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author | Al Viro <viro@zeniv.linux.org.uk> | 2013-03-30 20:13:46 -0400 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2013-04-09 14:09:17 -0400 |
commit | 8ce584c7416d8a85a6f3edc17d1cddefe331e87e (patch) | |
tree | 4fe64bd588ba8e2239cfa893e1bddb3e3b30c232 /fs | |
parent | 52f21999c7b921a0390708b66ed286282c2e4bee (diff) | |
download | lwn-8ce584c7416d8a85a6f3edc17d1cddefe331e87e.tar.gz lwn-8ce584c7416d8a85a6f3edc17d1cddefe331e87e.zip |
procfs: add proc_remove_subtree()
just what it sounds like; do that only to procfs subtrees you've
created - doing that to something shared with another driver is
not only antisocial, but might cause interesting races with
proc_create() and its ilk.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/proc/generic.c | 119 |
1 files changed, 89 insertions, 30 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 4b3b3ffb52f1..21e1a8f1659d 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -755,37 +755,8 @@ void pde_put(struct proc_dir_entry *pde) free_proc_entry(pde); } -/* - * Remove a /proc entry and free it if it's not currently in use. - */ -void remove_proc_entry(const char *name, struct proc_dir_entry *parent) +static void entry_rundown(struct proc_dir_entry *de) { - struct proc_dir_entry **p; - struct proc_dir_entry *de = NULL; - const char *fn = name; - unsigned int len; - - spin_lock(&proc_subdir_lock); - if (__xlate_proc_name(name, &parent, &fn) != 0) { - spin_unlock(&proc_subdir_lock); - return; - } - len = strlen(fn); - - for (p = &parent->subdir; *p; p=&(*p)->next ) { - if (proc_match(len, fn, *p)) { - de = *p; - *p = de->next; - de->next = NULL; - break; - } - } - spin_unlock(&proc_subdir_lock); - if (!de) { - WARN(1, "name '%s'\n", name); - return; - } - spin_lock(&de->pde_unload_lock); /* * Stop accepting new callers into module. If you're @@ -817,6 +788,40 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent) spin_lock(&de->pde_unload_lock); } spin_unlock(&de->pde_unload_lock); +} + +/* + * Remove a /proc entry and free it if it's not currently in use. + */ +void remove_proc_entry(const char *name, struct proc_dir_entry *parent) +{ + struct proc_dir_entry **p; + struct proc_dir_entry *de = NULL; + const char *fn = name; + unsigned int len; + + spin_lock(&proc_subdir_lock); + if (__xlate_proc_name(name, &parent, &fn) != 0) { + spin_unlock(&proc_subdir_lock); + return; + } + len = strlen(fn); + + for (p = &parent->subdir; *p; p=&(*p)->next ) { + if (proc_match(len, fn, *p)) { + de = *p; + *p = de->next; + de->next = NULL; + break; + } + } + spin_unlock(&proc_subdir_lock); + if (!de) { + WARN(1, "name '%s'\n", name); + return; + } + + entry_rundown(de); if (S_ISDIR(de->mode)) parent->nlink--; @@ -827,3 +832,57 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent) pde_put(de); } EXPORT_SYMBOL(remove_proc_entry); + +int remove_proc_subtree(const char *name, struct proc_dir_entry *parent) +{ + struct proc_dir_entry **p; + struct proc_dir_entry *root = NULL, *de, *next; + const char *fn = name; + unsigned int len; + + spin_lock(&proc_subdir_lock); + if (__xlate_proc_name(name, &parent, &fn) != 0) { + spin_unlock(&proc_subdir_lock); + return -ENOENT; + } + len = strlen(fn); + + for (p = &parent->subdir; *p; p=&(*p)->next ) { + if (proc_match(len, fn, *p)) { + root = *p; + *p = root->next; + root->next = NULL; + break; + } + } + if (!root) { + spin_unlock(&proc_subdir_lock); + return -ENOENT; + } + de = root; + while (1) { + next = de->subdir; + if (next) { + de->subdir = next->next; + next->next = NULL; + de = next; + continue; + } + spin_unlock(&proc_subdir_lock); + + entry_rundown(de); + next = de->parent; + if (S_ISDIR(de->mode)) + next->nlink--; + de->nlink = 0; + if (de == root) + break; + pde_put(de); + + spin_lock(&proc_subdir_lock); + de = next; + } + pde_put(root); + return 0; +} +EXPORT_SYMBOL(remove_proc_subtree); |