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"[PATCH 0/3] RFC - module.h usage cleanups in fs/ and lib/" https://lkml.org/lkml/2012/2/29/589 -- Fix up files in fs/ and lib/ dirs to only use module.h if they really need it. These are trivial in scope vs. the work done previously. We now have things where any few remaining cleanups can be farmed out to arch or subsystem maintainers, and I have done so when possible. What is remaining here represents the bits that don't clearly lie within a single arch/subsystem boundary, like the fs dir and the lib dir. Some duplicate includes arising from overlapping fixes from independent subsystem maintainer submissions are also quashed. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAABAgAGBQJPbNw3AAoJEOvOhAQsB9HWA7wQALrsQ6V6Z+B3KsvSoD5kFnpZ Y+4uggs+GdUdWmtRrZnTBp896gGuUgBxc3syA2XWd7Oqi49+c5c1m0cFxKyVdIHm fB+jmxS69soADtHR3cXmxcQshrUzUf2rTn8frcw4O/BmJuplv4xT9uPQzwGaRSZT gomQsQ1bGnkwjO2jfS8f/N5Mjr8u/z0WF7TTOTUSq+Cv3BervPaSPF1Ea6J8oo+N 4+/n8RlU1HWiI4inrgrFPN6UHmE45BAL2xGbB47LgooHJW8P5kAnU+vxGScaoy1Q JKX9WKT3VCiwR3VOPa86iLKP3Y8a3VlhyGn+yzzcYkGX/n0tbT7aoRhQm21sGIv0 DoeXWe7aiiY8cEW69G6GIfRPFl+Zh81m1Whbu7IZT/sV3asx6jWmEXE8CgCfeDt5 mNQk9D4Irf6+rmCSbeSVC4L0eFfLxNFouNyh2aus/q+gIjKNKYwZQryHrodK4wpv UgMKSTZfPrTAWay2gCNWNqo3Zs8e1LDqkftetxeU3jx2kTuaNzBl4Y7mhsX7sLYe MsFX3JUJ2pn6XWbgqcY+bdr/mzgsCrjzqdf15MTUzEc5SIfVF+XpNNZN1ITwl6UA /ZH9keBu1mEdCoPU5W74kYwx4p35hIeWJGfc0MRp07ruf941F+SBgMD11B0+06f0 pN0DcITTkD16+sS4x1cB =Z4w0 -----END PGP SIGNATURE----- Merge tag 'module-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull cleanup of fs/ and lib/ users of module.h from Paul Gortmaker: "Fix up files in fs/ and lib/ dirs to only use module.h if they really need it. These are trivial in scope vs the work done previously. We now have things where any few remaining cleanups can be farmed out to arch or subsystem maintainers, and I have done so when possible. What is remaining here represents the bits that don't clearly lie within a single arch/subsystem boundary, like the fs dir and the lib dir. Some duplicate includes arising from overlapping fixes from independent subsystem maintainer submissions are also quashed." Fix up trivial conflicts due to clashes with other include file cleanups (including some due to the previous bug.h cleanup pull). * tag 'module-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: lib: reduce the use of module.h wherever possible fs: reduce the use of module.h wherever possible includecheck: delete any duplicate instances of module.h
202 lines
3.9 KiB
C
202 lines
3.9 KiB
C
#include <linux/export.h>
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#include <linux/sched.h>
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#include <linux/fs.h>
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#include <linux/path.h>
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#include <linux/slab.h>
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#include <linux/fs_struct.h>
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#include "internal.h"
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static inline void path_get_longterm(struct path *path)
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{
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path_get(path);
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mnt_make_longterm(path->mnt);
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}
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static inline void path_put_longterm(struct path *path)
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{
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mnt_make_shortterm(path->mnt);
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path_put(path);
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}
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/*
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* Replace the fs->{rootmnt,root} with {mnt,dentry}. Put the old values.
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* It can block.
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*/
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void set_fs_root(struct fs_struct *fs, struct path *path)
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{
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struct path old_root;
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path_get_longterm(path);
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spin_lock(&fs->lock);
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write_seqcount_begin(&fs->seq);
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old_root = fs->root;
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fs->root = *path;
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write_seqcount_end(&fs->seq);
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spin_unlock(&fs->lock);
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if (old_root.dentry)
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path_put_longterm(&old_root);
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}
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/*
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* Replace the fs->{pwdmnt,pwd} with {mnt,dentry}. Put the old values.
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* It can block.
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*/
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void set_fs_pwd(struct fs_struct *fs, struct path *path)
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{
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struct path old_pwd;
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path_get_longterm(path);
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spin_lock(&fs->lock);
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write_seqcount_begin(&fs->seq);
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old_pwd = fs->pwd;
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fs->pwd = *path;
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write_seqcount_end(&fs->seq);
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spin_unlock(&fs->lock);
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if (old_pwd.dentry)
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path_put_longterm(&old_pwd);
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}
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static inline int replace_path(struct path *p, const struct path *old, const struct path *new)
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{
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if (likely(p->dentry != old->dentry || p->mnt != old->mnt))
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return 0;
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*p = *new;
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return 1;
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}
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void chroot_fs_refs(struct path *old_root, struct path *new_root)
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{
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struct task_struct *g, *p;
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struct fs_struct *fs;
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int count = 0;
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read_lock(&tasklist_lock);
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do_each_thread(g, p) {
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task_lock(p);
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fs = p->fs;
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if (fs) {
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int hits = 0;
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spin_lock(&fs->lock);
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write_seqcount_begin(&fs->seq);
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hits += replace_path(&fs->root, old_root, new_root);
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hits += replace_path(&fs->pwd, old_root, new_root);
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write_seqcount_end(&fs->seq);
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while (hits--) {
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count++;
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path_get_longterm(new_root);
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}
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spin_unlock(&fs->lock);
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}
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task_unlock(p);
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} while_each_thread(g, p);
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read_unlock(&tasklist_lock);
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while (count--)
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path_put_longterm(old_root);
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}
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void free_fs_struct(struct fs_struct *fs)
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{
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path_put_longterm(&fs->root);
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path_put_longterm(&fs->pwd);
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kmem_cache_free(fs_cachep, fs);
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}
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void exit_fs(struct task_struct *tsk)
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{
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struct fs_struct *fs = tsk->fs;
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if (fs) {
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int kill;
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task_lock(tsk);
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spin_lock(&fs->lock);
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tsk->fs = NULL;
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kill = !--fs->users;
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spin_unlock(&fs->lock);
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task_unlock(tsk);
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if (kill)
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free_fs_struct(fs);
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}
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}
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struct fs_struct *copy_fs_struct(struct fs_struct *old)
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{
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struct fs_struct *fs = kmem_cache_alloc(fs_cachep, GFP_KERNEL);
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/* We don't need to lock fs - think why ;-) */
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if (fs) {
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fs->users = 1;
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fs->in_exec = 0;
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spin_lock_init(&fs->lock);
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seqcount_init(&fs->seq);
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fs->umask = old->umask;
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spin_lock(&old->lock);
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fs->root = old->root;
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path_get_longterm(&fs->root);
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fs->pwd = old->pwd;
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path_get_longterm(&fs->pwd);
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spin_unlock(&old->lock);
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}
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return fs;
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}
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int unshare_fs_struct(void)
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{
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struct fs_struct *fs = current->fs;
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struct fs_struct *new_fs = copy_fs_struct(fs);
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int kill;
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if (!new_fs)
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return -ENOMEM;
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task_lock(current);
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spin_lock(&fs->lock);
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kill = !--fs->users;
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current->fs = new_fs;
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spin_unlock(&fs->lock);
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task_unlock(current);
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if (kill)
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free_fs_struct(fs);
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return 0;
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}
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EXPORT_SYMBOL_GPL(unshare_fs_struct);
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int current_umask(void)
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{
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return current->fs->umask;
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}
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EXPORT_SYMBOL(current_umask);
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/* to be mentioned only in INIT_TASK */
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struct fs_struct init_fs = {
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.users = 1,
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.lock = __SPIN_LOCK_UNLOCKED(init_fs.lock),
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.seq = SEQCNT_ZERO,
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.umask = 0022,
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};
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void daemonize_fs_struct(void)
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{
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struct fs_struct *fs = current->fs;
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if (fs) {
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int kill;
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task_lock(current);
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spin_lock(&init_fs.lock);
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init_fs.users++;
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spin_unlock(&init_fs.lock);
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spin_lock(&fs->lock);
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current->fs = &init_fs;
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kill = !--fs->users;
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spin_unlock(&fs->lock);
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task_unlock(current);
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if (kill)
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free_fs_struct(fs);
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}
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}
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