diff options
| -rw-r--r-- | libdiskfs/lookup.c | 155 |
1 files changed, 92 insertions, 63 deletions
diff --git a/libdiskfs/lookup.c b/libdiskfs/lookup.c index 96cce94e..7c1c7133 100644 --- a/libdiskfs/lookup.c +++ b/libdiskfs/lookup.c @@ -1,5 +1,5 @@ /* Wrapper for diskfs_lookup_hard - Copyright (C) 1996 Free Software Foundation, Inc. + Copyright (C) 1996, 1997 Free Software Foundation, Inc. Written by Michael I. Bushnell, p/BSG. This file is part of the GNU Hurd. @@ -66,6 +66,10 @@ static spin_lock_t cm_lock = SPIN_LOCK_INITIALIZER; locked, so don't lock it or add a reference to it. (SPEC_DOTDOT will not be given with CREATE.) + DEPTH is the number of nodes between DP and the filesystem root. + If NEW_DEPTH is non-zero, then for a non-error return, the depth of the + resulting node NP is returned in it. + Return ENOTDIR if DP is not a directory. Return EACCES if CRED isn't allowed to search DP. Return EACCES if completing the operation will require writing @@ -79,9 +83,10 @@ static spin_lock_t cm_lock = SPIN_LOCK_INITIALIZER; error_t diskfs_lookup (struct node *dp, char *name, enum lookup_type type, struct node **np, struct dirstat *ds, - struct protid *cred) + struct protid *cred, unsigned depth, unsigned *new_depth) { error_t err; + struct node *cached; if (type == REMOVE || type == RENAME) assert (np); @@ -92,6 +97,7 @@ diskfs_lookup (struct node *dp, char *name, enum lookup_type type, diskfs_null_dirstat (ds); return ENOTDIR; } + err = fshelp_access (&dp->dn_stat, S_IEXEC, cred->user); if (err) { @@ -100,79 +106,102 @@ diskfs_lookup (struct node *dp, char *name, enum lookup_type type, return err; } - if (type == LOOKUP) + if (depth == 0 && name[0] == '.' && name[1] == '.' && name[2] == '\0') + /* Ran into the root. */ { - /* Check the cache first */ - struct node *cached = diskfs_check_lookup_cache (dp, name); - - if (cached == (struct node *)-1) - /* Negative lookup cached. */ - { - if (np) - *np = 0; - return ENOENT; - } - else if (cached) - { - if (np) - *np = cached; /* Return what we found. */ - else - /* Ick, the user doesn't want the result, we have to drop our - reference. */ - if (cached == dp) - diskfs_nrele (cached); - else - diskfs_nput (cached); - if (ds) - diskfs_null_dirstat (ds); - return 0; - } + if (ds) + diskfs_null_dirstat (ds); + return EAGAIN; } - - err = diskfs_lookup_hard (dp, name, type, np, ds, cred); - spin_lock (&cm_lock); if (type == LOOKUP) + /* Check the cache first */ + cached = diskfs_check_lookup_cache (dp, name); + else + cached = 0; + + if (cached == (struct node *)-1) + /* Negative lookup cached. */ + { + if (np) + *np = 0; + return ENOENT; + } + else if (cached) { - if (err == ENOENT) - cache_misses.absent++; - else if (err) - cache_misses.errors++; - else - cache_misses.present++; - if (name[0] == '.') + if (np) + *np = cached; /* Return what we found. */ + else + /* Ick, the user doesn't want the result, we have to drop our + reference. */ + if (cached == dp) + diskfs_nrele (cached); + else + diskfs_nput (cached); + + if (ds) + diskfs_null_dirstat (ds); + } + else + { + err = diskfs_lookup_hard (dp, name, type, np, ds, cred); + assert (err != EAGAIN); /* We should never get EAGAIN now that we're + detecting the root ourselves. */ + + spin_lock (&cm_lock); + if (type == LOOKUP) { - if (name[1] == '\0') - cache_misses.dot++; - else if (name[1] == '.' && name[2] == '\0') - cache_misses.dotdot++; + if (err == ENOENT) + cache_misses.absent++; + else if (err) + cache_misses.errors++; + else + cache_misses.present++; + if (name[0] == '.') + { + if (name[1] == '\0') + cache_misses.dot++; + else if (name[1] == '.' && name[2] == '\0') + cache_misses.dotdot++; + } } - } - spin_unlock (&cm_lock); + spin_unlock (&cm_lock); - if (err && err != ENOENT) - return err; + if (err && err != ENOENT) + return err; - if (type == RENAME - || (type == CREATE && err == ENOENT) - || (type == REMOVE && err != ENOENT)) - { - error_t err2 = fshelp_checkdirmod (&dp->dn_stat, - (err || !np) ? 0 : &(*np)->dn_stat, - cred->user); - if (err2) + if (type == RENAME + || (type == CREATE && err == ENOENT) + || (type == REMOVE && err != ENOENT)) { - if (np && !err) - diskfs_nput (*np); - return err2; + error_t err2 = fshelp_checkdirmod (&dp->dn_stat, + (err || !np) ? 0 : &(*np)->dn_stat, + cred->user); + if (err2) + { + if (np && !err) + diskfs_nput (*np); + return err2; + } } - } - if ((type == LOOKUP || type == CREATE) && !err && np) - diskfs_enter_lookup_cache (dp, *np, name); - else if (type == LOOKUP && err == ENOENT) - diskfs_enter_lookup_cache (dp, 0, name); - + if ((type == LOOKUP || type == CREATE) && !err && np) + diskfs_enter_lookup_cache (dp, *np, name); + else if (type == LOOKUP && err == ENOENT) + diskfs_enter_lookup_cache (dp, 0, name); + } + + if (!err && new_depth) + if (name[0] == '.') + if (name[1] == '\0') + *new_depth = depth; + else if (name[1] == '.' && name[2] == '\0') + *new_depth = depth - 1; + else + *new_depth = depth + 1; + else + *new_depth = depth + 1; + return err; } |