cregit-Linux how code gets into the kernel

Release 4.10 fs/ocfs2/dcache.c

Directory: fs/ocfs2
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 * dcache.c
 * dentry cache handling code
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * General Public License for more details.
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.

#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/namei.h>

#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "dcache.h"
#include "dlmglue.h"
#include "file.h"
#include "inode.h"
#include "ocfs2_trace.h"

void ocfs2_dentry_attach_gen(struct dentry *dentry) { unsigned long gen = OCFS2_I(d_inode(dentry->d_parent))->ip_dir_lock_gen; BUG_ON(d_inode(dentry)); dentry->d_fsdata = (void *)gen; }


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david howellsdavid howells613.64%150.00%

static int ocfs2_dentry_revalidate(struct dentry *dentry, unsigned int flags) { struct inode *inode; int ret = 0; /* if all else fails, just return false */ struct ocfs2_super *osb; if (flags & LOOKUP_RCU) return -ECHILD; inode = d_inode(dentry); osb = OCFS2_SB(dentry->d_sb); trace_ocfs2_dentry_revalidate(dentry, dentry->d_name.len, dentry->; /* For a negative dentry - * check the generation number of the parent and compare with the * one stored in the inode. */ if (inode == NULL) { unsigned long gen = (unsigned long) dentry->d_fsdata; unsigned long pgen; spin_lock(&dentry->d_lock); pgen = OCFS2_I(d_inode(dentry->d_parent))->ip_dir_lock_gen; spin_unlock(&dentry->d_lock); trace_ocfs2_dentry_revalidate_negative(dentry->d_name.len, dentry->, pgen, gen); if (gen != pgen) goto bail; goto valid; } BUG_ON(!osb); if (inode == osb->root_inode || is_bad_inode(inode)) goto bail; spin_lock(&OCFS2_I(inode)->ip_lock); /* did we or someone else delete this inode? */ if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_DELETED) { spin_unlock(&OCFS2_I(inode)->ip_lock); trace_ocfs2_dentry_revalidate_delete( (unsigned long long)OCFS2_I(inode)->ip_blkno); goto bail; } spin_unlock(&OCFS2_I(inode)->ip_lock); /* * We don't need a cluster lock to test this because once an * inode nlink hits zero, it never goes back. */ if (inode->i_nlink == 0) { trace_ocfs2_dentry_revalidate_orphaned( (unsigned long long)OCFS2_I(inode)->ip_blkno, S_ISDIR(inode->i_mode)); goto bail; } /* * If the last lookup failed to create dentry lock, let us * redo it. */ if (!dentry->d_fsdata) { trace_ocfs2_dentry_revalidate_nofsdata( (unsigned long long)OCFS2_I(inode)->ip_blkno); goto bail; } valid: ret = 1; bail: trace_ocfs2_dentry_revalidate_ret(ret); return ret; }


mark fashehmark fasheh20863.61%330.00%
goldwyn rodriguesgoldwyn rodrigues3911.93%110.00%
tao matao ma3310.09%220.00%
al viroal viro237.03%220.00%
nick pigginnick piggin185.50%110.00%
david howellsdavid howells61.83%110.00%

static int ocfs2_match_dentry(struct dentry *dentry, u64 parent_blkno, int skip_unhashed) { struct inode *parent; /* * ocfs2_lookup() does a d_splice_alias() _before_ attaching * to the lock data, so we skip those here, otherwise * ocfs2_dentry_attach_lock() will get its original dentry * back. */ if (!dentry->d_fsdata) return 0; if (!dentry->d_parent) return 0; if (skip_unhashed && d_unhashed(dentry)) return 0; parent = d_inode(dentry->d_parent); /* Negative parent dentry? */ if (!parent) return 0; /* Name is in a different directory. */ if (OCFS2_I(parent)->ip_blkno != parent_blkno) return 0; return 1; }


mark fashehmark fasheh8896.70%150.00%
david howellsdavid howells33.30%150.00%

/* * Walk the inode alias list, and find a dentry which has a given * parent. ocfs2_dentry_attach_lock() wants to find _any_ alias as it * is looking for a dentry_lock reference. The downconvert thread is * looking to unhash aliases, so we allow it to skip any that already * have that property. */
struct dentry *ocfs2_find_local_alias(struct inode *inode, u64 parent_blkno, int skip_unhashed) { struct dentry *dentry; spin_lock(&inode->i_lock); hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) { spin_lock(&dentry->d_lock); if (ocfs2_match_dentry(dentry, parent_blkno, skip_unhashed)) { trace_ocfs2_find_local_alias(dentry->d_name.len, dentry->; dget_dlock(dentry); spin_unlock(&dentry->d_lock); spin_unlock(&inode->i_lock); return dentry; } spin_unlock(&dentry->d_lock); } spin_unlock(&inode->i_lock); return NULL; }


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nick pigginnick piggin3529.17%444.44%
al viroal viro1613.33%333.33%
tao matao ma10.83%111.11%

DEFINE_SPINLOCK(dentry_attach_lock); /* * Attach this dentry to a cluster lock. * * Dentry locks cover all links in a given directory to a particular * inode. We do this so that ocfs2 can build a lock name which all * nodes in the cluster can agree on at all times. Shoving full names * in the cluster lock won't work due to size restrictions. Covering * links inside of a directory is a good compromise because it still * allows us to use the parent directory lock to synchronize * operations. * * Call this function with the parent dir semaphore and the parent dir * cluster lock held. * * The dir semaphore will protect us from having to worry about * concurrent processes on our node trying to attach a lock at the * same time. * * The dir cluster lock (held at either PR or EX mode) protects us * from unlink and rename on other nodes. * * A dput() can happen asynchronously due to pruning, so we cover * attaching and detaching the dentry lock with a * dentry_attach_lock. * * A node which has done lookup on a name retains a protected read * lock until final dput. If the user requests and unlink or rename, * the protected read is upgraded to an exclusive lock. Other nodes * who have seen the dentry will then be informed that they need to * downgrade their lock, which will involve d_delete on the * dentry. This happens in ocfs2_dentry_convert_worker(). */
int ocfs2_dentry_attach_lock(struct dentry *dentry, struct inode *inode, u64 parent_blkno) { int ret; struct dentry *alias; struct ocfs2_dentry_lock *dl = dentry->d_fsdata; trace_ocfs2_dentry_attach_lock(dentry->d_name.len, dentry->, (unsigned long long)parent_blkno, dl); /* * Negative dentry. We ignore these for now. * * XXX: Could we can improve ocfs2_dentry_revalidate() by * tracking these? */ if (!inode) return 0; if (d_really_is_negative(dentry) && dentry->d_fsdata) { /* Converting a negative dentry to positive Clear dentry->d_fsdata */ dentry->d_fsdata = dl = NULL; } if (dl) { mlog_bug_on_msg(dl->dl_parent_blkno != parent_blkno, " \"%pd\": old parent: %llu, new: %llu\n", dentry, (unsigned long long)parent_blkno, (unsigned long long)dl->dl_parent_blkno); return 0; } alias = ocfs2_find_local_alias(inode, parent_blkno, 0); if (alias) { /* * Great, an alias exists, which means we must have a * dentry lock already. We can just grab the lock off * the alias and add it to the list. * * We're depending here on the fact that this dentry * was found and exists in the dcache and so must have * a reference to the dentry_lock because we can't * race creates. Final dput() cannot happen on it * since we have it pinned, so our reference is safe. */ dl = alias->d_fsdata; mlog_bug_on_msg(!dl, "parent %llu, ino %llu\n", (unsigned long long)parent_blkno, (unsigned long long)OCFS2_I(inode)->ip_blkno); mlog_bug_on_msg(dl->dl_parent_blkno != parent_blkno, " \"%pd\": old parent: %llu, new: %llu\n", dentry, (unsigned long long)parent_blkno, (unsigned long long)dl->dl_parent_blkno); trace_ocfs2_dentry_attach_lock_found(dl->dl_lockres.l_name, (unsigned long long)parent_blkno, (unsigned long long)OCFS2_I(inode)->ip_blkno); goto out_attach; } /* * There are no other aliases */ dl = kmalloc(sizeof(*dl), GFP_NOFS); if (!dl) { ret = -ENOMEM; mlog_errno(ret); return ret; } dl->dl_count = 0; /* * Does this have to happen below, for all attaches, in case * the struct inode gets blown away by the downconvert thread? */ dl->dl_inode = igrab(inode); dl->dl_parent_blkno = parent_blkno; ocfs2_dentry_lock_res_init(dl, parent_blkno, inode); out_attach: spin_lock(&dentry_attach_lock); dentry->d_fsdata = dl; dl->dl_count++; spin_unlock(&dentry_attach_lock); /* * This actually gets us our PRMODE level lock. From now on, * we'll have a notification if one of these names is * destroyed on another node. */ ret = ocfs2_dentry_lock(dentry, 0); if (!ret) ocfs2_dentry_unlock(dentry, 0); else mlog_errno(ret); /* * In case of error, manually free the allocation and do the iput(). * We need to do this because error here means no d_instantiate(), * which means iput() will not be called during dput(dentry). */ if (ret < 0 && !alias) { ocfs2_lock_res_free(&dl->dl_lockres); BUG_ON(dl->dl_count != 1); spin_lock(&dentry_attach_lock); dentry->d_fsdata = NULL; spin_unlock(&dentry_attach_lock); kfree(dl); iput(inode); } dput(alias); return ret; }


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sunil mushransunil mushran5713.51%111.11%
tao matao ma214.98%111.11%
goldwyn rodriguesgoldwyn rodrigues194.50%111.11%
david howellsdavid howells30.71%111.11%
al viroal viro20.47%111.11%

/* * ocfs2_dentry_iput() and friends. * * At this point, our particular dentry is detached from the inodes * alias list, so there's no way that the locking code can find it. * * The interesting stuff happens when we determine that our lock needs * to go away because this is the last subdir alias in the * system. This function needs to handle a couple things: * * 1) Synchronizing lock shutdown with the downconvert threads. This * is already handled for us via the lockres release drop function * called in ocfs2_release_dentry_lock() * * 2) A race may occur when we're doing our lock shutdown and * another process wants to create a new dentry lock. Right now we * let them race, which means that for a very short while, this * node might have two locks on a lock resource. This should be a * problem though because one of them is in the process of being * thrown out. */
static void ocfs2_drop_dentry_lock(struct ocfs2_super *osb, struct ocfs2_dentry_lock *dl) { iput(dl->dl_inode); ocfs2_simple_drop_lockres(osb, &dl->dl_lockres); ocfs2_lock_res_free(&dl->dl_lockres); kfree(dl); }


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jan karajan kara48.70%240.00%
goldwyn rodriguesgoldwyn rodrigues36.52%120.00%

void ocfs2_dentry_lock_put(struct ocfs2_super *osb, struct ocfs2_dentry_lock *dl) { int unlock = 0; BUG_ON(dl->dl_count == 0); spin_lock(&dentry_attach_lock); dl->dl_count--; unlock = !dl->dl_count; spin_unlock(&dentry_attach_lock); if (unlock) ocfs2_drop_dentry_lock(osb, dl); }


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goldwyn rodriguesgoldwyn rodrigues23.12%150.00%

static void ocfs2_dentry_iput(struct dentry *dentry, struct inode *inode) { struct ocfs2_dentry_lock *dl = dentry->d_fsdata; if (!dl) { /* * No dentry lock is ok if we're disconnected or * unhashed. */ if (!(dentry->d_flags & DCACHE_DISCONNECTED) && !d_unhashed(dentry)) { unsigned long long ino = 0ULL; if (inode) ino = (unsigned long long)OCFS2_I(inode)->ip_blkno; mlog(ML_ERROR, "Dentry is missing cluster lock. " "inode: %llu, d_flags: 0x%x, d_name: %pd\n", ino, dentry->d_flags, dentry); } goto out; } mlog_bug_on_msg(dl->dl_count == 0, "dentry: %pd, count: %u\n", dentry, dl->dl_count); ocfs2_dentry_lock_put(OCFS2_SB(dentry->d_sb), dl); out: iput(inode); }


mark fashehmark fasheh13098.48%266.67%
al viroal viro21.52%133.33%

/* * d_move(), but keep the locks in sync. * * When we are done, "dentry" will have the parent dir and name of * "target", which will be thrown away. * * We manually update the lock of "dentry" if need be. * * "target" doesn't have it's dentry lock touched - we allow the later * dput() to handle this for us. * * This is called during ocfs2_rename(), while holding parent * directory locks. The dentries have already been deleted on other * nodes via ocfs2_remote_dentry_delete(). * * Normally, the VFS handles the d_move() for the file system, after * the ->rename() callback. OCFS2 wants to handle this internally, so * the new lock can be created atomically with respect to the cluster. */
void ocfs2_dentry_move(struct dentry *dentry, struct dentry *target, struct inode *old_dir, struct inode *new_dir) { int ret; struct ocfs2_super *osb = OCFS2_SB(old_dir->i_sb); struct inode *inode = d_inode(dentry); /* * Move within the same directory, so the actual lock info won't * change. * * XXX: Is there any advantage to dropping the lock here? */ if (old_dir == new_dir) goto out_move; ocfs2_dentry_lock_put(osb, dentry->d_fsdata); dentry->d_fsdata = NULL; ret = ocfs2_dentry_attach_lock(dentry, inode, OCFS2_I(new_dir)->ip_blkno); if (ret) mlog_errno(ret); out_move: d_move(dentry, target); }


mark fashehmark fasheh10697.25%266.67%
david howellsdavid howells32.75%133.33%

const struct dentry_operations ocfs2_dentry_ops = { .d_revalidate = ocfs2_dentry_revalidate, .d_iput = ocfs2_dentry_iput, };

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sunil mushransunil mushran574.02%13.33%
tao matao ma563.95%26.67%
nick pigginnick piggin533.74%516.67%
al viroal viro443.10%723.33%
david howellsdavid howells211.48%13.33%
jan karajan kara60.42%26.67%
robert p. j. dayrobert p. j. day10.07%13.33%
Directory: fs/ocfs2
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