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fanotify: do not call fanotify_update_object_mask in fanotify_add_mark
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Recalculate masks in fanotify_add_mark, don't use
fanotify_update_object_mask.  This gets us one step closers to readable
code.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
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Andreas Gruenbacher authored and Eric Paris committed Jul 28, 2010
1 parent 088b09b commit 912ee39
Showing 1 changed file with 50 additions and 94 deletions.
144 changes: 50 additions & 94 deletions fs/notify/fanotify/fanotify_user.c
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Original file line number Diff line number Diff line change
Expand Up @@ -295,64 +295,6 @@ static int fanotify_find_path(int dfd, const char __user *filename,
return ret;
}

static void fanotify_update_object_mask(struct fsnotify_group *group,
struct inode *inode,
struct vfsmount *mnt,
struct fsnotify_mark *fsn_mark,
unsigned int flags,
__u32 mask)
{
__u32 old_mask, new_mask;

pr_debug("%s: group=%p inode=%p mnt=%p fsn_mark=%p flags=%x mask=%x\n",
__func__, group, inode, mnt, fsn_mark, flags, mask);

spin_lock(&fsn_mark->lock);
old_mask = fsn_mark->mask;
if (flags & FAN_MARK_ADD)
fsn_mark->mask |= mask;
else if (flags & FAN_MARK_REMOVE)
fsn_mark->mask &= ~mask;
else
BUG();
new_mask = fsn_mark->mask;
spin_unlock(&fsn_mark->lock);

if (!new_mask)
fsnotify_destroy_mark(fsn_mark);

/* we made changes to a mask, update the group mask and the object mask
* so things happen quickly. */
if (old_mask != new_mask) {
__u32 dropped, do_object, do_group;

/* more bits in old than in new? */
dropped = (old_mask & ~new_mask);
/* more bits in this fsn_mark than the group? */
do_group = (new_mask & ~group->mask);

if (inode) {
/* more bits in this fsn_mark than the object's mask? */
do_object = (new_mask & ~inode->i_fsnotify_mask);
/* update the object with this new fsn_mark */
if (dropped || do_object)
fsnotify_recalc_inode_mask(inode);
} else if (mnt) {
/* more bits in this fsn_mark than the object's mask? */
do_object = (new_mask & ~mnt->mnt_fsnotify_mask);
/* update the object with this new fsn_mark */
if (dropped || do_object)
fsnotify_recalc_vfsmount_mask(mnt);
} else {
BUG();
}

/* update the group mask with the new mask */
if (dropped || do_group)
fsnotify_recalc_group_mask(group);
}
}

static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark, __u32 mask)
{
__u32 oldmask;
Expand Down Expand Up @@ -404,89 +346,103 @@ static int fanotify_remove_mark(struct fsnotify_group *group, struct inode *inod
return 0;
}

static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark, __u32 mask)
{
__u32 oldmask;

spin_lock(&fsn_mark->lock);
oldmask = fsn_mark->mask;
fsn_mark->mask = oldmask | mask;
spin_unlock(&fsn_mark->lock);

return mask & ~oldmask;
}

static struct fsnotify_mark *fanotify_add_vfsmount_mark(struct fsnotify_group *group,
struct vfsmount *mnt)
struct vfsmount *mnt, __u32 mask)
{
struct fsnotify_mark *fsn_mark;
__u32 added;

fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
if (!fsn_mark) {
struct fsnotify_mark *new_fsn_mark;
int ret;

fsn_mark = ERR_PTR(-ENOMEM);
new_fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
if (!new_fsn_mark)
goto out;
fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
if (!fsn_mark)
return ERR_PTR(-ENOMEM);

fsnotify_init_mark(new_fsn_mark, fanotify_free_mark);
ret = fsnotify_add_mark(new_fsn_mark, group, NULL, mnt, 0);
fsnotify_init_mark(fsn_mark, fanotify_free_mark);
ret = fsnotify_add_mark(fsn_mark, group, NULL, mnt, 0);
if (ret) {
fsn_mark = ERR_PTR(ret);
fanotify_free_mark(new_fsn_mark);
goto out;
fanotify_free_mark(fsn_mark);
return ERR_PTR(ret);
}

fsn_mark = new_fsn_mark;
}
out:
added = fanotify_mark_add_to_mask(fsn_mark, mask);
if (added) {
if (added & ~group->mask)
fsnotify_recalc_group_mask(group);
if (added & ~mnt->mnt_fsnotify_mask)
fsnotify_recalc_vfsmount_mask(mnt);
}
return fsn_mark;
}

static struct fsnotify_mark *fanotify_add_inode_mark(struct fsnotify_group *group,
struct inode *inode)
struct inode *inode, __u32 mask)
{
struct fsnotify_mark *fsn_mark;
__u32 added;

pr_debug("%s: group=%p inode=%p\n", __func__, group, inode);

fsn_mark = fsnotify_find_inode_mark(group, inode);
if (!fsn_mark) {
struct fsnotify_mark *new_fsn_mark;
int ret;

fsn_mark = ERR_PTR(-ENOMEM);
new_fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
if (!new_fsn_mark)
goto out;
fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
if (!fsn_mark)
return ERR_PTR(-ENOMEM);

fsnotify_init_mark(new_fsn_mark, fanotify_free_mark);
ret = fsnotify_add_mark(new_fsn_mark, group, inode, NULL, 0);
fsnotify_init_mark(fsn_mark, fanotify_free_mark);
ret = fsnotify_add_mark(fsn_mark, group, inode, NULL, 0);
if (ret) {
fsn_mark = ERR_PTR(ret);
fanotify_free_mark(new_fsn_mark);
goto out;
fanotify_free_mark(fsn_mark);
return ERR_PTR(ret);
}

fsn_mark = new_fsn_mark;
}
out:
added = fanotify_mark_add_to_mask(fsn_mark, mask);
if (added) {
if (added & ~group->mask)
fsnotify_recalc_group_mask(group);
if (added & ~inode->i_fsnotify_mask)
fsnotify_recalc_inode_mask(inode);
}
return fsn_mark;
}

static int fanotify_add_mark(struct fsnotify_group *group, struct inode *inode,
struct vfsmount *mnt, unsigned int flags, __u32 mask)
struct vfsmount *mnt, __u32 mask)
{
struct fsnotify_mark *fsn_mark;

pr_debug("%s: group=%p inode=%p mnt=%p flags=%x mask=%x\n",
__func__, group, inode, mnt, flags, mask);
pr_debug("%s: group=%p inode=%p mnt=%p mask=%x\n",
__func__, group, inode, mnt, mask);

BUG_ON(inode && mnt);
BUG_ON(!inode && !mnt);

if (inode)
fsn_mark = fanotify_add_inode_mark(group, inode);
fsn_mark = fanotify_add_inode_mark(group, inode, mask);
else if (mnt)
fsn_mark = fanotify_add_vfsmount_mark(group, mnt);
fsn_mark = fanotify_add_vfsmount_mark(group, mnt, mask);
else
BUG();

if (IS_ERR(fsn_mark))
goto out;

fanotify_update_object_mask(group, inode, mnt, fsn_mark, flags, mask);

/* match the init or the find.... */
fsnotify_put_mark(fsn_mark);
out:
Expand Down Expand Up @@ -590,7 +546,7 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags,
/* create/update an inode mark */
switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE)) {
case FAN_MARK_ADD:
ret = fanotify_add_mark(group, inode, NULL, flags, mask);
ret = fanotify_add_mark(group, inode, NULL, mask);
break;
case FAN_MARK_REMOVE:
ret = fanotify_remove_mark(group, inode, NULL, mask);
Expand Down

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