root dentry fix it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
After dentry is reclaimed, sysfs always used to allocate new dentry
and inode if the file is accessed again. This causes problem with
operations which only pin the inode. For example, if inotify watch is
added to a sysfs file and the dentry for the file is reclaimed, the
next update event creates new dentry and new inode making the inotify
watch miss all the events from there on.
This patch fixes it by using iget_locked() instead of new_inode().
sysfs_new_inode() is renamed to sysfs_get_inode() and inode is
initialized iff the inode is newly allocated. sysfs_instantiate() is
responsible for unlocking new inodes.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Reorganize/clean up sysfs_new_inode() and sysfs_create().
* sysfs_init_inode() is separated out from sysfs_new_inode() and is
responsible for basic initialization.
* sysfs_instantiate() replaces the last step of sysfs_create() and is
responsible for dentry instantitaion.
* type-specific initialization is moved out to the callers.
* mode is specified only once when creating a sysfs_dirent.
* spurious list_del_init(&sd->s_sibling) dropped from create_dir()
This change is to
* prepare for inode allocation fix.
* separate alloc and init code for synchronization update.
* make dentry/inode initialization more flexible for later changes.
This patch doesn't introduce visible behavior change.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs_alloc_ino() isn't used out side of fs/sysfs/dir.c. Make it
static.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
devt_attr and uevent_attr are either allocated dynamically with or
embedded in device and class_device as they needed their owner field
set to the module implementing the driver. Now that sysfs implements
immediate disconnect and owner field removed from struct attribute,
there is no reason to do this. Remove these attributes from
[class_]device and use static attribute structures instead.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs is now completely out of driver/module lifetime game. After
deletion, a sysfs node doesn't access anything outside sysfs proper,
so there's no reason to hold onto the attribute owners. Note that
often the wrong modules were accounted for as owners leading to
accessing removed modules.
This patch kills now unnecessary attribute->owner. Note that with
this change, userland holding a sysfs node does not prevent the
backing module from being unloaded.
For more info regarding lifetime rule cleanup, please read the
following message.
http://article.gmane.org/gmane.linux.kernel/510293
(tweaked by Greg to not delete the field just yet, to make it easier to
merge things properly.)
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch reimplements sysfs_drop_dentry() such that remove_dir() can
use it to drop dentry instead of using a separate mechanism. With
this change, making directories reclaimable is much easier.
This patch used to contain fixes for two race conditions around
sd->s_dentry but that part has been separated out and included into
mainline early as commit 6aa054aadf and
dd14cbc994.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Consolidate sd <-> dentry association into sysfs_attach_dentry() and
call it after dentry and inode are properly set up. This is in
preparation of sysfs_drop_dentry() updates.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that sysfs_dirent can be disconnected from kobject on deletion,
there is no need to orphan each attribute files. All [bin_]attribute
nodes are automatically orphaned when the parent node is deleted.
Kill attribute file orphaning.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs: implement sysfs_dirent active reference and immediate disconnect
Opening a sysfs node references its associated kobject, so userland
can arbitrarily prolong lifetime of a kobject which complicates
lifetime rules in drivers. This patch implements active reference and
makes the association between kobject and sysfs immediately breakable.
Now each sysfs_dirent has two reference counts - s_count and s_active.
s_count is a regular reference count which guarantees that the
containing sysfs_dirent is accessible. As long as s_count reference
is held, all sysfs internal fields in sysfs_dirent are accessible
including s_parent and s_name.
The newly added s_active is active reference count. This is acquired
by invoking sysfs_get_active() and it's the caller's responsibility to
ensure sysfs_dirent itself is accessible (should be holding s_count
one way or the other). Dereferencing sysfs_dirent to access objects
out of sysfs proper requires active reference. This includes access
to the associated kobjects, attributes and ops.
The active references can be drained and denied by calling
sysfs_deactivate(). All active sysfs_dirents must be deactivated
after deletion but before the default reference is dropped. This
enables immediate disconnect of sysfs nodes. Once a sysfs_dirent is
deleted, it won't access any entity external to sysfs proper.
Because attr/bin_attr ops access both the node itself and its parent
for kobject, they need to hold active references to both.
sysfs_get/put_active_two() helpers are provided to help grabbing both
references. Parent's is acquired first and released last.
Unlike other operations, mmapped area lingers on after mmap() is
finished and the module implement implementing it and kobj need to
stay referenced till all the mapped pages are gone. This is
accomplished by holding one set of active references to the bin_attr
and its parent if there have been any mmap during lifetime of an
openfile. The references are dropped when the openfile is released.
This change makes sysfs lifetime rules independent from both kobject's
and module's. It not only fixes several race conditions caused by
sysfs not holding onto the proper module when referencing kobject, but
also helps fixing and simplifying lifetime management in driver model
and drivers by taking sysfs out of the equation.
Please read the following message for more info.
http://article.gmane.org/gmane.linux.kernel/510293
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Implement bin_buffer which contains a mutex and pointer to PAGE_SIZE
buffer to properly synchronize accesses to per-openfile buffer and
prepare for immediate-kobj-disconnect.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs symlink is implemented by referencing dentry and kobject from
sysfs_dirent - symlink entry references kobject, dentry is used to
walk the tree. This complicates object lifetimes rules and is
dangerous - for example, there is no way to tell to which module the
target of a symlink belongs and referencing that kobject can make it
linger after the module is gone.
This patch reimplements symlink using only sysfs_dirent tree. sd for
a symlink points and holds reference to the target sysfs_dirent and
all walking is done using sysfs_dirent tree. Simpler and safer.
Please read the following message for more info.
http://article.gmane.org/gmane.linux.kernel/510293
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kobj->dentry can go away anytime unless the user controls when the
associated sysfs node is deleted. This patch implements
kobj_sysfs_assoc_lock which protects kobj->dentry. This will be used
to maintain kobj based API when converting sysfs to use sysfs_dirent
tree instead of dentry/kobject.
Note that this lock belongs to kobject/driver-model not sysfs. Once
sysfs is converted to not use kobject in its interface, this can be
removed from sysfs.
This is in preparation of object reference simplification.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sd->s_element a union of sysfs_elem_{dir|symlink|attr|bin_attr}
and rename it to s_elem. This is to achieve...
* some level of type checking : changing symlink to point to
sysfs_dirent instead of kobject is much safer and less painful now.
* easier / standardized dereferencing
* allow sysfs_elem_* to contain more than one entry
Where possible, pointer is obtained by directly deferencing from sd
instead of going through other entities. This reduces dependencies to
dentry, inode and kobject. to_attr() and to_bin_attr() are unused now
and removed.
This is in preparation of object reference simplification.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add s_name to sysfs_dirent. This is to further reduce dependency to
the associated dentry. Name is copied for directories and symlinks
but not for attributes.
Where possible, name dereferences are converted to use sd->s_name.
sysfs_symlink->link_name and sysfs_get_name() are unused now and
removed.
This change allows symlink to be implemented using sysfs_dirent tree
proper, which is the last remaining dentry-dependent sysfs walk.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add sysfs_dirent->s_parent. With this patch, each sd points to and
holds a reference to its parent. This allows walking sysfs tree
without referencing sd->s_dentry which can go away anytime if the user
doesn't control when it's deleted.
sd->s_parent is initialized and parent is referenced in
sysfs_attach_dirent(). Reference to parent is released when the sd is
released, so as long as reference to a sd is held, s_parent can be
followed.
dentry walk in sysfs_readdir() is convereted to s_parent walk.
This will be used to reimplement symlink such that it uses only
sysfs_dirent tree.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Currently there are four functions to create sysfs_dirent -
__sysfs_new_dirent(), sysfs_new_dirent(), __sysfs_make_dirent() and
sysfs_make_dirent(). Other than sysfs_make_dirent(), no function has
two users if calls to implement other functions are excluded.
This patch consolidates sysfs_dirent creation functions into the
following two.
* sysfs_new_dirent() : allocate and initialize
* sysfs_attach_dirent() : attach to sysfs_dirent hierarchy and/or
associate with dentry
This simplifies interface and gives callers more flexibility. This is
in preparation of object reference simplification.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Error handling in sysfs_rename_dir() was broken.
* When lookup_one_len() fails, 0 is returned.
* If parent inode check fails, returns with inode mutex and rename
rwsem held.
This patch fixes the above bugs and flattens error handling such that
it's more readable and easier to modify.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Flatten cleanup paths in sysfs_add_link() and create_dir() to improve
readability and ease further changes to these functions. This is in
preparation of object reference simplification.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Error handling in fs/sysfs/bin.c:write() was wrong because size_t
count is used to receive return value from flush_write() which is
negative on failure.
This patch updates write() such that int variable is used instead.
read() is updated the same way for consistency.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs used simple incrementing allocator which is not guaranteed to be
unique. This patch makes sysfs use ida to give each sd a unique and
packed inode number.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is no reason this function should be inlined and soon to follow
sysfs object reference simplification will make it heavier. Move it
to dir.c.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Implement idr based id allocator. ida is used the same way idr is
used but lacks id -> ptr translation and thus consumes much less
memory. struct ida_bitmap is attached as leaf nodes to idr tree which
is managed by the idr code. Each ida_bitmap is 128bytes long and
contains slightly less than a thousand slots.
ida is more aggressive with releasing extra resources acquired using
ida_pre_get(). After every successful id allocation, ida frees one
reserved idr_layer if possible. Reserved ida_bitmap is not freed
automatically but only one ida_bitmap is reserved and it's almost
always used right away. Under most circumstances, ida won't hold on
to memory for too long which isn't actively used.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Separate out idr_mark_full() from sub_alloc() and make marking the
allocated slot full the responsibility of idr_get_new_above_int().
Allocation part of idr_get_new_above_int() is renamed to
idr_get_empty_slot(). New idr_get_new_above_int() allocates a slot
using the function, install the user pointer and marks it full using
idr_mark_full().
This change doesn't introduce any behavior change. This will be
used by ida.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In sub_alloc(), when bitmap search fails, it goes up one level to
continue search. This is done by updating the id cursor and searching
the upper level again. If the cursor was at the end of the upper
level, we need to go further than that.
This wasn't implemented and when that happens the part of the cursor
which indexes into the upper level wraps and sub_alloc() ends up
searching the wrong bitmap. It allocates id which doesn't match the
actual slot.
This patch fixes this by restarting from the top if the search needs
to go higher than one level.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add Port Multiplier related ATA constants and macros. Some of these
will be used by ata_link implementation.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Separate out ata_eh_handle_dev_fail() from ata_eh_recover(). This is
in preparation of ata_link and PMP support.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Horkage handling had the following problems.
* dev->horkage was positioned after ATA_DEVICE_CLEAR_OFFSET, so it was
cleared before the device is configured. This broke
HORKAGE_DIAGNOSTIC.
* Some used dev->horkage while others called ata_device_blacklisted()
directly. This was at best confusing.
This patch moves dev->horkage right after dev->flags and set the field
according to the blacklist during device configuration. All users
test against dev->horkage. ata_device_blacklisted() now has only one
user, make it static. While at it, rename it to ata_dev_blacklisted()
for consistency.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
With PCI resource fix up for legacy hosts. We can use the same code
path to allocate IO resources and initialize host for both legacy and
native SFF hosts. Only IRQ requesting needs to be different.
Rename ata_pci_*_native_host() to ata_pci_*_sff_host(), kill all
legacy specific functions and use the renamed functions instead. This
simplifies code a lot.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Barrier bios are completed twice - once after the barrier write itself
is done and again after the whole sequence is complete.
flush_dry_bio_endio() is for the first completion. It doesn't really
complete the bio. It rewinds bvec and resets bio so that it can be
completed again when the whole barrier sequence is complete.
The bvec rewinding code has the following problems.
1. The rewinding code is wrong because filesystems may pass bvec with
non zero bv_offset.
2. The block layer doesn't guarantee anything about the state of
bvec array on request completion. bv_offset and len are updated
iff __end_that_request_first() completes the bvec partially.
Because of #2, #1 doesn't really matter (nobody cares whether bvec is
re-wound correctly or not) but then again by not doing unwinding at
all, we'll always give back the same bvec to the caller as full bvec
completion doesn't alter bvecs and the final completion is always full
completion.
Drop unnecessary rewinding code.
This is spotted by Neil Brown.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Fix various bugs in pio/mwdma mode programming.
* Control bits in the timing register wasn't cleared properly while
programming PIO mode.
* MWDMA mode programming cleared the wrong part of control bits.
* MWDMA mode programming cleared udma_mask even when the controller
doesn't support UDMA.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Art Haas <ahaas@airmail.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
ap->cbl == ATA_CBL_SATA indicates SATA cable while ap->flags &
ATA_FLAG_SATA indicates SATA host port. Till now they always gave the
same result but SATA/PATA bridge handling will change that. Switch to
ATA_FLAG_SATA test if we're testing for host port type.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Implement _GTM/_STM support. acpi_gtm is added to ata_port which
stores _GTM parameters over suspend/resume cycle. A new hook
ata_acpi_on_suspend() is responsible for storing _GTM parameters
during suspend. _STM is executed in ata_acpi_on_resume(). With this
change, invoking _GTF is safe on IDE hierarchy and acpi_sata check
before _GTF is removed.
ata_acpi_gtm() and ata_acpi_stm() implementation is taken from Alan
Cox's pata_acpi implementation. ata_acpi_gtm() is fixed such that the
result parameter is not shifted by sizeof(union acpi_object).
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This patch reimplements ACPI invocation such that, instead of
exporting ACPI details to the rest of libata, ACPI event handlers -
ata_acpi_on_resume() and ata_acpi_on_devcfg() - are used. These two
functions are responsible for determining whether specific ACPI method
is used and when.
On resume, _GTF is scheduled by setting ATA_DFLAG_ACPI_PENDING device
flag. This is done this way to avoid performing the action on wrong
device device (device swapping while suspended).
On every ata_dev_configure(), ata_acpi_on_devcfg() is called, which
performs _SDD and _GTF. _GTF is performed only after resuming and, if
SATA, hardreset as the ACPI spec specifies. As _GTF may contain
arbitrary commands, IDENTIFY page is re-read after _GTF taskfiles are
executed.
If one of ACPI methods fails, ata_acpi_on_devcfg() retries on the
first failure. If it fails again on the second try, ACPI is disabled
on the device. Note that successful configuration clears ACPI failed
status.
With all feature checks moved to the above two functions,
do_drive_set_taskfiles() is trivial and thus collapsed into
ata_acpi_exec_tfs(), which is now static and converted to return the
number of executed taskfiles to be used by ata_acpi_on_resume(). As
failures are handled properly, ata_acpi_push_id() now returns -errno
on errors instead of unconditional zero.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
* Add missing LOCKING: and RETURNS: to function comment.
* Don't conditionalize warning messages with ata_msg_probe(). Print
directly with KERN_WARNING.
* Drop duplicate debug messages.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This patch cleans up ata_acpi_exec_tfs() and its friends.
* Rename taskfile_array to ata_acpi_gtf and make it __packed as it's
used as argument to ACPI method, and use pointer to ata_acpi_gtf and
number of taskfiles to represent _GTF taskfiles instead of a pointer
casted into unsigned long and byte count. This makes argument
re-checking in do_drive_set_taskfiles() unnecessary.
* Pointer in void * not in unsigned long.
* Clean up do_drive_get_GTF() error handling and make
do_drive_get_GTF() return number of taskfiles on success, 0 if _GTF
doesn't exist or doesn't contain valid ata. -errno on other errors.
* Remove superflous check for acpi->buffer.pointer.
* Update taskfile_load_raw() such that printed messages look similar
to the messages printed by ata_eh_report().
* s/do_drive_get_GTF/ata_dev_get_GTF/
s/do_drive_set_taskfiles/ata_dev_set_taskfiles/
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
* Add acpi_handle to ata_host and ata_port. Rename
ata_device->obj_handle to ->acpi_handle and move it above such that
it doesn't get cleared on reconfiguration.
* Replace ACPI node association which ata_acpi_associate() which is
called once during host initialization. Unlike the previous
implementation, ata_acpi_associate() uses ATA_FLAG_ACPI_SATA to
choose between IDE or SATA ACPI hierarchy and uses simple child look
up instead of recursive walk to match the nodes. This is way safer
and simpler. Please read the following message for more info.
http://article.gmane.org/gmane.linux.ide/17554
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
host->irq and host->irq2 should be set before ata_host_register() for
IRQ reporting to work. Move up host->irq assignment in
ata_host_activate() and add it to ata_pci_init_one() native path and
pata_cs5520.
The port info printing in ata_host_register() doesn't fit all the
different controllers. It should probably be moved out to LLDs with
some helpers in the future.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
sata_inic162x can't do LBA48 properly yet and is likely to corrupt
data on drives larger than LBA28 limit. Disable LBA48 devices during
device configuration.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
ATA_HORKAGE_DMA_RW_ONLY for TORiSAN is verified to be subset of using
DMA for ATAPI commands which aren't aligned to 16 bytes. As libata
now doesn't use DMA for unaligned ATAPI commands, the horkage is
redundant. Kill it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
The IDE driver used DMA for ATAPI commands if READ/WRITE command is
multiple of sector size or sg command is multiple of 16 bytes. For
libata, READ/WRITE sector alignment is guaranteed by the high level
driver (sr), so we only have to worry about the 16 byte alignment.
This patch makes ata_check_atapi_dma() always request PIO for all data
transfer commands which are not multiple of 16 bytes.
The following reports are related to this problem.
http://bugzilla.kernel.org/show_bug.cgi?id=8605 (confirmed)
http://thread.gmane.org/gmane.linux.kernel/476620 (confirmed)
https://bugzilla.novell.com/show_bug.cgi?id=229260 (probably)
Albert first pointed out the difference between IDE and libata. Kudos
to him.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
In atapi_xlat(), prepare qc better before calling
ata_check_atapi_dma() such that ata_check_atapi_dma() can use info
from qc. While at it, reformat weird looking if/else block in the
function.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
When EH gives up after repeated exceptions, it doesn't't clear the
PENDING bit on exit which leaves PENDING bit set without EH actually
scheduled. This makes ata_port_wait_eh() to wait forever makes rmmod
hang on such port. Fix it by clearing the flag.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
There's no reason to print out hpa related messages when HPA is not
active. Kill the unconditional message and add a warning message
which is printed if HPA size is smaller than the current size.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
prereset() is now allowed to set flag for unsupported reset method.
EH layer is responsible for selecting the fallback. Remove non-sense
warning message.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
The infamous abnormal status message triggers on not so abnormal cases
including empty port and even when it's being triggered on actual
errors the info it provides is redundant and out of context - higher
level functions will print the info in better safe later anyway.
Also, by being triggered all the time, it leads people to think that
the abnormality is somehow related to all ATA and system problems
they're experiencing and gives owners of healthy systems unfounded
doubts about the integrity of the universe. Make it a DPRINTK and
save the universe.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
If PORTS_IMPL register is zero, ahci initialize it to full mask
corresponding to nr_ports in the CAP register. hpriv->cap, which is
initialized at the end of the function, is incorrectly used as value
of CAP causing ahci to always override PORTS_IMPL to 0x1 if it's zero.
Fix it.
This fixes a bug where early ich6 ahci can only access the first port.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
More for the NCQ blacklist. One hitachi and one raptor. Other
members of these families of drives are already on the list, so no
surprises.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
SCSI marks internal commands with REQ_PREEMPT and push it at the front
of the request queue using blk_execute_rq(). When entering suspended
or frozen state, SCSI devices are quiesced using
scsi_device_quiesce(). In quiesced state, only REQ_PREEMPT requests
are processed. This is how SCSI blocks other requests out while
suspending and resuming. As all internal commands are pushed at the
front of the queue, this usually works.
Unfortunately, this interacts badly with ordered requeueing. To
preserve request order on requeueing (due to busy device, active EH or
other failures), requests are sorted according to ordered sequence on
requeue if IO barrier is in progress.
The following sequence deadlocks.
1. IO barrier sequence issues.
2. Suspend requested. Queue is quiesced with part or all of IO
barrier sequence at the front.
3. During suspending or resuming, SCSI issues internal command which
gets deferred and requeued for some reason. As the command is
issued after the IO barrier in #1, ordered requeueing code puts the
request after IO barrier sequence.
4. The device is ready to process requests again but still is in
quiesced state and the first request of the queue isn't
REQ_PREEMPT, so command processing is deadlocked -
suspending/resuming waits for the issued request to complete while
the request can't be processed till device is put back into
running state by resuming.
This can be fixed by always putting !fs requests at the front when
requeueing.
The following thread reports this deadlock.
http://thread.gmane.org/gmane.linux.kernel/537473
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: David Greaves <david@dgreaves.com>
Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allowing attribute and symlink dentries to be reclaimed means
sd->s_dentry can change dynamically. However, updates to the field
are unsynchronized leading to race conditions. This patch adds
sysfs_lock and use it to synchronize updates to sd->s_dentry.
Due to the locking around ->d_iput, the check in sysfs_drop_dentry()
is complex. sysfs_lock only protect sd->s_dentry pointer itself. The
validity of the dentry is protected by dcache_lock, so whether dentry
is alive or not can only be tested while holding both locks.
This is minimal backport of sysfs_drop_dentry() rewrite in devel
branch.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The condition check doesn't make much sense as it basically always
succeeds. This causes NULL dereferencing on certain cases. It seems
that parentheses are put in the wrong place. Fix it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Tejun Heo