2005-04-16 15:20:36 -07:00
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2005-08-08 13:52:16 -04:00
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2005-04-16 15:20:36 -07:00
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2006-09-30 20:52:18 +02:00
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2005-04-16 15:20:36 -07:00
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2006-03-26 01:37:24 -08:00
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2005-04-16 15:20:36 -07:00
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2006-07-03 00:24:34 -07:00
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2005-04-16 15:20:36 -07:00
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2006-12-06 20:33:20 -08:00
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2005-04-16 15:20:36 -07:00
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2006-03-26 01:37:24 -08:00
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2005-04-16 15:20:36 -07:00
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2006-12-06 20:38:48 -08:00
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2005-04-16 15:20:36 -07:00
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2006-12-06 20:38:48 -08:00
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2005-04-16 15:20:36 -07:00
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2006-12-06 20:38:48 -08:00
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2005-04-16 15:20:36 -07:00
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2006-01-14 13:20:43 -08:00
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2005-04-16 15:20:36 -07:00
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2005-09-19 19:54:29 -07:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:23:46 -07:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:23:46 -07:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:23:46 -07:00
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2005-04-16 15:20:36 -07:00
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[PATCH] knfsd: close a race-opportunity in d_splice_alias
There is a possible race in d_splice_alias. Though __d_find_alias(inode, 1)
will only return a dentry with DCACHE_DISCONNECTED set, it is possible for it
to get cleared before the BUG_ON, and it is is not possible to lock against
that.
There are a couple of problems here. Firstly, the code doesn't match the
comment. The comment describes a 'disconnected' dentry as being IS_ROOT as
well as DCACHE_DISCONNECTED, however there is not testing of IS_ROOT anythere.
A dentry is marked DCACHE_DISCONNECTED when allocated with d_alloc_anon, and
remains DCACHE_DISCONNECTED while a path is built up towards the root. So a
dentry can have a valid name and a valid parent and even grandparent, but will
still be DCACHE_DISCONNECTED until a path to the root is created. Once the
path to the root is complete, everything in the path gets DCACHE_DISCONNECTED
cleared. So the fact that DCACHE_DISCONNECTED isn't enough to say that a
dentry is free to be spliced in with a given name. This can only be allowed
if the dentry does not yet have a name, so the IS_ROOT test is needed too.
However even adding that test to __d_find_alias isn't enough. As
d_splice_alias drops dcache_lock before calling d_move to perform the splice,
it could race with another thread calling d_splice_alias to splice the inode
in with a different name in a different part of the tree (in the case where a
file has hard links). So that splicing code is only really safe for
directories (as we know that directories only have one link). For
directories, the caller of d_splice_alias will be holding i_mutex on the
(unique) parent so there is no room for a race.
A consequence of this is that a non-directory will never benefit from being
spliced into a pre-exisiting dentry, but that isn't a problem. It is
perfectly OK for a non-directory to have multiple dentries, some anonymous,
some not. And the comment for d_splice_alias says that it only happens for
directories anyway.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-04 02:16:16 -07:00
|
|
|
|
2005-04-16 15:20:36 -07:00
|
|
|
|
[PATCH] knfsd: close a race-opportunity in d_splice_alias
There is a possible race in d_splice_alias. Though __d_find_alias(inode, 1)
will only return a dentry with DCACHE_DISCONNECTED set, it is possible for it
to get cleared before the BUG_ON, and it is is not possible to lock against
that.
There are a couple of problems here. Firstly, the code doesn't match the
comment. The comment describes a 'disconnected' dentry as being IS_ROOT as
well as DCACHE_DISCONNECTED, however there is not testing of IS_ROOT anythere.
A dentry is marked DCACHE_DISCONNECTED when allocated with d_alloc_anon, and
remains DCACHE_DISCONNECTED while a path is built up towards the root. So a
dentry can have a valid name and a valid parent and even grandparent, but will
still be DCACHE_DISCONNECTED until a path to the root is created. Once the
path to the root is complete, everything in the path gets DCACHE_DISCONNECTED
cleared. So the fact that DCACHE_DISCONNECTED isn't enough to say that a
dentry is free to be spliced in with a given name. This can only be allowed
if the dentry does not yet have a name, so the IS_ROOT test is needed too.
However even adding that test to __d_find_alias isn't enough. As
d_splice_alias drops dcache_lock before calling d_move to perform the splice,
it could race with another thread calling d_splice_alias to splice the inode
in with a different name in a different part of the tree (in the case where a
file has hard links). So that splicing code is only really safe for
directories (as we know that directories only have one link). For
directories, the caller of d_splice_alias will be holding i_mutex on the
(unique) parent so there is no room for a race.
A consequence of this is that a non-directory will never benefit from being
spliced into a pre-exisiting dentry, but that isn't a problem. It is
perfectly OK for a non-directory to have multiple dentries, some anonymous,
some not. And the comment for d_splice_alias says that it only happens for
directories anyway.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-04 02:16:16 -07:00
|
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|
2005-04-16 15:20:36 -07:00
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|
|
[PATCH] knfsd: close a race-opportunity in d_splice_alias
There is a possible race in d_splice_alias. Though __d_find_alias(inode, 1)
will only return a dentry with DCACHE_DISCONNECTED set, it is possible for it
to get cleared before the BUG_ON, and it is is not possible to lock against
that.
There are a couple of problems here. Firstly, the code doesn't match the
comment. The comment describes a 'disconnected' dentry as being IS_ROOT as
well as DCACHE_DISCONNECTED, however there is not testing of IS_ROOT anythere.
A dentry is marked DCACHE_DISCONNECTED when allocated with d_alloc_anon, and
remains DCACHE_DISCONNECTED while a path is built up towards the root. So a
dentry can have a valid name and a valid parent and even grandparent, but will
still be DCACHE_DISCONNECTED until a path to the root is created. Once the
path to the root is complete, everything in the path gets DCACHE_DISCONNECTED
cleared. So the fact that DCACHE_DISCONNECTED isn't enough to say that a
dentry is free to be spliced in with a given name. This can only be allowed
if the dentry does not yet have a name, so the IS_ROOT test is needed too.
However even adding that test to __d_find_alias isn't enough. As
d_splice_alias drops dcache_lock before calling d_move to perform the splice,
it could race with another thread calling d_splice_alias to splice the inode
in with a different name in a different part of the tree (in the case where a
file has hard links). So that splicing code is only really safe for
directories (as we know that directories only have one link). For
directories, the caller of d_splice_alias will be holding i_mutex on the
(unique) parent so there is no room for a race.
A consequence of this is that a non-directory will never benefit from being
spliced into a pre-exisiting dentry, but that isn't a problem. It is
perfectly OK for a non-directory to have multiple dentries, some anonymous,
some not. And the comment for d_splice_alias says that it only happens for
directories anyway.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-04 02:16:16 -07:00
|
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|
2005-04-16 15:20:36 -07:00
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|
2006-03-25 03:06:36 -08:00
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2005-04-16 15:20:36 -07:00
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2005-09-10 00:27:07 -07:00
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|
2005-04-16 15:20:36 -07:00
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2005-09-10 00:27:07 -07:00
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2005-04-16 15:20:36 -07:00
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2006-06-22 14:47:31 -07:00
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2007-05-08 00:23:46 -07:00
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2005-04-16 15:20:36 -07:00
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2006-06-22 14:47:31 -07:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:23:46 -07:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:23:46 -07:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:23:46 -07:00
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2005-04-16 15:20:36 -07:00
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[PATCH] Fix dcache race during umount
The race is that the shrink_dcache_memory shrinker could get called while a
filesystem is being unmounted, and could try to prune a dentry belonging to
that filesystem.
If it does, then it will call in to iput on the inode while the dentry is
no longer able to be found by the umounting process. If iput takes a
while, generic_shutdown_super could get all the way though
shrink_dcache_parent and shrink_dcache_anon and invalidate_inodes without
ever waiting on this particular inode.
Eventually the superblock gets freed anyway and if the iput tried to touch
it (which some filesystems certainly do), it will lose. The promised
"Self-destruct in 5 seconds" doesn't lead to a nice day.
The race is closed by holding s_umount while calling prune_one_dentry on
someone else's dentry. As a down_read_trylock is used,
shrink_dcache_memory will no longer try to prune the dentry of a filesystem
that is being unmounted, and unmount will not be able to start until any
such active prune_one_dentry completes.
This requires that prune_dcache *knows* which filesystem (if any) it is
doing the prune on behalf of so that it can be careful of other
filesystems. shrink_dcache_memory isn't called it on behalf of any
filesystem, and so is careful of everything.
shrink_dcache_anon is now passed a super_block rather than the s_anon list
out of the superblock, so it can get the s_anon list itself, and can pass
the superblock down to prune_dcache.
If prune_dcache finds a dentry that it cannot free, it leaves it where it
is (at the tail of the list) and exits, on the assumption that some other
thread will be removing that dentry soon. To try to make sure that some
work gets done, a limited number of dnetries which are untouchable are
skipped over while choosing the dentry to work on.
I believe this race was first found by Kirill Korotaev.
Cc: Jan Blunck <jblunck@suse.de>
Acked-by: Kirill Korotaev <dev@openvz.org>
Cc: Olaf Hering <olh@suse.de>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Balbir Singh <balbir@in.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-22 14:47:28 -07:00
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2007-05-08 00:23:46 -07:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:23:46 -07:00
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2005-04-16 15:20:36 -07:00
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[PATCH] Fix dcache race during umount
The race is that the shrink_dcache_memory shrinker could get called while a
filesystem is being unmounted, and could try to prune a dentry belonging to
that filesystem.
If it does, then it will call in to iput on the inode while the dentry is
no longer able to be found by the umounting process. If iput takes a
while, generic_shutdown_super could get all the way though
shrink_dcache_parent and shrink_dcache_anon and invalidate_inodes without
ever waiting on this particular inode.
Eventually the superblock gets freed anyway and if the iput tried to touch
it (which some filesystems certainly do), it will lose. The promised
"Self-destruct in 5 seconds" doesn't lead to a nice day.
The race is closed by holding s_umount while calling prune_one_dentry on
someone else's dentry. As a down_read_trylock is used,
shrink_dcache_memory will no longer try to prune the dentry of a filesystem
that is being unmounted, and unmount will not be able to start until any
such active prune_one_dentry completes.
This requires that prune_dcache *knows* which filesystem (if any) it is
doing the prune on behalf of so that it can be careful of other
filesystems. shrink_dcache_memory isn't called it on behalf of any
filesystem, and so is careful of everything.
shrink_dcache_anon is now passed a super_block rather than the s_anon list
out of the superblock, so it can get the s_anon list itself, and can pass
the superblock down to prune_dcache.
If prune_dcache finds a dentry that it cannot free, it leaves it where it
is (at the tail of the list) and exits, on the assumption that some other
thread will be removing that dentry soon. To try to make sure that some
work gets done, a limited number of dnetries which are untouchable are
skipped over while choosing the dentry to work on.
I believe this race was first found by Kirill Korotaev.
Cc: Jan Blunck <jblunck@suse.de>
Acked-by: Kirill Korotaev <dev@openvz.org>
Cc: Olaf Hering <olh@suse.de>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Balbir Singh <balbir@in.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-22 14:47:28 -07:00
|
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2005-04-16 15:20:36 -07:00
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|
2006-06-25 05:49:32 -07:00
|
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|
|
[PATCH] Fix dcache race during umount
The race is that the shrink_dcache_memory shrinker could get called while a
filesystem is being unmounted, and could try to prune a dentry belonging to
that filesystem.
If it does, then it will call in to iput on the inode while the dentry is
no longer able to be found by the umounting process. If iput takes a
while, generic_shutdown_super could get all the way though
shrink_dcache_parent and shrink_dcache_anon and invalidate_inodes without
ever waiting on this particular inode.
Eventually the superblock gets freed anyway and if the iput tried to touch
it (which some filesystems certainly do), it will lose. The promised
"Self-destruct in 5 seconds" doesn't lead to a nice day.
The race is closed by holding s_umount while calling prune_one_dentry on
someone else's dentry. As a down_read_trylock is used,
shrink_dcache_memory will no longer try to prune the dentry of a filesystem
that is being unmounted, and unmount will not be able to start until any
such active prune_one_dentry completes.
This requires that prune_dcache *knows* which filesystem (if any) it is
doing the prune on behalf of so that it can be careful of other
filesystems. shrink_dcache_memory isn't called it on behalf of any
filesystem, and so is careful of everything.
shrink_dcache_anon is now passed a super_block rather than the s_anon list
out of the superblock, so it can get the s_anon list itself, and can pass
the superblock down to prune_dcache.
If prune_dcache finds a dentry that it cannot free, it leaves it where it
is (at the tail of the list) and exits, on the assumption that some other
thread will be removing that dentry soon. To try to make sure that some
work gets done, a limited number of dnetries which are untouchable are
skipped over while choosing the dentry to work on.
I believe this race was first found by Kirill Korotaev.
Cc: Jan Blunck <jblunck@suse.de>
Acked-by: Kirill Korotaev <dev@openvz.org>
Cc: Olaf Hering <olh@suse.de>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Balbir Singh <balbir@in.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-22 14:47:28 -07:00
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2005-04-16 15:20:36 -07:00
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[PATCH] Fix dcache race during umount
The race is that the shrink_dcache_memory shrinker could get called while a
filesystem is being unmounted, and could try to prune a dentry belonging to
that filesystem.
If it does, then it will call in to iput on the inode while the dentry is
no longer able to be found by the umounting process. If iput takes a
while, generic_shutdown_super could get all the way though
shrink_dcache_parent and shrink_dcache_anon and invalidate_inodes without
ever waiting on this particular inode.
Eventually the superblock gets freed anyway and if the iput tried to touch
it (which some filesystems certainly do), it will lose. The promised
"Self-destruct in 5 seconds" doesn't lead to a nice day.
The race is closed by holding s_umount while calling prune_one_dentry on
someone else's dentry. As a down_read_trylock is used,
shrink_dcache_memory will no longer try to prune the dentry of a filesystem
that is being unmounted, and unmount will not be able to start until any
such active prune_one_dentry completes.
This requires that prune_dcache *knows* which filesystem (if any) it is
doing the prune on behalf of so that it can be careful of other
filesystems. shrink_dcache_memory isn't called it on behalf of any
filesystem, and so is careful of everything.
shrink_dcache_anon is now passed a super_block rather than the s_anon list
out of the superblock, so it can get the s_anon list itself, and can pass
the superblock down to prune_dcache.
If prune_dcache finds a dentry that it cannot free, it leaves it where it
is (at the tail of the list) and exits, on the assumption that some other
thread will be removing that dentry soon. To try to make sure that some
work gets done, a limited number of dnetries which are untouchable are
skipped over while choosing the dentry to work on.
I believe this race was first found by Kirill Korotaev.
Cc: Jan Blunck <jblunck@suse.de>
Acked-by: Kirill Korotaev <dev@openvz.org>
Cc: Olaf Hering <olh@suse.de>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Balbir Singh <balbir@in.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-22 14:47:28 -07:00
|
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2007-05-08 00:23:46 -07:00
|
|
|
|
[PATCH] Fix dcache race during umount
The race is that the shrink_dcache_memory shrinker could get called while a
filesystem is being unmounted, and could try to prune a dentry belonging to
that filesystem.
If it does, then it will call in to iput on the inode while the dentry is
no longer able to be found by the umounting process. If iput takes a
while, generic_shutdown_super could get all the way though
shrink_dcache_parent and shrink_dcache_anon and invalidate_inodes without
ever waiting on this particular inode.
Eventually the superblock gets freed anyway and if the iput tried to touch
it (which some filesystems certainly do), it will lose. The promised
"Self-destruct in 5 seconds" doesn't lead to a nice day.
The race is closed by holding s_umount while calling prune_one_dentry on
someone else's dentry. As a down_read_trylock is used,
shrink_dcache_memory will no longer try to prune the dentry of a filesystem
that is being unmounted, and unmount will not be able to start until any
such active prune_one_dentry completes.
This requires that prune_dcache *knows* which filesystem (if any) it is
doing the prune on behalf of so that it can be careful of other
filesystems. shrink_dcache_memory isn't called it on behalf of any
filesystem, and so is careful of everything.
shrink_dcache_anon is now passed a super_block rather than the s_anon list
out of the superblock, so it can get the s_anon list itself, and can pass
the superblock down to prune_dcache.
If prune_dcache finds a dentry that it cannot free, it leaves it where it
is (at the tail of the list) and exits, on the assumption that some other
thread will be removing that dentry soon. To try to make sure that some
work gets done, a limited number of dnetries which are untouchable are
skipped over while choosing the dentry to work on.
I believe this race was first found by Kirill Korotaev.
Cc: Jan Blunck <jblunck@suse.de>
Acked-by: Kirill Korotaev <dev@openvz.org>
Cc: Olaf Hering <olh@suse.de>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Balbir Singh <balbir@in.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-22 14:47:28 -07:00
|
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|
2007-05-08 00:23:46 -07:00
|
|
|
|
[PATCH] Fix dcache race during umount
The race is that the shrink_dcache_memory shrinker could get called while a
filesystem is being unmounted, and could try to prune a dentry belonging to
that filesystem.
If it does, then it will call in to iput on the inode while the dentry is
no longer able to be found by the umounting process. If iput takes a
while, generic_shutdown_super could get all the way though
shrink_dcache_parent and shrink_dcache_anon and invalidate_inodes without
ever waiting on this particular inode.
Eventually the superblock gets freed anyway and if the iput tried to touch
it (which some filesystems certainly do), it will lose. The promised
"Self-destruct in 5 seconds" doesn't lead to a nice day.
The race is closed by holding s_umount while calling prune_one_dentry on
someone else's dentry. As a down_read_trylock is used,
shrink_dcache_memory will no longer try to prune the dentry of a filesystem
that is being unmounted, and unmount will not be able to start until any
such active prune_one_dentry completes.
This requires that prune_dcache *knows* which filesystem (if any) it is
doing the prune on behalf of so that it can be careful of other
filesystems. shrink_dcache_memory isn't called it on behalf of any
filesystem, and so is careful of everything.
shrink_dcache_anon is now passed a super_block rather than the s_anon list
out of the superblock, so it can get the s_anon list itself, and can pass
the superblock down to prune_dcache.
If prune_dcache finds a dentry that it cannot free, it leaves it where it
is (at the tail of the list) and exits, on the assumption that some other
thread will be removing that dentry soon. To try to make sure that some
work gets done, a limited number of dnetries which are untouchable are
skipped over while choosing the dentry to work on.
I believe this race was first found by Kirill Korotaev.
Cc: Jan Blunck <jblunck@suse.de>
Acked-by: Kirill Korotaev <dev@openvz.org>
Cc: Olaf Hering <olh@suse.de>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Balbir Singh <balbir@in.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-22 14:47:28 -07:00
|
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2006-10-28 10:38:44 -07:00
|
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|
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|
|
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|
|
|
|
|
[PATCH] Fix dcache race during umount
The race is that the shrink_dcache_memory shrinker could get called while a
filesystem is being unmounted, and could try to prune a dentry belonging to
that filesystem.
If it does, then it will call in to iput on the inode while the dentry is
no longer able to be found by the umounting process. If iput takes a
while, generic_shutdown_super could get all the way though
shrink_dcache_parent and shrink_dcache_anon and invalidate_inodes without
ever waiting on this particular inode.
Eventually the superblock gets freed anyway and if the iput tried to touch
it (which some filesystems certainly do), it will lose. The promised
"Self-destruct in 5 seconds" doesn't lead to a nice day.
The race is closed by holding s_umount while calling prune_one_dentry on
someone else's dentry. As a down_read_trylock is used,
shrink_dcache_memory will no longer try to prune the dentry of a filesystem
that is being unmounted, and unmount will not be able to start until any
such active prune_one_dentry completes.
This requires that prune_dcache *knows* which filesystem (if any) it is
doing the prune on behalf of so that it can be careful of other
filesystems. shrink_dcache_memory isn't called it on behalf of any
filesystem, and so is careful of everything.
shrink_dcache_anon is now passed a super_block rather than the s_anon list
out of the superblock, so it can get the s_anon list itself, and can pass
the superblock down to prune_dcache.
If prune_dcache finds a dentry that it cannot free, it leaves it where it
is (at the tail of the list) and exits, on the assumption that some other
thread will be removing that dentry soon. To try to make sure that some
work gets done, a limited number of dnetries which are untouchable are
skipped over while choosing the dentry to work on.
I believe this race was first found by Kirill Korotaev.
Cc: Jan Blunck <jblunck@suse.de>
Acked-by: Kirill Korotaev <dev@openvz.org>
Cc: Olaf Hering <olh@suse.de>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Balbir Singh <balbir@in.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-22 14:47:28 -07:00
|
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|
2006-10-28 10:38:44 -07:00
|
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2005-04-16 15:20:36 -07:00
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2005-09-10 00:27:07 -07:00
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2005-04-16 15:20:36 -07:00
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2006-06-26 00:24:40 -07:00
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2005-04-16 15:20:36 -07:00
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2005-09-10 00:27:07 -07:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:23:46 -07:00
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2006-03-25 03:07:45 -08:00
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2005-04-16 15:20:36 -07:00
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2006-10-11 01:22:19 -07:00
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2006-10-28 10:38:46 -07:00
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2006-10-11 01:22:19 -07:00
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2006-10-28 10:38:46 -07:00
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2006-10-11 01:22:19 -07:00
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2006-10-28 10:38:46 -07:00
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2006-10-11 01:22:19 -07:00
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2006-10-28 10:38:46 -07:00
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2006-10-11 01:22:19 -07:00
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2005-04-16 15:20:36 -07:00
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[PATCH] shrink dentry struct
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:03:32 -08:00
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2005-04-16 15:20:36 -07:00
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|
[PATCH] shrink dentry struct
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:03:32 -08:00
|
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|
2005-04-16 15:20:36 -07:00
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|
[PATCH] shrink dentry struct
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:03:32 -08:00
|
|
|
|
2005-04-16 15:20:36 -07:00
|
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|
2006-06-26 00:24:37 -07:00
|
|
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|
2005-04-16 15:20:36 -07:00
|
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|
[PATCH] shrink dentry struct
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:03:32 -08:00
|
|
|
|
2005-04-16 15:20:36 -07:00
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2007-05-08 00:23:46 -07:00
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2005-04-16 15:20:36 -07:00
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2005-10-21 03:20:48 -04:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:23:49 -07:00
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2005-04-16 15:20:36 -07:00
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2007-07-17 04:03:17 -07:00
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2005-04-16 15:20:36 -07:00
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2006-02-03 03:04:06 -08:00
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2005-04-16 15:20:36 -07:00
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2006-02-03 03:04:06 -08:00
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2005-04-16 15:20:36 -07:00
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[PATCH] shrink dentry struct
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:03:32 -08:00
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2005-04-16 15:20:36 -07:00
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[PATCH] shrink dentry struct
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:03:32 -08:00
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2005-04-16 15:20:36 -07:00
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2006-03-26 18:25:39 +02:00
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2005-04-16 15:20:36 -07:00
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2006-03-25 03:07:09 -08:00
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2005-04-16 15:20:36 -07:00
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2006-01-09 20:52:51 -08:00
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2005-04-16 15:20:36 -07:00
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2006-01-09 20:52:51 -08:00
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2005-04-16 15:20:36 -07:00
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2006-08-22 20:06:07 -04:00
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2005-04-16 15:20:36 -07:00
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2006-08-22 20:06:07 -04:00
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2005-04-16 15:20:36 -07:00
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2006-08-22 20:06:07 -04:00
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2005-04-16 15:20:36 -07:00
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2006-03-25 03:07:09 -08:00
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2005-04-16 15:20:36 -07:00
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2006-08-22 20:06:07 -04:00
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2005-04-16 15:20:36 -07:00
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[PATCH] knfsd: close a race-opportunity in d_splice_alias
There is a possible race in d_splice_alias. Though __d_find_alias(inode, 1)
will only return a dentry with DCACHE_DISCONNECTED set, it is possible for it
to get cleared before the BUG_ON, and it is is not possible to lock against
that.
There are a couple of problems here. Firstly, the code doesn't match the
comment. The comment describes a 'disconnected' dentry as being IS_ROOT as
well as DCACHE_DISCONNECTED, however there is not testing of IS_ROOT anythere.
A dentry is marked DCACHE_DISCONNECTED when allocated with d_alloc_anon, and
remains DCACHE_DISCONNECTED while a path is built up towards the root. So a
dentry can have a valid name and a valid parent and even grandparent, but will
still be DCACHE_DISCONNECTED until a path to the root is created. Once the
path to the root is complete, everything in the path gets DCACHE_DISCONNECTED
cleared. So the fact that DCACHE_DISCONNECTED isn't enough to say that a
dentry is free to be spliced in with a given name. This can only be allowed
if the dentry does not yet have a name, so the IS_ROOT test is needed too.
However even adding that test to __d_find_alias isn't enough. As
d_splice_alias drops dcache_lock before calling d_move to perform the splice,
it could race with another thread calling d_splice_alias to splice the inode
in with a different name in a different part of the tree (in the case where a
file has hard links). So that splicing code is only really safe for
directories (as we know that directories only have one link). For
directories, the caller of d_splice_alias will be holding i_mutex on the
(unique) parent so there is no room for a race.
A consequence of this is that a non-directory will never benefit from being
spliced into a pre-exisiting dentry, but that isn't a problem. It is
perfectly OK for a non-directory to have multiple dentries, some anonymous,
some not. And the comment for d_splice_alias says that it only happens for
directories anyway.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-04 02:16:16 -07:00
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2005-04-16 15:20:36 -07:00
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2006-03-25 03:07:09 -08:00
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2005-04-16 15:20:36 -07:00
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2006-03-25 03:07:09 -08:00
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2005-04-16 15:20:36 -07:00
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2005-11-07 00:59:17 -08:00
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2005-04-16 15:20:36 -07:00
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2005-11-07 00:59:17 -08:00
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2005-04-16 15:20:36 -07:00
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2006-03-31 02:31:43 -08:00
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2005-04-16 15:20:36 -07:00
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2005-11-07 00:59:17 -08:00
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2005-04-16 15:20:36 -07:00
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2005-08-08 13:52:16 -04:00
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2005-04-16 15:20:36 -07:00
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2005-08-08 13:52:16 -04:00
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2005-04-16 15:20:36 -07:00
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2005-08-08 13:52:16 -04:00
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2006-03-31 02:30:54 -08:00
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2005-04-16 15:20:36 -07:00
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2005-08-08 13:52:16 -04:00
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2005-04-16 15:20:36 -07:00
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2006-08-22 20:06:07 -04:00
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2005-04-16 15:20:36 -07:00
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2006-08-22 20:06:07 -04:00
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2005-04-16 15:20:36 -07:00
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2006-10-21 10:24:20 -07:00
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2005-04-16 15:20:36 -07:00
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2006-10-21 10:24:20 -07:00
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2005-04-16 15:20:36 -07:00
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2006-07-03 00:25:04 -07:00
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2005-04-16 15:20:36 -07:00
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2006-07-03 00:25:04 -07:00
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2005-04-16 15:20:36 -07:00
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[PATCH] shrink dentry struct
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:03:32 -08:00
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2005-04-16 15:20:36 -07:00
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[PATCH] shrink dentry struct
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:03:32 -08:00
|
|
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|
2005-04-16 15:20:36 -07:00
|
|
|
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|
|
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|
[PATCH] shrink dentry struct
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:03:32 -08:00
|
|
|
|
2005-04-16 15:20:36 -07:00
|
|
|
|
|
|
|
|
|
[PATCH] shrink dentry struct
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:03:32 -08:00
|
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|
2005-04-16 15:20:36 -07:00
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|
2006-03-25 03:07:09 -08:00
|
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|
2005-04-16 15:20:36 -07:00
|
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2006-10-21 10:24:20 -07:00
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2005-04-16 15:20:36 -07:00
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2006-10-21 10:24:20 -07:00
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2006-08-22 20:06:07 -04:00
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2006-10-21 10:24:20 -07:00
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2006-08-22 20:06:07 -04:00
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2006-10-21 10:24:20 -07:00
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2006-08-22 20:06:07 -04:00
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2006-10-21 10:24:20 -07:00
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2006-08-22 20:06:07 -04:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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[PATCH] Fix d_path for lazy unmounts
Here is a bugfix to d_path.
First, when d_path() hits a lazily unmounted mount point, it tries to
prepend the name of the lazily unmounted dentry to the path name. It gets
this wrong, and also overwrites the slash that separates the name from the
following pathname component. This is demonstrated by the attached test
case, which prints "getcwd returned d_path-bugsubdir" with the bug. The
correct result would be "getcwd returned d_path-bug/subdir".
It could be argued that the name of the root dentry should not be part of
the result of d_path in the first place. On the other hand, what the
unconnected namespace was once reachable as may provide some useful hints
to users, and so that seems okay.
Second, it isn't always possible to tell from the __d_path result whether
the specified root and rootmnt (i.e., the chroot) was reached: lazy
unmounts of bind mounts will produce a path that does start with a
non-slash so we can tell from that, but other lazy unmounts will produce a
path that starts with a slash, just like "ordinary" paths.
The attached patch cleans up __d_path() to fix the bug with overlapping
pathname components. It also adds a @fail_deleted argument, which allows
to get rid of some of the mess in sys_getcwd(). Grabbing the dcache_lock
can then also be moved into __d_path(). The patch also makes sure that
paths will only start with a slash for paths which are connected to the
root and rootmnt.
The @fail_deleted argument could be added to d_path() as well: this would
allow callers to recognize deleted files, without having to resort to the
ambiguous check for the " (deleted)" string at the end of the pathnames.
This is not currently done, but it might be worthwhile.
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Cc: Neil Brown <neilb@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 00:51:47 -08:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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[PATCH] Fix d_path for lazy unmounts
Here is a bugfix to d_path.
First, when d_path() hits a lazily unmounted mount point, it tries to
prepend the name of the lazily unmounted dentry to the path name. It gets
this wrong, and also overwrites the slash that separates the name from the
following pathname component. This is demonstrated by the attached test
case, which prints "getcwd returned d_path-bugsubdir" with the bug. The
correct result would be "getcwd returned d_path-bug/subdir".
It could be argued that the name of the root dentry should not be part of
the result of d_path in the first place. On the other hand, what the
unconnected namespace was once reachable as may provide some useful hints
to users, and so that seems okay.
Second, it isn't always possible to tell from the __d_path result whether
the specified root and rootmnt (i.e., the chroot) was reached: lazy
unmounts of bind mounts will produce a path that does start with a
non-slash so we can tell from that, but other lazy unmounts will produce a
path that starts with a slash, just like "ordinary" paths.
The attached patch cleans up __d_path() to fix the bug with overlapping
pathname components. It also adds a @fail_deleted argument, which allows
to get rid of some of the mess in sys_getcwd(). Grabbing the dcache_lock
can then also be moved into __d_path(). The patch also makes sure that
paths will only start with a slash for paths which are connected to the
root and rootmnt.
The @fail_deleted argument could be added to d_path() as well: this would
allow callers to recognize deleted files, without having to resort to the
ambiguous check for the " (deleted)" string at the end of the pathnames.
This is not currently done, but it might be worthwhile.
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Cc: Neil Brown <neilb@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 00:51:47 -08:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:26:18 -07:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:26:18 -07:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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2007-02-13 12:08:18 -08:00
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2005-04-16 15:20:36 -07:00
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[PATCH] shrink dentry struct
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:03:32 -08:00
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2005-04-16 15:20:36 -07:00
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[PATCH] shrink dentry struct
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:03:32 -08:00
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2005-04-16 15:20:36 -07:00
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2006-03-31 02:31:43 -08:00
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2005-04-16 15:20:36 -07:00
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2007-05-06 14:49:57 -07:00
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2005-04-16 15:20:36 -07:00
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2007-07-17 04:03:17 -07:00
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2005-04-16 15:20:36 -07:00
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2006-12-06 20:33:20 -08:00
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2005-04-16 15:20:36 -07:00
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2006-12-06 20:33:20 -08:00
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2005-04-16 15:20:36 -07:00
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2007-07-20 10:11:58 +09:00
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2005-04-16 15:20:36 -07:00
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2007-07-20 10:11:58 +09:00
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2005-04-16 15:20:36 -07:00
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2006-08-22 20:06:07 -04:00
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2005-04-16 15:20:36 -07:00
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