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| author | Theodore Ts'o <tytso@mit.edu> | 2009-05-21 16:01:00 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2009-06-11 21:36:09 -0400 |
| commit | 9fd5746fd3d7838bf6ff991d50f1257057d1156f (patch) | |
| tree | e0afe14ea9415b0e54c40703bb44acfec100a4b3 /drivers/ieee1394 | |
| parent | ebc1ac164560a241d9bf1b7519062910c3f90a01 (diff) | |
| download | lwn-9fd5746fd3d7838bf6ff991d50f1257057d1156f.tar.gz lwn-9fd5746fd3d7838bf6ff991d50f1257057d1156f.zip | |
fs: Remove i_cindex from struct inode
The only user of the i_cindex element in the inode structure is used
is by the firewire drivers. As part of an attempt to slim down the
inode structure to save memory --- since a typical Linux system will
have hundreds of thousands if not millions of inodes cached, a
reduction in the size inode has high leverage.
The firewire driver does not need i_cindex in any fast path, so it's
simple enough to calculate when it is needed, instead of wasting space
in the inode structure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: krh@redhat.com
Cc: stefanr@s5r6.in-berlin.de
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'drivers/ieee1394')
| -rw-r--r-- | drivers/ieee1394/dv1394.c | 5 | ||||
| -rw-r--r-- | drivers/ieee1394/ieee1394_core.h | 6 |
2 files changed, 8 insertions, 3 deletions
diff --git a/drivers/ieee1394/dv1394.c b/drivers/ieee1394/dv1394.c index 823a6297a1af..2cd00b5b45b4 100644 --- a/drivers/ieee1394/dv1394.c +++ b/drivers/ieee1394/dv1394.c @@ -1789,12 +1789,13 @@ static int dv1394_open(struct inode *inode, struct file *file) } else { /* look up the card by ID */ unsigned long flags; + int idx = ieee1394_file_to_instance(file); spin_lock_irqsave(&dv1394_cards_lock, flags); if (!list_empty(&dv1394_cards)) { struct video_card *p; list_for_each_entry(p, &dv1394_cards, list) { - if ((p->id) == ieee1394_file_to_instance(file)) { + if ((p->id) == idx) { video = p; break; } @@ -1803,7 +1804,7 @@ static int dv1394_open(struct inode *inode, struct file *file) spin_unlock_irqrestore(&dv1394_cards_lock, flags); if (!video) { - debug_printk("dv1394: OHCI card %d not found", ieee1394_file_to_instance(file)); + debug_printk("dv1394: OHCI card %d not found", idx); return -ENODEV; } diff --git a/drivers/ieee1394/ieee1394_core.h b/drivers/ieee1394/ieee1394_core.h index 21d50f73a210..28b9f58bafd2 100644 --- a/drivers/ieee1394/ieee1394_core.h +++ b/drivers/ieee1394/ieee1394_core.h @@ -5,6 +5,7 @@ #include <linux/fs.h> #include <linux/list.h> #include <linux/types.h> +#include <linux/cdev.h> #include <asm/atomic.h> #include "hosts.h" @@ -155,7 +156,10 @@ void hpsb_packet_received(struct hpsb_host *host, quadlet_t *data, size_t size, */ static inline unsigned char ieee1394_file_to_instance(struct file *file) { - return file->f_path.dentry->d_inode->i_cindex; + int idx = cdev_index(file->f_path.dentry->d_inode); + if (idx < 0) + idx = 0; + return idx; } extern int hpsb_disable_irm; |