/*
* (C) 2001 Clemson University and The University of Chicago
*
* See COPYING in top-level directory.
*/
/*
* Implementation of dentry (directory cache) functions.
*/
#include "protocol.h"
#include "orangefs-kernel.h"
/* Returns 1 if dentry can still be trusted, else 0. */
static int orangefs_revalidate_lookup(struct dentry *dentry)
{
struct dentry *parent_dentry = dget_parent(dentry);
struct inode *parent_inode = parent_dentry->d_inode;
struct orangefs_inode_s *parent = ORANGEFS_I(parent_inode);
struct inode *inode = dentry->d_inode;
struct orangefs_kernel_op_s *new_op;
int ret = 0;
int err = 0;
gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: attempting lookup.\n", __func__);
new_op = op_alloc(ORANGEFS_VFS_OP_LOOKUP);
if (!new_op)
goto out_put_parent;
new_op->upcall.req.lookup.sym_follow = ORANGEFS_LOOKUP_LINK_NO_FOLLOW;
new_op->upcall.req.lookup.parent_refn = parent->refn;
strncpy(new_op->upcall.req.lookup.d_name,
dentry->d_name.name,
ORANGEFS_NAME_MAX);
gossip_debug(GOSSIP_DCACHE_DEBUG,
"%s:%s:%d interrupt flag [%d]\n",
__FILE__,
__func__,
__LINE__,
get_interruptible_flag(parent_inode));
err = service_operation(new_op, "orangefs_lookup",
get_interruptible_flag(parent_inode));
/* Positive dentry: reject if error or not the same inode. */
if (inode) {
if (err) {
gossip_debug(GOSSIP_DCACHE_DEBUG,
"%s:%s:%d lookup failure.\n",
__FILE__, __func__, __LINE__);
goto out_drop;
}
if (!match_handle(new_op->downcall.resp.lookup.refn.khandle,
inode)) {
gossip_debug(GOSSIP_DCACHE_DEBUG,
"%s:%s:%d no match.\n",
__FILE__, __func__, __LINE__);
goto out_drop;
}
/* Negative dentry: reject if success or error other than ENOENT. */
} else {
gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry.\n",
__func__);
if (!err || err != -ENOENT) {
if (new_op->downcall.status != 0)
gossip_debug(GOSSIP_DCACHE_DEBUG,
"%s:%s:%d lookup failure.\n",
__FILE__, __func__, __LINE__);
goto out_drop;
}
}
orangefs_set_timeout(dentry);
ret = 1;
out_release_op:
op_release(new_op);
out_put_parent:
dput(parent_dentry);
return ret;
out_drop:
gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d revalidate failed\n",
__FILE__, __func__, __LINE__);
goto out_release_op;
}
/*
* Verify that dentry is valid.
*
* Should return 1 if dentry can still be trusted, else 0.
*/
static int orangefs_d_revalidate(struct dentry *dentry, unsigned int flags)
{
int ret;
unsigned long time = (unsigned long) dentry->d_fsdata;
if (time_before(jiffies, time))
return 1;
if (flags & LOOKUP_RCU)
return -ECHILD;
gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: called on dentry %p.\n",
__func__, dentry);
/* skip root handle lookups. */
if (dentry->d_inode && is_root_handle(dentry->d_inode))
return 1;
/*
* If this passes, the positive dentry still exists or the negative
* dentry still does not exist.
*/
if (!orangefs_revalidate_lookup(dentry))
return 0;
/* We do not need to continue with negative dentries. */
if (!dentry->d_inode)
goto out;
/* Now we must perform a getattr to validate the inode contents. */
ret = orangefs_inode_check_changed(dentry->d_inode);
if (ret < 0) {
gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d getattr failure.\n",
__FILE__, __func__, __LINE__);
return 0;
}
if (ret == 0)
return 0;
out:
gossip_debug(GOSSIP_DCACHE_DEBUG,
"%s: negative dentry or positive dentry and inode valid.\n",
__func__);
return 1;
}
const struct dentry_operations orangefs_dentry_operations = {
.d_revalidate = orangefs_d_revalidate,
};
='4'>4
The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the
following double-lock bug:
Double lock:
1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236;
2. call to function `pl330_release_channel' immediately after;
3. call to function `dma_pl330_rqcb' in line 1753;
4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505.
I have fixed it as suggested by Marek Szyprowski.
First, I have replaced `pch->lock' with `pl330->lock' in functions
`pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids
the double-lock by acquiring a different lock than `dma_pl330_rqcb'.
NOTE that, as a result, `pl330_free_chan_resources' executes
`list_splice_tail_init' on `pch->work_list' under lock `pl330->lock',
whereas in the rest of the code `pch->work_list' is protected by
`pch->lock'. I don't know if this may cause race conditions. Similarly
`pch->cyclic' is written by `pl330_alloc_chan_resources' under
`pl330->lock' but read by `pl330_tx_submit' under `pch->lock'.
Second, I have removed locking from `pl330_request_channel' and
`pl330_release_channel' functions. Function `pl330_request_channel' is
only called from `pl330_alloc_chan_resources', so the lock is already
held. Function `pl330_release_channel' is called from
`pl330_free_chan_resources', which already holds the lock, and from
`pl330_del'. Function `pl330_del' is called in an error path of
`pl330_probe' and at the end of `pl330_remove', but I assume that there
cannot be concurrent accesses to the protected data at those points.
Signed-off-by: Iago Abal <mail@iagoabal.eu>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'include/net/inet_connection_sock.h')