/*
 * Cache operations for Coda.
 * For Linux 2.1: (C) 1997 Carnegie Mellon University
 * For Linux 2.3: (C) 2000 Carnegie Mellon University
 *
 * Carnegie Mellon encourages users of this code to contribute improvements
 * to the Coda project http://www.coda.cs.cmu.edu/ <coda@cs.cmu.edu>.
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/uaccess.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/spinlock.h>

#include <linux/coda.h>
#include <linux/coda_psdev.h>
#include "coda_linux.h"
#include "coda_cache.h"

static atomic_t permission_epoch = ATOMIC_INIT(0);

/* replace or extend an acl cache hit */
void coda_cache_enter(struct inode *inode, int mask)
{
	struct coda_inode_info *cii = ITOC(inode);

	spin_lock(&cii->c_lock);
	cii->c_cached_epoch = atomic_read(&permission_epoch);
	if (!uid_eq(cii->c_uid, current_fsuid())) {
		cii->c_uid = current_fsuid();
                cii->c_cached_perm = mask;
        } else
                cii->c_cached_perm |= mask;
	spin_unlock(&cii->c_lock);
}

/* remove cached acl from an inode */
void coda_cache_clear_inode(struct inode *inode)
{
	struct coda_inode_info *cii = ITOC(inode);
	spin_lock(&cii->c_lock);
	cii->c_cached_epoch = atomic_read(&permission_epoch) - 1;
	spin_unlock(&cii->c_lock);
}

/* remove all acl caches */
void coda_cache_clear_all(struct super_block *sb)
{
	atomic_inc(&permission_epoch);
}


/* check if the mask has been matched against the acl already */
int coda_cache_check(struct inode *inode, int mask)
{
	struct coda_inode_info *cii = ITOC(inode);
	int hit;
	
	spin_lock(&cii->c_lock);
	hit = (mask & cii->c_cached_perm) == mask &&
	    uid_eq(cii->c_uid, current_fsuid()) &&
	    cii->c_cached_epoch == atomic_read(&permission_epoch);
	spin_unlock(&cii->c_lock);

	return hit;
}


/* Purging dentries and children */
/* The following routines drop dentries which are not
   in use and flag dentries which are in use to be 
   zapped later.

   The flags are detected by:
   - coda_dentry_revalidate (for lookups) if the flag is C_PURGE
   - coda_dentry_delete: to remove dentry from the cache when d_count
     falls to zero
   - an inode method coda_revalidate (for attributes) if the 
     flag is C_VATTR
*/

/* this won't do any harm: just flag all children */
static void coda_flag_children(struct dentry *parent, int flag)
{
	struct dentry *de;

	spin_lock(&parent->d_lock);
	list_for_each_entry(de, &parent->d_subdirs, d_child) {
		/* don't know what to do with negative dentries */
		if (d_inode(de) ) 
			coda_flag_inode(d_inode(de), flag);
	}
	spin_unlock(&parent->d_lock);
	return; 
}

void coda_flag_inode_children(struct inode *inode, int flag)
{
	struct dentry *alias_de;

	if ( !inode || !S_ISDIR(inode->i_mode)) 
		return; 

	alias_de = d_find_alias(inode);
	if (!alias_de)
		return;
	coda_flag_children(alias_de, flag);
	shrink_dcache_parent(alias_de);
	dput(alias_de);
}

</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/trace/events?id=2a4c32edd39b7de166e723b1991abcde4db3a701'>events</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='2a4c32edd39b7de166e723b1991abcde4db3a701'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2016-12-14 10:58:17 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2016-12-14 10:58:17 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/trace/events?id=2a4c32edd39b7de166e723b1991abcde4db3a701'>2a4c32edd39b7de166e723b1991abcde4db3a701</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/trace/events?id=2a4c32edd39b7de166e723b1991abcde4db3a701'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=2a4c32edd39b7de166e723b1991abcde4db3a701'>1eba8e303e19d0f8fa0874f4514f87ebac82ae5c</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/trace/events?id=2a4c32edd39b7de166e723b1991abcde4db3a701'>include/trace/events</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/trace/events?id=b9f98bd4034a3196ff068eb0fa376c5f41077480'>b9f98bd4034a3196ff068eb0fa376c5f41077480</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/trace/events?id=2a4c32edd39b7de166e723b1991abcde4db3a701&amp;id2=b9f98bd4034a3196ff068eb0fa376c5f41077480'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/trace/events?id=20737738d397dfadbca1ea50dcc00d7259f500cf'>20737738d397dfadbca1ea50dcc00d7259f500cf</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/trace/events?id=2a4c32edd39b7de166e723b1991abcde4db3a701&amp;id2=20737738d397dfadbca1ea50dcc00d7259f500cf'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md</div><div class='commit-msg'>Pull MD updates from Shaohua Li:

 - a raid5 writeback cache feature.

   The goal is to aggregate writes to make full stripe write and reduce
   read-modify-write. It's helpful for workload which does sequential
   write and follows fsync for example. This feature is experimental and
   off by default right now.

 - FAILFAST support.

   This fails IOs to broken raid disks quickly, so can improve latency.
   It's mainly for DASD storage, but some patches help normal raid array
   too.

 - support bad block for raid array with external metadata

 - AVX2 instruction support for raid6 parity calculation

 - normalize MD info output

 - add missing blktrace

 - other bug fixes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md: (66 commits)
  md: separate flags for superblock changes
  md: MD_RECOVERY_NEEDED is set for mddev-&gt;recovery
  md: takeover should clear unrelated bits
  md/r5cache: after recovery, increase journal seq by 10000
  md/raid5-cache: fix crc in rewrite_data_only_stripes()
  md/raid5-cache: no recovery is required when create super-block
  md: fix refcount problem on mddev when stopping array.
  md/r5cache: do r5c_update_log_state after log recovery
  md/raid5-cache: adjust the write position of the empty block if no data blocks
  md/r5cache: run_no_space_stripes() when R5C_LOG_CRITICAL == 0
  md/raid5: limit request size according to implementation limits
  md/raid5-cache: do not need to set STRIPE_PREREAD_ACTIVE repeatedly
  md/raid5-cache: remove the unnecessary next_cp_seq field from the r5l_log
  md/raid5-cache: release the stripe_head at the appropriate location
  md/raid5-cache: use ring add to prevent overflow
  md/raid5-cache: remove unnecessary function parameters
  raid5-cache: don't set STRIPE_R5C_PARTIAL_STRIPE flag while load stripe into cache
  raid5-cache: add another check conditon before replaying one stripe
  md/r5cache: enable IRQs on error path
  md/r5cache: handle alloc_page failure
  ...
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=2a4c32edd39b7de166e723b1991abcde4db3a701'>Diffstat</a> (limited to 'include/trace/events')</div><table summary='diffstat' class='diffstat'>