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Commit b4c98f625fffee3a6f633082e9e4be3e952ca2ab

Authored by Joel Becker
Committed by Mark Fasheh
1 parent e478bec0ba
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

configfs: Prevent duplicate subsystem names. 

For all child objects, creation comes through mkdir(2), so duplicate names
are prevented.

Subsystems, though, are registered by client drivers at init_module()/__init
time.  This patch prevents duplicate subsystem names.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Showing 1 changed file with 30 additions and 2 deletions Side-by-side Diff

... ... @@ -86,6 +86,32 @@
86 86 return sd;
87 87 }
88 88  
  89 +/*
  90 + *
  91 + * Return -EEXIST if there is already a configfs element with the same
  92 + * name for the same parent.
  93 + *
  94 + * called with parent inode's i_mutex held
  95 + */
  96 +int configfs_dirent_exists(struct configfs_dirent *parent_sd,
  97 + const unsigned char *new)
  98 +{
  99 + struct configfs_dirent * sd;
  100 +
  101 + list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
  102 + if (sd->s_element) {
  103 + const unsigned char *existing = configfs_get_name(sd);
  104 + if (strcmp(existing, new))
  105 + continue;
  106 + else
  107 + return -EEXIST;
  108 + }
  109 + }
  110 +
  111 + return 0;
  112 +}
  113 +
  114 +
89 115 int configfs_make_dirent(struct configfs_dirent * parent_sd,
90 116 struct dentry * dentry, void * element,
91 117 umode_t mode, int type)
... ... @@ -136,8 +162,10 @@
136 162 int error;
137 163 umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
138 164  
139   - error = configfs_make_dirent(p->d_fsdata, d, k, mode,
140   - CONFIGFS_DIR);
  165 + error = configfs_dirent_exists(p->d_fsdata, d->d_name.name);
  166 + if (!error)
  167 + error = configfs_make_dirent(p->d_fsdata, d, k, mode,
  168 + CONFIGFS_DIR);
141 169 if (!error) {
142 170 error = configfs_create(d, mode, init_dir);
143 171 if (!error) {