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o Quick and dirty *UGLY* hack of a /proc/devices cache using a linked list

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o I don't like it, but I'm committing it so I can go back and laugh at
   myself later
 o I have a (hopefully) better idea that i'll try to commit yet today.
This commit is contained in:
AJ Lewis 2001-08-21 19:51:04 +00:00
parent 7af02225cc
commit 83b2c0d30a
1 changed files with 50 additions and 24 deletions
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74
lib/dev-mgr/dev-manager.c
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@ -73,12 +73,21 @@ struct dev_i {
struct dev_i *next; struct dev_i *next;
}; };
/* temporary structure - will replace with something smarter later */
struct dev_n {
int major;
struct dev_n *next;
};
struct dev_mgr { struct dev_mgr {
/* everything is allocated from this pool */ /* everything is allocated from this pool */
struct pool *pool; struct pool *pool;
int has_scanned; int has_scanned;
/* linked list of valid major numbers */
struct dev_n *dev_list;
/* hash table */ /* hash table */
int num_slots; int num_slots;
int mask; int mask;
@ -110,7 +119,8 @@ static void _name_insert(struct dev_mgr *dm, struct dev_i *device);
static void _dev_insert(struct dev_mgr *dm, struct dev_i *device); static void _dev_insert(struct dev_mgr *dm, struct dev_i *device);
static void _list_insert(struct dev_mgr *dm, struct dev_i *device); static void _list_insert(struct dev_mgr *dm, struct dev_i *device);
static unsigned int _hash_dev(dev_t d); static unsigned int _hash_dev(dev_t d);
static int _check_dev(struct stat *stat_b); static int _check_dev(struct dev_mgr *dm, struct stat *stat_b);
static int _scan_proc_dev(struct dev_mgr *dm);
static inline struct device *_get_dev(struct dev_i *di) static inline struct device *_get_dev(struct dev_i *di)
{ {
@ -151,6 +161,8 @@ struct dev_mgr *init_dev_manager(struct config_node *cn)
return 0; return 0;
} }
_scan_proc_dev(dm);
return dm; return dm;
} }
@ -262,7 +274,7 @@ static struct dev_i *_add_named_device(struct dev_mgr *dm, const char *devpath)
struct stat stat_b; struct stat stat_b;
/* FIXME: move lvm_check_dev into this file */ /* FIXME: move lvm_check_dev into this file */
if ((stat(devpath, &stat_b) == -1) || _check_dev(&stat_b)) if ((stat(devpath, &stat_b) == -1) || _check_dev(dm, &stat_b))
goto out; goto out;
/* Check for directories and scan them if they aren't this directory /* Check for directories and scan them if they aren't this directory
@ -425,23 +437,37 @@ static unsigned int _hash_dev(dev_t d)
return (unsigned int) d; return (unsigned int) d;
} }
static int _check_dev(struct stat *stat_b) static int _check_dev(struct dev_mgr *dm, struct stat *stat_b)
{ {
char line[80];
int ret = 1; int ret = 1;
int seek_major = MAJOR(stat_b->st_rdev); int seek_major = MAJOR(stat_b->st_rdev);
struct dev_n *node;
if (stat_b == NULL) if (stat_b == NULL)
ret = -LOCAL_EPARAM; ret = -LOCAL_EPARAM;
else if ( ! S_ISBLK(stat_b->st_mode)) else if ( ! S_ISBLK(stat_b->st_mode))
ret = -LOCAL_CHECK_NAME; ret = -LOCAL_CHECK_NAME;
else { else {
for(node = dm->dev_list; node != NULL; node = node->next)
if (node->major == seek_major)
ret = 0;
}
return ret;
}
/* Caches /proc/device info and
returns the number of block devices found in /proc/devices */
static int _scan_proc_dev(struct dev_mgr *dm)
{
char line[80];
FILE *procdevices = NULL; FILE *procdevices = NULL;
int ret = 0;
int i, j = 0; int i, j = 0;
int line_major = 0; int line_major = 0;
int blocksection = 0; int blocksection = 0;
struct dev_n * dev_node= NULL;
/* FIXME Ought to cache this first time */
if ((procdevices = fopen("/proc/devices", "r")) != NULL) { if ((procdevices = fopen("/proc/devices", "r")) != NULL) {
while (fgets(line, 80, procdevices) != NULL) { while (fgets(line, 80, procdevices) != NULL) {
i = 0; i = 0;
@ -458,34 +484,34 @@ static int _check_dev(struct stat *stat_b)
if (!blocksection) if (!blocksection)
continue; continue;
if (line_major == seek_major) { /* Find the start of the device major name */
while (line[i] != ' ' && line[i] != '\0') while (line[i] != ' ' && line[i] != '\0')
i++; i++;
while (line[i] == ' ' && line[i] != '\0') while (line[i] == ' ' && line[i] != '\0')
i++; i++;
for (j = 0; device_names[j] != NULL; j++) {
if (strlen(device_names[j]) for (j = 0; device_names[j] != NULL; j++) {
<= strlen(line + i)) { if (strlen(device_names[j])
<= strlen(line + i)) {
if (strncmp (device_names[j], if (strncmp (device_names[j],
line + i, line + i,
strlen(device_names[j])) == 0) { strlen(device_names[j])) == 0) {
ret = j; dev_node = pool_alloc(dm->pool,
break; sizeof(*dev_node));
dev_node->major = line_major;
dev_node->next=dm->dev_list;
dm->dev_list = dev_node;
ret++;
break;
} }
}
} }
break;
} }
} }
fclose(procdevices); fclose(procdevices);
} }
}
return ret; return ret;
} }
/* /*
* Local variables: * Local variables:
* c-file-style: "linux" * c-file-style: "linux"