cregit-Linux how code gets into the kernel

Release 4.11 drivers/mtd/mtdsuper.c

Directory: drivers/mtd
/* MTD-based superblock management
 *
 * Copyright © 2001-2007 Red Hat, Inc. All Rights Reserved.
 * Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org>
 *
 * Written by:  David Howells <dhowells@redhat.com>
 *              David Woodhouse <dwmw2@infradead.org>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/mtd/super.h>
#include <linux/namei.h>
#include <linux/export.h>
#include <linux/ctype.h>
#include <linux/slab.h>
#include <linux/major.h>

/*
 * compare superblocks to see if they're equivalent
 * - they are if the underlying MTD device is the same
 */

static int get_sb_mtd_compare(struct super_block *sb, void *_mtd) { struct mtd_info *mtd = _mtd; if (sb->s_mtd == mtd) { pr_debug("MTDSB: Match on device %d (\"%s\")\n", mtd->index, mtd->name); return 1; } pr_debug("MTDSB: No match, device %d (\"%s\"), device %d (\"%s\")\n", sb->s_mtd->index, sb->s_mtd->name, mtd->index, mtd->name); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells7497.37%150.00%
Brian Norris22.63%150.00%
Total76100.00%2100.00%

/* * mark the superblock by the MTD device it is using * - set the device number to be the correct MTD block device for pesuperstence * of NFS exports */
static int get_sb_mtd_set(struct super_block *sb, void *_mtd) { struct mtd_info *mtd = _mtd; sb->s_mtd = mtd; sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, mtd->index); sb->s_bdi = mtd->backing_dev_info; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells4484.62%150.00%
Jörn Engel815.38%150.00%
Total52100.00%2100.00%

/* * get a superblock on an MTD-backed filesystem */
static struct dentry *mount_mtd_aux(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct mtd_info *mtd, int (*fill_super)(struct super_block *, void *, int)) { struct super_block *sb; int ret; sb = sget(fs_type, get_sb_mtd_compare, get_sb_mtd_set, flags, mtd); if (IS_ERR(sb)) goto out_error; if (sb->s_root) goto already_mounted; /* fresh new superblock */ pr_debug("MTDSB: New superblock for device %d (\"%s\")\n", mtd->index, mtd->name); ret = fill_super(sb, data, flags & MS_SILENT ? 1 : 0); if (ret < 0) { deactivate_locked_super(sb); return ERR_PTR(ret); } /* go */ sb->s_flags |= MS_ACTIVE; return dget(sb->s_root); /* new mountpoint for an already mounted superblock */ already_mounted: pr_debug("MTDSB: Device %d (\"%s\") is already mounted\n", mtd->index, mtd->name); put_mtd_device(mtd); return dget(sb->s_root); out_error: put_mtd_device(mtd); return ERR_CAST(sb); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells16986.67%240.00%
Al Viro2412.31%240.00%
Brian Norris21.03%120.00%
Total195100.00%5100.00%

/* * get a superblock on an MTD-backed filesystem by MTD device number */
static struct dentry *mount_mtd_nr(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, int mtdnr, int (*fill_super)(struct super_block *, void *, int)) { struct mtd_info *mtd; mtd = get_mtd_device(NULL, mtdnr); if (IS_ERR(mtd)) { pr_debug("MTDSB: Device #%u doesn't appear to exist\n", mtdnr); return ERR_CAST(mtd); } return mount_mtd_aux(fs_type, flags, dev_name, data, mtd, fill_super); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells8386.46%125.00%
Al Viro66.25%125.00%
David Woodhouse66.25%125.00%
Brian Norris11.04%125.00%
Total96100.00%4100.00%

/* * set up an MTD-based superblock */
struct dentry *mount_mtd(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, int (*fill_super)(struct super_block *, void *, int)) { #ifdef CONFIG_BLOCK struct block_device *bdev; int ret, major; #endif int mtdnr; if (!dev_name) return ERR_PTR(-EINVAL); pr_debug("MTDSB: dev_name \"%s\"\n", dev_name); /* the preferred way of mounting in future; especially when * CONFIG_BLOCK=n - we specify the underlying MTD device by number or * by name, so that we don't require block device support to be present * in the kernel. */ if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') { if (dev_name[3] == ':') { struct mtd_info *mtd; /* mount by MTD device name */ pr_debug("MTDSB: mtd:%%s, name \"%s\"\n", dev_name + 4); mtd = get_mtd_device_nm(dev_name + 4); if (!IS_ERR(mtd)) return mount_mtd_aux( fs_type, flags, dev_name, data, mtd, fill_super); printk(KERN_NOTICE "MTD:" " MTD device with name \"%s\" not found.\n", dev_name + 4); } else if (isdigit(dev_name[3])) { /* mount by MTD device number name */ char *endptr; mtdnr = simple_strtoul(dev_name + 3, &endptr, 0); if (!*endptr) { /* It was a valid number */ pr_debug("MTDSB: mtd%%d, mtdnr %d\n", mtdnr); return mount_mtd_nr(fs_type, flags, dev_name, data, mtdnr, fill_super); } } } #ifdef CONFIG_BLOCK /* try the old way - the hack where we allowed users to mount * /dev/mtdblock$(n) but didn't actually _use_ the blockdev */ bdev = lookup_bdev(dev_name); if (IS_ERR(bdev)) { ret = PTR_ERR(bdev); pr_debug("MTDSB: lookup_bdev() returned %d\n", ret); return ERR_PTR(ret); } pr_debug("MTDSB: lookup_bdev() returned 0\n"); ret = -EINVAL; major = MAJOR(bdev->bd_dev); mtdnr = MINOR(bdev->bd_dev); bdput(bdev); if (major != MTD_BLOCK_MAJOR) goto not_an_MTD_device; return mount_mtd_nr(fs_type, flags, dev_name, data, mtdnr, fill_super); not_an_MTD_device: #endif /* CONFIG_BLOCK */ if (!(flags & MS_SILENT)) printk(KERN_NOTICE "MTD: Attempt to mount non-MTD device \"%s\"\n", dev_name); return ERR_PTR(-EINVAL); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells27274.73%114.29%
Al Viro4913.46%228.57%
David Woodhouse349.34%228.57%
Brian Norris51.37%114.29%
Ben Hutchings41.10%114.29%
Total364100.00%7100.00%

EXPORT_SYMBOL_GPL(mount_mtd); /* * destroy an MTD-based superblock */
void kill_mtd_super(struct super_block *sb) { generic_shutdown_super(sb); put_mtd_device(sb->s_mtd); sb->s_mtd = NULL; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells28100.00%1100.00%
Total28100.00%1100.00%

EXPORT_SYMBOL_GPL(kill_mtd_super);

Overall Contributors

PersonTokensPropCommitsCommitProp
David Howells69482.03%215.38%
Al Viro809.46%323.08%
David Woodhouse414.85%323.08%
Jörn Engel111.30%17.69%
Brian Norris101.18%17.69%
Ben Hutchings40.47%17.69%
Ezequiel García30.35%17.69%
Paul Gortmaker30.35%17.69%
Total846100.00%13100.00%
Directory: drivers/mtd
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