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author | Karel Zak | 2011-06-23 16:06:27 +0200 |
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committer | Karel Zak | 2011-06-23 16:06:27 +0200 |
commit | 2576b4e7821339f79bc25660f86291b55c0c6486 (patch) | |
tree | 98ce8e58f7eabc379a811df968d4a3a9b3e55ab4 /libmount/src/cache.c | |
parent | libmount: cleanup return codes in mount sample (diff) | |
download | kernel-qcow2-util-linux-2576b4e7821339f79bc25660f86291b55c0c6486.tar.gz kernel-qcow2-util-linux-2576b4e7821339f79bc25660f86291b55c0c6486.tar.xz kernel-qcow2-util-linux-2576b4e7821339f79bc25660f86291b55c0c6486.zip |
libmount: allow to convert /dev/loopN to backing filename
Signed-off-by: Karel Zak <kzak@redhat.com>
Diffstat (limited to 'libmount/src/cache.c')
-rw-r--r-- | libmount/src/cache.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/libmount/src/cache.c b/libmount/src/cache.c index 2738eee80..e3bdcd089 100644 --- a/libmount/src/cache.c +++ b/libmount/src/cache.c @@ -27,6 +27,7 @@ #include "canonicalize.h" #include "mountP.h" +#include "loopdev.h" /* * Canonicalized (resolved) paths & tags cache @@ -447,6 +448,10 @@ char *mnt_get_fstype(const char *devname, int *ambi, struct libmnt_cache *cache) * @path: "native" path * @cache: cache for results or NULL * + * Converts path: + * - to the absolute path + * - /dev/dm-N to /dev/mapper/<name> + * * Returns: absolute path or NULL in case of error. The result has to be * deallocated by free() if @cache is NULL. */ @@ -490,6 +495,52 @@ error: } /** + * mnt_pretty_path: + * @path: any path + * @cache: NULL or pointer to the cache + * + * Converts path: + * - to the absolute path + * - /dev/dm-N to /dev/mapper/<name> + * - /dev/loopN to the loop backing filename + * - empty path (NULL) to 'none' + * + * Returns: new allocated string with path, result has to be always deallocated + * by free(). + */ +char *mnt_pretty_path(const char *path, struct libmnt_cache *cache) +{ + char *pretty = mnt_resolve_path(path, cache); + + if (!pretty) + return strdup("none"); + + /* users assume backing file name rather than /dev/loopN in + * output if the device has been initialized by mount(8). + */ + if (strncmp(pretty, "/dev/loop", 9) == 0) { + struct loopdev_cxt lc; + + loopcxt_init(&lc, 0); + loopcxt_set_device(&lc, pretty); + + if (loopcxt_is_autoclear(&lc)) { + char *tmp = loopcxt_get_backing_file(&lc); + if (tmp) { + if (!cache) + free(pretty); /* not cached, deallocate */ + return tmp; /* return backing file */ + } + } + loopcxt_deinit(&lc); + + } + + /* don't return pointer to the cache, allocate a new string */ + return cache ? strdup(pretty) : pretty; +} + +/** * mnt_resolve_tag: * @token: tag name * @value: tag value |