diff options
Diffstat (limited to 'fs/aufs/dir.c')
| -rw-r--r-- | fs/aufs/dir.c | 753 |
1 files changed, 753 insertions, 0 deletions
diff --git a/fs/aufs/dir.c b/fs/aufs/dir.c new file mode 100644 index 000000000..7705c2997 --- /dev/null +++ b/fs/aufs/dir.c @@ -0,0 +1,753 @@ +/* + * Copyright (C) 2005-2015 Junjiro R. Okajima + * + * This program, aufs is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +/* + * directory operations + */ + +#include <linux/fs_stack.h> +#include "aufs.h" + +void au_add_nlink(struct inode *dir, struct inode *h_dir) +{ + unsigned int nlink; + + AuDebugOn(!S_ISDIR(dir->i_mode) || !S_ISDIR(h_dir->i_mode)); + + nlink = dir->i_nlink; + nlink += h_dir->i_nlink - 2; + if (h_dir->i_nlink < 2) + nlink += 2; + smp_mb(); /* for i_nlink */ + /* 0 can happen in revaliding */ + set_nlink(dir, nlink); +} + +void au_sub_nlink(struct inode *dir, struct inode *h_dir) +{ + unsigned int nlink; + + AuDebugOn(!S_ISDIR(dir->i_mode) || !S_ISDIR(h_dir->i_mode)); + + nlink = dir->i_nlink; + nlink -= h_dir->i_nlink - 2; + if (h_dir->i_nlink < 2) + nlink -= 2; + smp_mb(); /* for i_nlink */ + /* nlink == 0 means the branch-fs is broken */ + set_nlink(dir, nlink); +} + +loff_t au_dir_size(struct file *file, struct dentry *dentry) +{ + loff_t sz; + aufs_bindex_t bindex, bend; + struct file *h_file; + struct dentry *h_dentry; + + sz = 0; + if (file) { + AuDebugOn(!d_is_dir(file->f_path.dentry)); + + bend = au_fbend_dir(file); + for (bindex = au_fbstart(file); + bindex <= bend && sz < KMALLOC_MAX_SIZE; + bindex++) { + h_file = au_hf_dir(file, bindex); + if (h_file && file_inode(h_file)) + sz += vfsub_f_size_read(h_file); + } + } else { + AuDebugOn(!dentry); + AuDebugOn(!d_is_dir(dentry)); + + bend = au_dbtaildir(dentry); + for (bindex = au_dbstart(dentry); + bindex <= bend && sz < KMALLOC_MAX_SIZE; + bindex++) { + h_dentry = au_h_dptr(dentry, bindex); + if (h_dentry && d_is_positive(h_dentry)) + sz += i_size_read(d_inode(h_dentry)); + } + } + if (sz < KMALLOC_MAX_SIZE) + sz = roundup_pow_of_two(sz); + if (sz > KMALLOC_MAX_SIZE) + sz = KMALLOC_MAX_SIZE; + else if (sz < NAME_MAX) { + BUILD_BUG_ON(AUFS_RDBLK_DEF < NAME_MAX); + sz = AUFS_RDBLK_DEF; + } + return sz; +} + +struct au_dir_ts_arg { + struct dentry *dentry; + aufs_bindex_t brid; +}; + +static void au_do_dir_ts(void *arg) +{ + struct au_dir_ts_arg *a = arg; + struct au_dtime dt; + struct path h_path; + struct inode *dir, *h_dir; + struct super_block *sb; + struct au_branch *br; + struct au_hinode *hdir; + int err; + aufs_bindex_t bstart, bindex; + + sb = a->dentry->d_sb; + if (d_really_is_negative(a->dentry)) + goto out; + aufs_read_lock(a->dentry, AuLock_DW | AuLock_DIR); /* noflush */ + + /* no dir->i_mutex lock */ + dir = d_inode(a->dentry); + bstart = au_ibstart(dir); + bindex = au_br_index(sb, a->brid); + if (bindex < bstart) + goto out_unlock; + + br = au_sbr(sb, bindex); + h_path.dentry = au_h_dptr(a->dentry, bindex); + if (!h_path.dentry) + goto out_unlock; + h_path.mnt = au_br_mnt(br); + au_dtime_store(&dt, a->dentry, &h_path); + + br = au_sbr(sb, bstart); + if (!au_br_writable(br->br_perm)) + goto out_unlock; + h_path.dentry = au_h_dptr(a->dentry, bstart); + h_path.mnt = au_br_mnt(br); + err = vfsub_mnt_want_write(h_path.mnt); + if (err) + goto out_unlock; + hdir = au_hi(dir, bstart); + au_hn_imtx_lock_nested(hdir, AuLsc_I_PARENT); + h_dir = au_h_iptr(dir, bstart); + if (h_dir->i_nlink + && timespec_compare(&h_dir->i_mtime, &dt.dt_mtime) < 0) { + dt.dt_h_path = h_path; + au_dtime_revert(&dt); + } + au_hn_imtx_unlock(hdir); + vfsub_mnt_drop_write(h_path.mnt); + au_cpup_attr_timesizes(dir); + +out_unlock: + aufs_read_unlock(a->dentry, AuLock_DW); +out: + dput(a->dentry); + au_nwt_done(&au_sbi(sb)->si_nowait); + kfree(arg); +} + +void au_dir_ts(struct inode *dir, aufs_bindex_t bindex) +{ + int perm, wkq_err; + aufs_bindex_t bstart; + struct au_dir_ts_arg *arg; + struct dentry *dentry; + struct super_block *sb; + + IMustLock(dir); + + dentry = d_find_any_alias(dir); + AuDebugOn(!dentry); + sb = dentry->d_sb; + bstart = au_ibstart(dir); + if (bstart == bindex) { + au_cpup_attr_timesizes(dir); + goto out; + } + + perm = au_sbr_perm(sb, bstart); + if (!au_br_writable(perm)) + goto out; + + arg = kmalloc(sizeof(*arg), GFP_NOFS); + if (!arg) + goto out; + + arg->dentry = dget(dentry); /* will be dput-ted by au_do_dir_ts() */ + arg->brid = au_sbr_id(sb, bindex); + wkq_err = au_wkq_nowait(au_do_dir_ts, arg, sb, /*flags*/0); + if (unlikely(wkq_err)) { + pr_err("wkq %d\n", wkq_err); + dput(dentry); + kfree(arg); + } + +out: + dput(dentry); +} + +/* ---------------------------------------------------------------------- */ + +static int reopen_dir(struct file *file) +{ + int err; + unsigned int flags; + aufs_bindex_t bindex, btail, bstart; + struct dentry *dentry, *h_dentry; + struct file *h_file; + + /* open all lower dirs */ + dentry = file->f_path.dentry; + bstart = au_dbstart(dentry); + for (bindex = au_fbstart(file); bindex < bstart; bindex++) + au_set_h_fptr(file, bindex, NULL); + au_set_fbstart(file, bstart); + + btail = au_dbtaildir(dentry); + for (bindex = au_fbend_dir(file); btail < bindex; bindex--) + au_set_h_fptr(file, bindex, NULL); + au_set_fbend_dir(file, btail); + + flags = vfsub_file_flags(file); + for (bindex = bstart; bindex <= btail; bindex++) { + h_dentry = au_h_dptr(dentry, bindex); + if (!h_dentry) + continue; + h_file = au_hf_dir(file, bindex); + if (h_file) + continue; + + h_file = au_h_open(dentry, bindex, flags, file, /*force_wr*/0); + err = PTR_ERR(h_file); + if (IS_ERR(h_file)) + goto out; /* close all? */ + au_set_h_fptr(file, bindex, h_file); + } + au_update_figen(file); + /* todo: necessary? */ + /* file->f_ra = h_file->f_ra; */ + err = 0; + +out: + return err; +} + +static int do_open_dir(struct file *file, int flags, struct file *h_file) +{ + int err; + aufs_bindex_t bindex, btail; + struct dentry *dentry, *h_dentry; + + FiMustWriteLock(file); + AuDebugOn(h_file); + + err = 0; + dentry = file->f_path.dentry; + file->f_version = d_inode(dentry)->i_version; + bindex = au_dbstart(dentry); + au_set_fbstart(file, bindex); + btail = au_dbtaildir(dentry); + au_set_fbend_dir(file, btail); + for (; !err && bindex <= btail; bindex++) { + h_dentry = au_h_dptr(dentry, bindex); + if (!h_dentry) + continue; + + h_file = au_h_open(dentry, bindex, flags, file, /*force_wr*/0); + if (IS_ERR(h_file)) { + err = PTR_ERR(h_file); + break; + } + au_set_h_fptr(file, bindex, h_file); + } + au_update_figen(file); + /* todo: necessary? */ + /* file->f_ra = h_file->f_ra; */ + if (!err) + return 0; /* success */ + + /* close all */ + for (bindex = au_fbstart(file); bindex <= btail; bindex++) + au_set_h_fptr(file, bindex, NULL); + au_set_fbstart(file, -1); + au_set_fbend_dir(file, -1); + + return err; +} + +static int aufs_open_dir(struct inode *inode __maybe_unused, + struct file *file) +{ + int err; + struct super_block *sb; + struct au_fidir *fidir; + + err = -ENOMEM; + sb = file->f_path.dentry->d_sb; + si_read_lock(sb, AuLock_FLUSH); + fidir = au_fidir_alloc(sb); + if (fidir) { + struct au_do_open_args args = { + .open = do_open_dir, + .fidir = fidir + }; + err = au_do_open(file, &args); + if (unlikely(err)) + kfree(fidir); + } + si_read_unlock(sb); + return err; +} + +static int aufs_release_dir(struct inode *inode __maybe_unused, + struct file *file) +{ + struct au_vdir *vdir_cache; + struct au_finfo *finfo; + struct au_fidir *fidir; + aufs_bindex_t bindex, bend; + + finfo = au_fi(file); + fidir = finfo->fi_hdir; + if (fidir) { + au_sphl_del(&finfo->fi_hlist, + &au_sbi(file->f_path.dentry->d_sb)->si_files); + vdir_cache = fidir->fd_vdir_cache; /* lock-free */ + if (vdir_cache) + au_vdir_free(vdir_cache); + + bindex = finfo->fi_btop; + if (bindex >= 0) { + /* + * calls fput() instead of filp_close(), + * since no dnotify or lock for the lower file. + */ + bend = fidir->fd_bbot; + for (; bindex <= bend; bindex++) + au_set_h_fptr(file, bindex, NULL); + } + kfree(fidir); + finfo->fi_hdir = NULL; + } + au_finfo_fin(file); + return 0; +} + +/* ---------------------------------------------------------------------- */ + +static int au_do_flush_dir(struct file *file, fl_owner_t id) +{ + int err; + aufs_bindex_t bindex, bend; + struct file *h_file; + + err = 0; + bend = au_fbend_dir(file); + for (bindex = au_fbstart(file); !err && bindex <= bend; bindex++) { + h_file = au_hf_dir(file, bindex); + if (h_file) + err = vfsub_flush(h_file, id); + } + return err; +} + +static int aufs_flush_dir(struct file *file, fl_owner_t id) +{ + return au_do_flush(file, id, au_do_flush_dir); +} + +/* ---------------------------------------------------------------------- */ + +static int au_do_fsync_dir_no_file(struct dentry *dentry, int datasync) +{ + int err; + aufs_bindex_t bend, bindex; + struct inode *inode; + struct super_block *sb; + + err = 0; + sb = dentry->d_sb; + inode = d_inode(dentry); + IMustLock(inode); + bend = au_dbend(dentry); + for (bindex = au_dbstart(dentry); !err && bindex <= bend; bindex++) { + struct path h_path; + + if (au_test_ro(sb, bindex, inode)) + continue; + h_path.dentry = au_h_dptr(dentry, bindex); + if (!h_path.dentry) + continue; + + h_path.mnt = au_sbr_mnt(sb, bindex); + err = vfsub_fsync(NULL, &h_path, datasync); + } + + return err; +} + +static int au_do_fsync_dir(struct file *file, int datasync) +{ + int err; + aufs_bindex_t bend, bindex; + struct file *h_file; + struct super_block *sb; + struct inode *inode; + + err = au_reval_and_lock_fdi(file, reopen_dir, /*wlock*/1); + if (unlikely(err)) + goto out; + + inode = file_inode(file); + sb = inode->i_sb; + bend = au_fbend_dir(file); + for (bindex = au_fbstart(file); !err && bindex <= bend; bindex++) { + h_file = au_hf_dir(file, bindex); + if (!h_file || au_test_ro(sb, bindex, inode)) + continue; + + err = vfsub_fsync(h_file, &h_file->f_path, datasync); + } + +out: + return err; +} + +/* + * @file may be NULL + */ +static int aufs_fsync_dir(struct file *file, loff_t start, loff_t end, + int datasync) +{ + int err; + struct dentry *dentry; + struct inode *inode; + struct super_block *sb; + struct mutex *mtx; + + err = 0; + dentry = file->f_path.dentry; + inode = d_inode(dentry); + mtx = &inode->i_mutex; + mutex_lock(mtx); + sb = dentry->d_sb; + si_noflush_read_lock(sb); + if (file) + err = au_do_fsync_dir(file, datasync); + else { + di_write_lock_child(dentry); + err = au_do_fsync_dir_no_file(dentry, datasync); + } + au_cpup_attr_timesizes(inode); + di_write_unlock(dentry); + if (file) + fi_write_unlock(file); + + si_read_unlock(sb); + mutex_unlock(mtx); + return err; +} + +/* ---------------------------------------------------------------------- */ + +static int aufs_iterate(struct file *file, struct dir_context *ctx) +{ + int err; + struct dentry *dentry; + struct inode *inode, *h_inode; + struct super_block *sb; + + AuDbg("%pD, ctx{%pf, %llu}\n", file, ctx->actor, ctx->pos); + + dentry = file->f_path.dentry; + inode = d_inode(dentry); + IMustLock(inode); + + sb = dentry->d_sb; + si_read_lock(sb, AuLock_FLUSH); + err = au_reval_and_lock_fdi(file, reopen_dir, /*wlock*/1); + if (unlikely(err)) + goto out; + err = au_alive_dir(dentry); + if (!err) + err = au_vdir_init(file); + di_downgrade_lock(dentry, AuLock_IR); + if (unlikely(err)) + goto out_unlock; + + h_inode = au_h_iptr(inode, au_ibstart(inode)); + if (!au_test_nfsd()) { + err = au_vdir_fill_de(file, ctx); + fsstack_copy_attr_atime(inode, h_inode); + } else { + /* + * nfsd filldir may call lookup_one_len(), vfs_getattr(), + * encode_fh() and others. + */ + atomic_inc(&h_inode->i_count); + di_read_unlock(dentry, AuLock_IR); + si_read_unlock(sb); + err = au_vdir_fill_de(file, ctx); + fsstack_copy_attr_atime(inode, h_inode); + fi_write_unlock(file); + iput(h_inode); + + AuTraceErr(err); + return err; + } + +out_unlock: + di_read_unlock(dentry, AuLock_IR); + fi_write_unlock(file); +out: + si_read_unlock(sb); + return err; +} + +/* ---------------------------------------------------------------------- */ + +#define AuTestEmpty_WHONLY 1 +#define AuTestEmpty_CALLED (1 << 1) +#define AuTestEmpty_SHWH (1 << 2) +#define au_ftest_testempty(flags, name) ((flags) & AuTestEmpty_##name) +#define au_fset_testempty(flags, name) \ + do { (flags) |= AuTestEmpty_##name; } while (0) +#define au_fclr_testempty(flags, name) \ + do { (flags) &= ~AuTestEmpty_##name; } while (0) + +#ifndef CONFIG_AUFS_SHWH +#undef AuTestEmpty_SHWH +#define AuTestEmpty_SHWH 0 +#endif + +struct test_empty_arg { + struct dir_context ctx; + struct au_nhash *whlist; + unsigned int flags; + int err; + aufs_bindex_t bindex; +}; + +static int test_empty_cb(struct dir_context *ctx, const char *__name, + int namelen, loff_t offset __maybe_unused, u64 ino, + unsigned int d_type) +{ + struct test_empty_arg *arg = container_of(ctx, struct test_empty_arg, + ctx); + char *name = (void *)__name; + + arg->err = 0; + au_fset_testempty(arg->flags, CALLED); + /* smp_mb(); */ + if (name[0] == '.' + && (namelen == 1 || (name[1] == '.' && namelen == 2))) + goto out; /* success */ + + if (namelen <= AUFS_WH_PFX_LEN + || memcmp(name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) { + if (au_ftest_testempty(arg->flags, WHONLY) + && !au_nhash_test_known_wh(arg->whlist, name, namelen)) + arg->err = -ENOTEMPTY; + goto out; + } + + name += AUFS_WH_PFX_LEN; + namelen -= AUFS_WH_PFX_LEN; + if (!au_nhash_test_known_wh(arg->whlist, name, namelen)) + arg->err = au_nhash_append_wh + (arg->whlist, name, namelen, ino, d_type, arg->bindex, + au_ftest_testempty(arg->flags, SHWH)); + +out: + /* smp_mb(); */ + AuTraceErr(arg->err); + return arg->err; +} + +static int do_test_empty(struct dentry *dentry, struct test_empty_arg *arg) +{ + int err; + struct file *h_file; + + h_file = au_h_open(dentry, arg->bindex, + O_RDONLY | O_NONBLOCK | O_DIRECTORY | O_LARGEFILE, + /*file*/NULL, /*force_wr*/0); + err = PTR_ERR(h_file); + if (IS_ERR(h_file)) + goto out; + + err = 0; + if (!au_opt_test(au_mntflags(dentry->d_sb), UDBA_NONE) + && !file_inode(h_file)->i_nlink) + goto out_put; + + do { + arg->err = 0; + au_fclr_testempty(arg->flags, CALLED); + /* smp_mb(); */ + err = vfsub_iterate_dir(h_file, &arg->ctx); + if (err >= 0) + err = arg->err; + } while (!err && au_ftest_testempty(arg->flags, CALLED)); + +out_put: + fput(h_file); + au_sbr_put(dentry->d_sb, arg->bindex); +out: + return err; +} + +struct do_test_empty_args { + int *errp; + struct dentry *dentry; + struct test_empty_arg *arg; +}; + +static void call_do_test_empty(void *args) +{ + struct do_test_empty_args *a = args; + *a->errp = do_test_empty(a->dentry, a->arg); +} + +static int sio_test_empty(struct dentry *dentry, struct test_empty_arg *arg) +{ + int err, wkq_err; + struct dentry *h_dentry; + struct inode *h_inode; + + h_dentry = au_h_dptr(dentry, arg->bindex); + h_inode = d_inode(h_dentry); + /* todo: i_mode changes anytime? */ + mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD); + err = au_test_h_perm_sio(h_inode, MAY_EXEC | MAY_READ); + mutex_unlock(&h_inode->i_mutex); + if (!err) + err = do_test_empty(dentry, arg); + else { + struct do_test_empty_args args = { + .errp = &err, + .dentry = dentry, + .arg = arg + }; + unsigned int flags = arg->flags; + + wkq_err = au_wkq_wait(call_do_test_empty, &args); + if (unlikely(wkq_err)) + err = wkq_err; + arg->flags = flags; + } + + return err; +} + +int au_test_empty_lower(struct dentry *dentry) +{ + int err; + unsigned int rdhash; + aufs_bindex_t bindex, bstart, btail; + struct au_nhash whlist; + struct test_empty_arg arg = { + .ctx = { + .actor = test_empty_cb + } + }; + int (*test_empty)(struct dentry *dentry, struct test_empty_arg *arg); + + SiMustAnyLock(dentry->d_sb); + + rdhash = au_sbi(dentry->d_sb)->si_rdhash; + if (!rdhash) + rdhash = au_rdhash_est(au_dir_size(/*file*/NULL, dentry)); + err = au_nhash_alloc(&whlist, rdhash, GFP_NOFS); + if (unlikely(err)) + goto out; + + arg.flags = 0; + arg.whlist = &whlist; + bstart = au_dbstart(dentry); + if (au_opt_test(au_mntflags(dentry->d_sb), SHWH)) + au_fset_testempty(arg.flags, SHWH); + test_empty = do_test_empty; + if (au_opt_test(au_mntflags(dentry->d_sb), DIRPERM1)) + test_empty = sio_test_empty; + arg.bindex = bstart; + err = test_empty(dentry, &arg); + if (unlikely(err)) + goto out_whlist; + + au_fset_testempty(arg.flags, WHONLY); + btail = au_dbtaildir(dentry); + for (bindex = bstart + 1; !err && bindex <= btail; bindex++) { + struct dentry *h_dentry; + + h_dentry = au_h_dptr(dentry, bindex); + if (h_dentry && d_is_positive(h_dentry)) { + arg.bindex = bindex; + err = test_empty(dentry, &arg); + } + } + +out_whlist: + au_nhash_wh_free(&whlist); +out: + return err; +} + +int au_test_empty(struct dentry *dentry, struct au_nhash *whlist) +{ + int err; + struct test_empty_arg arg = { + .ctx = { + .actor = test_empty_cb + } + }; + aufs_bindex_t bindex, btail; + + err = 0; + arg.whlist = whlist; + arg.flags = AuTestEmpty_WHONLY; + if (au_opt_test(au_mntflags(dentry->d_sb), SHWH)) + au_fset_testempty(arg.flags, SHWH); + btail = au_dbtaildir(dentry); + for (bindex = au_dbstart(dentry); !err && bindex <= btail; bindex++) { + struct dentry *h_dentry; + + h_dentry = au_h_dptr(dentry, bindex); + if (h_dentry && d_is_positive(h_dentry)) { + arg.bindex = bindex; + err = sio_test_empty(dentry, &arg); + } + } + + return err; +} + +/* ---------------------------------------------------------------------- */ + +const struct file_operations aufs_dir_fop = { + .owner = THIS_MODULE, + .llseek = default_llseek, + .read = generic_read_dir, + .iterate = aufs_iterate, + .unlocked_ioctl = aufs_ioctl_dir, +#ifdef CONFIG_COMPAT + .compat_ioctl = aufs_compat_ioctl_dir, +#endif + .open = aufs_open_dir, + .release = aufs_release_dir, + .flush = aufs_flush_dir, + .fsync = aufs_fsync_dir +}; |