diff options
Diffstat (limited to 'tmpfs/dir.c')
| -rw-r--r-- | tmpfs/dir.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/tmpfs/dir.c b/tmpfs/dir.c new file mode 100644 index 00000000..595e5437 --- /dev/null +++ b/tmpfs/dir.c @@ -0,0 +1,239 @@ +/* Directories for tmpfs. + Copyright (C) 2000 Free Software Foundation, Inc. + +This file is part of the GNU Hurd. + +The GNU Hurd 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, or (at your option) +any later version. + +The GNU Hurd 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 the GNU Hurd; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include "tmpfs.h" +#include <stdlib.h> + +error_t +diskfs_init_dir (struct node *dp, struct node *pdp, struct protid *cred) +{ + dp->dn->u.dir.dotdot = pdp->dn; + dp->dn->u.dir.entries = 0; + return 0; +} + +error_t +diskfs_clear_directory (struct node *dp, struct node *pdp, + struct protid *cred) +{ + if (dp->dn->u.dir.entries != 0) + return ENOTEMPTY; + assert (dp->dn_stat.st_size == 0); + assert (dp->dn->u.dir.dotdot == pdp->dn); + return 0; +} + +int +diskfs_dirempty (struct node *dp, struct protid *cred) +{ + return dp->dn->u.dir.entries == 0; +} + +error_t +diskfs_get_directs (struct node *dp, int entry, int n, + char **data, u_int *datacnt, + vm_size_t bufsiz, int *amt) +{ + struct tmpfs_dirent *d; + struct dirent *entp; + int i; + + assert (offsetof (struct tmpfs_dirent, name) + >= offsetof (struct dirent, d_name)); + + if (bufsiz == 0) + bufsiz = dp->dn_stat.st_size; + if (bufsiz > *datacnt) + { + *data = mmap (0, bufsiz, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0); + if (*data == MAP_FAILED) + return ENOMEM; + } + + entp = *data; + entp->d_fileno = dp->dn_stat.st_ino; + entp->d_type = DT_DIR; + entp->d_namlen = 1; + entp->d_name[0] = '.'; + entp->d_name[1] = '\0'; + entp->d_reclen = (&entp->d_name[2] - (char *) entp + 7) & ~7; + entp = (void *) entp + entp->d_reclen; + entp->d_fileno = (ino_t) dp->dn->u.dir.dotdot; + entp->d_type = DT_DIR; + entp->d_namlen = 2; + entp->d_name[0] = '.'; + entp->d_name[1] = '.'; + entp->d_name[2] = '\0'; + entp->d_reclen = (&entp->d_name[3] - (char *) entp + 7) & ~7; + entp = (void *) entp + entp->d_reclen; + + d = dp->dn->u.dir.entries; + for (i = 2; i < entry && d != 0; ++i) + d = d->next; + + for (i = 2; d != 0; d = d->next) + { + if ((char *) entp - *data >= bufsiz || (n >= 0 && ++i > n)) + break; + entp->d_fileno = (ino_t) d->dn; + entp->d_type = DT_UNKNOWN; + entp->d_namlen = d->namelen; + memcpy (entp->d_name, d->name, d->namelen + 1); + entp->d_reclen = ((&entp->d_name[d->namelen + 1] - (char *) entp + 7) + & ~7); + entp = (void *) entp + entp->d_reclen; + } + + *datacnt = (char *) entp - *data; + *amt = i; + + return 0; +} + + +struct dirstat +{ + struct tmpfs_dirent **prevp; +}; +const size_t diskfs_dirstat_size = sizeof (struct dirstat); + +void +diskfs_null_dirstat (struct dirstat *ds) +{ + ds->prevp = 0; +} + +error_t +diskfs_drop_dirstat (struct node *dp, struct dirstat *ds) +{ + /* No need to clear the pointers. */ + return 0; +} + +error_t +diskfs_lookup_hard (struct node *dp, + const char *name, enum lookup_type type, + struct node **np, struct dirstat *ds, + struct protid *cred) +{ + const size_t namelen = strlen (name); + struct tmpfs_dirent *d, **prevp; + + if (namelen == 1 && name[0] == '.') + { + if (np != 0) + { + *np = dp; + diskfs_nref (dp); + } + return 0; + } + if (namelen == 2 && name[0] == '.' && name[1] == '.') + { + struct disknode *ddnp = dp->dn->dir.dotdot; + assert (np != 0); + if (ddnp == 0) /* root directory */ + return EAGAIN; + switch (type) + { + case LOOKUP|SPEC_DOTDOT: + diskfs_nput (dp); + default: + diskfs_nref (ddnp); + mutex_lock (&ddnp->lock); + case REMOVE|SPEC_DOTDOT: + case RENAME|SPEC_DOTDOT: + *np = ddnp; + } + return 0; + } + + for (d = *(prevp = &dp->dn->u.dir.entries); d != 0; + d = *(prevp = &d->next)) + if (d->namelen == namelen && !memcmp (d->name, name, namelen)) + { + ds->prevp = prevp; + return diskfs_cached_lookup ((ino_t) d->dn, np); + } + + ds->prevp = prevp; + return ENOENT; +} + + +error_t +diskfs_direnter_hard (struct node *dp, const char *name, + struct node *np, struct dirstat *ds, + struct protid *cred) +{ + const size_t namelen = strlen (name); + const size_t entsize = offsetof (struct tmpfs_dirent, name) + namelen + 1; + struct tmpfs_dirent *new; + + if (round_page (tmpfs_space_used + entsize) > tmpfs_page_limit) + return ENOSPC; + + new = malloc (entsize); + if (new == 0) + return ENOSPC; + + new->next = 0; + new->dn = np->dn; + new->namelen = namelen; + memcpy (new->name, name, namelen + 1); + *ds->prevp = new; + + dp->dn_stat.st_size += entsize; + adjust_used (entsize); + + dp->dn_stat.st_blocks = ((sizeof *dp->dn + dp->dn->translen + + dp->dn_stat.st_size + 511) + / 512); + return 0; +} + +error_t +diskfs_dirrewrite_hard (struct node *dp, struct node *np, + struct dirstat *ds) +{ + (*ds->prevp)->dn = np->dn; + return 0; +} + +error_t +diskfs_dirremove_hard (struct node *dp, struct dirstat *ds) +{ + struct tmpfs_dirent *d = *ds->prevp; + const size_t entsize = &d->name[d->namelen + 1] - (char *) d; + + *ds->prevp = d->next; + + if (dp->dirmod_reqs != 0) + diskfs_notice_dirchange (dp, DIR_CHANGED_UNLINK, d->name); + + free (d); + + adjust_used (-entsize); + dp->dn_stat.st_size -= entsize; + dp->dn_stat.st_blocks = ((sizeof *dp->dn + dp->dn->translen + + dp->dn_stat.st_size + 511) + / 512); + + return 0; +} |