commit ed350fc6c49155ec398866ebef1d59be02636bce Author: Eric Sandeen Date: Wed Jul 16 13:53:47 2014 +1000 libxcmd: make all comparisons using realpath'd paths Both mountpoints and devices can be symlinks, so given a path to look for, and mountpoints/devices from the system, use realpath() on *everything* before making the comparison to see if our path is a match. So, with symlinks for mount points as well as for devices: # ls -l /dev/mapper/testvg-lvol0 lrwxrwxrwx. 1 root root 7 Jul 11 19:24 /dev/mapper/testvg-lvol0 -> ../dm-3 # ls -l /mnt/scratch2 lrwxrwxrwx. 1 root root 12 Jul 11 19:57 /mnt/scratch2 -> /mnt/scratch this should all work, and does now: # xfs_quota -xc "report -h" /mnt/scratch2 User quota on /mnt/scratch (/dev/mapper/testvg-lvol0) Blocks User ID Used Soft Hard Warn/Grace ---------- --------------------------------- root 0 0 0 00 [------] # xfs_quota -xc "report -h" /mnt/scratch User quota on /mnt/scratch (/dev/mapper/testvg-lvol0) Blocks User ID Used Soft Hard Warn/Grace ---------- --------------------------------- root 0 0 0 00 [------] # xfs_quota -xc "report -h" /dev/dm-3 User quota on /mnt/scratch (/dev/mapper/testvg-lvol0) Blocks User ID Used Soft Hard Warn/Grace ---------- --------------------------------- root 0 0 0 00 [------] # xfs_quota -xc "report -h" /dev/mapper/testvg-lvol0 User quota on /mnt/scratch (/dev/mapper/testvg-lvol0) Blocks User ID Used Soft Hard Warn/Grace ---------- --------------------------------- root 0 0 0 00 [------] The commit: 050a7f1 xfsprogs: handle symlinks etc in fs_table_initialise_mounts() tried to fix this earlier, but only worked one way; it compared the argument path in both given and realpath form to the paths in getmntent, but did not compare to the realpaths of the getmntent devices. If we reduce everything, everywhere, to a realpath(), we've got our best shot at finding the match. Signed-off-by: Eric Sandeen Reviewed-by: Christoph Hellwig Signed-off-by: Dave Chinner diff --git a/libxcmd/paths.c b/libxcmd/paths.c index 7b0e434..443adbb 100644 --- a/libxcmd/paths.c +++ b/libxcmd/paths.c @@ -269,6 +269,9 @@ out_nomem: /* * If *path is NULL, initialize the fs table with all xfs mount points in mtab * If *path is specified, search for that path in mtab + * + * Everything - path, devices, and mountpoints - are boiled down to realpath() + * for comparison, but fs_table is populated with what comes from getmntent. */ static int fs_table_initialise_mounts( @@ -278,7 +281,7 @@ fs_table_initialise_mounts( FILE *mtp; char *fslog, *fsrt; int error, found; - char *rpath = NULL; + char rpath[PATH_MAX], rmnt_fsname[PATH_MAX], rmnt_dir[PATH_MAX]; error = found = 0; fslog = fsrt = NULL; @@ -294,17 +297,20 @@ fs_table_initialise_mounts( /* Use realpath to resolve symlinks, relative paths, etc */ if (path) - if ((rpath = realpath(path, NULL)) == NULL) - return ENOENT; + if (!realpath(path, rpath)) + return errno; while ((mnt = getmntent(mtp)) != NULL) { if (strcmp(mnt->mnt_type, "xfs") != 0) continue; + if (!realpath(mnt->mnt_dir, rmnt_dir)) + continue; + if (!realpath(mnt->mnt_fsname, rmnt_fsname)) + continue; + if (path && - ((strcmp(path, mnt->mnt_dir) != 0) && - (strcmp(path, mnt->mnt_fsname) != 0) && - (strcmp(rpath, mnt->mnt_dir) != 0) && - (strcmp(rpath, mnt->mnt_fsname) != 0))) + ((strcmp(rpath, rmnt_dir) != 0) && + (strcmp(rpath, rmnt_fsname) != 0))) continue; if (fs_extract_mount_options(mnt, &fslog, &fsrt)) continue; @@ -316,7 +322,6 @@ fs_table_initialise_mounts( } } endmntent(mtp); - free(rpath); if (path && !found) error = ENXIO; @@ -330,6 +335,9 @@ fs_table_initialise_mounts( /* * If *path is NULL, initialize the fs table with all xfs mount points in mtab * If *path is specified, search for that path in mtab + * + * Everything - path, devices, and mountpoints - are boiled down to realpath() + * for comparison, but fs_table is populated with what comes from getmntinfo. */ static int fs_table_initialise_mounts( @@ -337,7 +345,7 @@ fs_table_initialise_mounts( { struct statfs *stats; int i, count, error, found; - char *rpath = NULL; + char rpath[PATH_MAX], rmntfromname[PATH_MAX], rmntonname[PATH_MAX]; error = found = 0; if ((count = getmntinfo(&stats, 0)) < 0) { @@ -348,17 +356,20 @@ fs_table_initialise_mounts( /* Use realpath to resolve symlinks, relative paths, etc */ if (path) - if ((rpath = realpath(path, NULL)) == NULL) - return ENOENT; + if (!realpath(path, rpath)) + return errno; for (i = 0; i < count; i++) { if (strcmp(stats[i].f_fstypename, "xfs") != 0) continue; + if (!realpath(stats[i].f_mntfromname, rmntfromname)) + continue; + if (!realpath(stats[i].f_mntonname, rmnttomname))) + continue; + if (path && - ((strcmp(path, stats[i].f_mntonname) != 0) && - (strcmp(path, stats[i].f_mntfromname) != 0) && - (strcmp(rpath, stats[i].f_mntonname) != 0) && - (strcmp(rpath, stats[i].f_mntfromname) != 0))) + ((strcmp(rpath, rmntonname) != 0) && + (strcmp(rpath, rmntfromname) != 0))) continue; /* TODO: external log and realtime device? */ (void) fs_table_insert(stats[i].f_mntonname, 0, @@ -369,7 +380,6 @@ fs_table_initialise_mounts( break; } } - free(rpath); if (path && !found) error = ENXIO;