| Message ID | 152720689245.9073.17300569813645143102.stgit@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/24/2018 07:08 PM, David Howells wrote: > Alter the AFS automounting code to create and modify an fs_context struct > when parameterising a new mount triggered by an AFS mountpoint rather than > constructing device name and option strings. > > Also remove the cell=, vol= and rwpath options as they are then redundant. > The reason they existed is because the 'device name' may be derived > literally from a mountpoint object in the filesystem, so default cell and > parent-type information needed to be passed in by some other method from > the automount routines. The vol= option didn't end up being used. > > Signed-off-by: David Howells <dhowells@redhat.com> > cc: Eric W. Biederman <ebiederm@redhat.com> > --- > > fs/afs/internal.h | 1 > fs/afs/mntpt.c | 148 +++++++++++++++++++++++++++-------------------------- > fs/afs/super.c | 43 +-------------- > 3 files changed, 79 insertions(+), 113 deletions(-) > > diff --git a/fs/afs/internal.h b/fs/afs/internal.h > index eb6e75e00181..90af5001f8c8 100644 > --- a/fs/afs/internal.h > +++ b/fs/afs/internal.h > @@ -35,7 +35,6 @@ struct pagevec; > struct afs_call; > > struct afs_fs_context { > - bool rwpath; /* T if the parent should be considered R/W */ > bool force; /* T to force cell type */ > bool autocell; /* T if set auto mount operation */ > bool dyn_root; /* T if dynamic root */ > diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c > index c45aa1776591..fc383d727552 100644 > --- a/fs/afs/mntpt.c > +++ b/fs/afs/mntpt.c > @@ -47,6 +47,8 @@ static DECLARE_DELAYED_WORK(afs_mntpt_expiry_timer, afs_mntpt_expiry_timed_out); > > static unsigned long afs_mntpt_expiry_timeout = 10 * 60; > > +static const char afs_root_volume[] = "root.cell"; > + > /* > * no valid lookup procedure on this sort of dir > */ > @@ -68,107 +70,107 @@ static int afs_mntpt_open(struct inode *inode, struct file *file) > } > > /* > - * create a vfsmount to be automounted > + * Set the parameters for the proposed superblock. > */ > -static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt) > +static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt) > { > - struct afs_super_info *as; > - struct vfsmount *mnt; > - struct afs_vnode *vnode; > - struct page *page; > - char *devname, *options; > - bool rwpath = false; > + struct afs_fs_context *ctx = fc->fs_private; > + struct afs_vnode *vnode = AFS_FS_I(d_inode(mntpt)); > + struct afs_cell *cell; > + const char *p; > int ret; > > - _enter("{%pd}", mntpt); > - > - BUG_ON(!d_inode(mntpt)); > - > - ret = -ENOMEM; > - devname = (char *) get_zeroed_page(GFP_KERNEL); > - if (!devname) > - goto error_no_devname; > - > - options = (char *) get_zeroed_page(GFP_KERNEL); > - if (!options) > - goto error_no_options; > - > - vnode = AFS_FS_I(d_inode(mntpt)); > if (test_bit(AFS_VNODE_PSEUDODIR, &vnode->flags)) { > /* if the directory is a pseudo directory, use the d_name */ > - static const char afs_root_cell[] = ":root.cell."; > unsigned size = mntpt->d_name.len; > > - ret = -ENOENT; > - if (size < 2 || size > AFS_MAXCELLNAME) > - goto error_no_page; > + if (size < 2) > + return -ENOENT; > > + p = mntpt->d_name.name; > if (mntpt->d_name.name[0] == '.') { > - devname[0] = '%'; > - memcpy(devname + 1, mntpt->d_name.name + 1, size - 1); > - memcpy(devname + size, afs_root_cell, > - sizeof(afs_root_cell)); > - rwpath = true; > - } else { > - devname[0] = '#'; > - memcpy(devname + 1, mntpt->d_name.name, size); > - memcpy(devname + size + 1, afs_root_cell, > - sizeof(afs_root_cell)); > + size--; > + p++; > + ctx->type = AFSVL_RWVOL; > + ctx->force = true; > + } > + if (size > AFS_MAXCELLNAME) > + return -ENAMETOOLONG; > + > + cell = afs_lookup_cell(ctx->net, p, size, NULL, false); > + if (IS_ERR(cell)) { > + pr_err("kAFS: unable to lookup cell '%pd'\n", mntpt); > + return PTR_ERR(cell); > } > + afs_put_cell(ctx->net, ctx->cell); > + ctx->cell = cell; > + > + ctx->volname = afs_root_volume; > + ctx->volnamesz = sizeof(afs_root_volume) - 1; > } else { > /* read the contents of the AFS special symlink */ > + struct page *page; > loff_t size = i_size_read(d_inode(mntpt)); > char *buf; > > - ret = -EINVAL; > if (size > PAGE_SIZE - 1) > - goto error_no_page; > + return -EINVAL; > > page = read_mapping_page(d_inode(mntpt)->i_mapping, 0, NULL); > - if (IS_ERR(page)) { > - ret = PTR_ERR(page); > - goto error_no_page; > - } > + if (IS_ERR(page)) > + return PTR_ERR(page); > > - ret = -EIO; > - if (PageError(page)) > - goto error; > + if (PageError(page)) { > + put_page(page); > + return -EIO; > + } > > - buf = kmap_atomic(page); > - memcpy(devname, buf, size); > - kunmap_atomic(buf); > + buf = kmap(page); > + ret = vfs_set_fs_source(fc, buf, size); > + kunmap(page); > put_page(page); > - page = NULL; > + if (ret < 0) > + return ret; > } > > - /* work out what options we want */ > - as = AFS_FS_S(mntpt->d_sb); > - if (as->cell) { > - memcpy(options, "cell=", 5); > - strcpy(options + 5, as->cell->name); > - if ((as->volume && as->volume->type == AFSVL_RWVOL) || rwpath) > - strcat(options, ",rwpath"); > - } > + return 0; > +} > > - /* try and do the mount */ > - _debug("--- attempting mount %s -o %s ---", devname, options); > - mnt = vfs_submount(mntpt, &afs_fs_type, devname, > - options, strlen(options) + 1); > - _debug("--- mount result %p ---", mnt); > +/* > + * create a vfsmount to be automounted > + */ > +static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt) > +{ > + struct fs_context *fc; > + struct vfsmount *mnt; > + int ret; > + > + BUG_ON(!d_inode(mntpt)); > + > + fc = vfs_new_fs_context(&afs_fs_type, mntpt, 0, > + FS_CONTEXT_FOR_SUBMOUNT); > + if (IS_ERR(fc)) > + return ERR_CAST(fc); > + > + ret = afs_mntpt_set_params(fc, mntpt); > + if (ret < 0) > + goto error_fc; > + > + ret = vfs_get_tree(fc); > + if (ret < 0) > + goto error_fc; > + > + mnt = vfs_create_mount(fc, 0); > + if (IS_ERR(mnt)) { > + ret = PTR_ERR(mnt); > + goto error_fc; > + } > > - free_page((unsigned long) devname); > - free_page((unsigned long) options); > - _leave(" = %p", mnt); > + put_fs_context(fc); > return mnt; > Why are you performing a put_fs_context(fc) in the success code path? Do we not need a reference of fc anymore? > -error: > - put_page(page); > -error_no_page: > - free_page((unsigned long) options); > -error_no_options: > - free_page((unsigned long) devname); > -error_no_devname: > - _leave(" = %d", ret); > +error_fc: > + put_fs_context(fc); > return ERR_PTR(ret); > } >
Goldwyn Rodrigues <rgoldwyn@suse.de> wrote: Goldwyn Rodrigues <rgoldwyn@suse.de> wrote: > > +static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt) > > +{ > > + struct fs_context *fc; > > + struct vfsmount *mnt; > > + int ret; > > + > > + BUG_ON(!d_inode(mntpt)); > > + > > + fc = vfs_new_fs_context(&afs_fs_type, mntpt, 0, > > + FS_CONTEXT_FOR_SUBMOUNT); > > + if (IS_ERR(fc)) > > + return ERR_CAST(fc); > > + > > + ret = afs_mntpt_set_params(fc, mntpt); > > + if (ret < 0) > > + goto error_fc; > > + > > + ret = vfs_get_tree(fc); > > + if (ret < 0) > > + goto error_fc; > > + > > + mnt = vfs_create_mount(fc, 0); > > + if (IS_ERR(mnt)) { > > + ret = PTR_ERR(mnt); > > + goto error_fc; > > + } > > > > - free_page((unsigned long) devname); > > - free_page((unsigned long) options); > > - _leave(" = %p", mnt); > > + put_fs_context(fc); > > return mnt; > > > Why are you performing a put_fs_context(fc) in the success code path? Do > we not need a reference of fc anymore? No. This is the ->d_automount() hook. The context is created at the top of the function, configuration is done, the superblock is obtained, a mount object is created (for which we get a ref returned). After that point, we don't need the context any more and no one else is going to clean it up for us. David
diff --git a/fs/afs/internal.h b/fs/afs/internal.h index eb6e75e00181..90af5001f8c8 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -35,7 +35,6 @@ struct pagevec; struct afs_call; struct afs_fs_context { - bool rwpath; /* T if the parent should be considered R/W */ bool force; /* T to force cell type */ bool autocell; /* T if set auto mount operation */ bool dyn_root; /* T if dynamic root */ diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c index c45aa1776591..fc383d727552 100644 --- a/fs/afs/mntpt.c +++ b/fs/afs/mntpt.c @@ -47,6 +47,8 @@ static DECLARE_DELAYED_WORK(afs_mntpt_expiry_timer, afs_mntpt_expiry_timed_out); static unsigned long afs_mntpt_expiry_timeout = 10 * 60; +static const char afs_root_volume[] = "root.cell"; + /* * no valid lookup procedure on this sort of dir */ @@ -68,107 +70,107 @@ static int afs_mntpt_open(struct inode *inode, struct file *file) } /* - * create a vfsmount to be automounted + * Set the parameters for the proposed superblock. */ -static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt) +static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt) { - struct afs_super_info *as; - struct vfsmount *mnt; - struct afs_vnode *vnode; - struct page *page; - char *devname, *options; - bool rwpath = false; + struct afs_fs_context *ctx = fc->fs_private; + struct afs_vnode *vnode = AFS_FS_I(d_inode(mntpt)); + struct afs_cell *cell; + const char *p; int ret; - _enter("{%pd}", mntpt); - - BUG_ON(!d_inode(mntpt)); - - ret = -ENOMEM; - devname = (char *) get_zeroed_page(GFP_KERNEL); - if (!devname) - goto error_no_devname; - - options = (char *) get_zeroed_page(GFP_KERNEL); - if (!options) - goto error_no_options; - - vnode = AFS_FS_I(d_inode(mntpt)); if (test_bit(AFS_VNODE_PSEUDODIR, &vnode->flags)) { /* if the directory is a pseudo directory, use the d_name */ - static const char afs_root_cell[] = ":root.cell."; unsigned size = mntpt->d_name.len; - ret = -ENOENT; - if (size < 2 || size > AFS_MAXCELLNAME) - goto error_no_page; + if (size < 2) + return -ENOENT; + p = mntpt->d_name.name; if (mntpt->d_name.name[0] == '.') { - devname[0] = '%'; - memcpy(devname + 1, mntpt->d_name.name + 1, size - 1); - memcpy(devname + size, afs_root_cell, - sizeof(afs_root_cell)); - rwpath = true; - } else { - devname[0] = '#'; - memcpy(devname + 1, mntpt->d_name.name, size); - memcpy(devname + size + 1, afs_root_cell, - sizeof(afs_root_cell)); + size--; + p++; + ctx->type = AFSVL_RWVOL; + ctx->force = true; + } + if (size > AFS_MAXCELLNAME) + return -ENAMETOOLONG; + + cell = afs_lookup_cell(ctx->net, p, size, NULL, false); + if (IS_ERR(cell)) { + pr_err("kAFS: unable to lookup cell '%pd'\n", mntpt); + return PTR_ERR(cell); } + afs_put_cell(ctx->net, ctx->cell); + ctx->cell = cell; + + ctx->volname = afs_root_volume; + ctx->volnamesz = sizeof(afs_root_volume) - 1; } else { /* read the contents of the AFS special symlink */ + struct page *page; loff_t size = i_size_read(d_inode(mntpt)); char *buf; - ret = -EINVAL; if (size > PAGE_SIZE - 1) - goto error_no_page; + return -EINVAL; page = read_mapping_page(d_inode(mntpt)->i_mapping, 0, NULL); - if (IS_ERR(page)) { - ret = PTR_ERR(page); - goto error_no_page; - } + if (IS_ERR(page)) + return PTR_ERR(page); - ret = -EIO; - if (PageError(page)) - goto error; + if (PageError(page)) { + put_page(page); + return -EIO; + } - buf = kmap_atomic(page); - memcpy(devname, buf, size); - kunmap_atomic(buf); + buf = kmap(page); + ret = vfs_set_fs_source(fc, buf, size); + kunmap(page); put_page(page); - page = NULL; + if (ret < 0) + return ret; } - /* work out what options we want */ - as = AFS_FS_S(mntpt->d_sb); - if (as->cell) { - memcpy(options, "cell=", 5); - strcpy(options + 5, as->cell->name); - if ((as->volume && as->volume->type == AFSVL_RWVOL) || rwpath) - strcat(options, ",rwpath"); - } + return 0; +} - /* try and do the mount */ - _debug("--- attempting mount %s -o %s ---", devname, options); - mnt = vfs_submount(mntpt, &afs_fs_type, devname, - options, strlen(options) + 1); - _debug("--- mount result %p ---", mnt); +/* + * create a vfsmount to be automounted + */ +static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt) +{ + struct fs_context *fc; + struct vfsmount *mnt; + int ret; + + BUG_ON(!d_inode(mntpt)); + + fc = vfs_new_fs_context(&afs_fs_type, mntpt, 0, + FS_CONTEXT_FOR_SUBMOUNT); + if (IS_ERR(fc)) + return ERR_CAST(fc); + + ret = afs_mntpt_set_params(fc, mntpt); + if (ret < 0) + goto error_fc; + + ret = vfs_get_tree(fc); + if (ret < 0) + goto error_fc; + + mnt = vfs_create_mount(fc, 0); + if (IS_ERR(mnt)) { + ret = PTR_ERR(mnt); + goto error_fc; + } - free_page((unsigned long) devname); - free_page((unsigned long) options); - _leave(" = %p", mnt); + put_fs_context(fc); return mnt; -error: - put_page(page); -error_no_page: - free_page((unsigned long) options); -error_no_options: - free_page((unsigned long) devname); -error_no_devname: - _leave(" = %d", ret); +error_fc: + put_fs_context(fc); return ERR_PTR(ret); } diff --git a/fs/afs/super.c b/fs/afs/super.c index f0494f36d548..ac97d771f27c 100644 --- a/fs/afs/super.c +++ b/fs/afs/super.c @@ -64,18 +64,12 @@ static atomic_t afs_count_active_inodes; enum { afs_no_opt, - afs_opt_cell, afs_opt_dyn, - afs_opt_rwpath, - afs_opt_vol, afs_opt_autocell, }; static const match_table_t afs_options_list = { - { afs_opt_cell, "cell=%s" }, { afs_opt_dyn, "dyn" }, - { afs_opt_rwpath, "rwpath" }, - { afs_opt_vol, "vol=%s" }, { afs_opt_autocell, "autocell" }, { afs_no_opt, NULL }, }; @@ -194,37 +188,13 @@ static int afs_show_options(struct seq_file *m, struct dentry *root) static int afs_parse_option(struct fs_context *fc, char *opt, size_t len) { struct afs_fs_context *ctx = fc->fs_private; - struct afs_cell *cell; substring_t args[MAX_OPT_ARGS]; - int token, size; + int token; _enter("%s", opt); token = match_token(opt, afs_options_list, args); switch (token) { - case afs_opt_cell: - size = args[0].to - args[0].from; - if (size <= 0) - return -EINVAL; - if (size > AFS_MAXCELLNAME) - return -ENAMETOOLONG; - - rcu_read_lock(); - cell = afs_lookup_cell_rcu(ctx->net, args[0].from, size); - rcu_read_unlock(); - if (IS_ERR(cell)) - return PTR_ERR(cell); - afs_put_cell(ctx->net, ctx->cell); - ctx->cell = cell; - break; - - case afs_opt_rwpath: - ctx->rwpath = true; - break; - - case afs_opt_vol: - return -EINVAL; /* Not required for automount */ - case afs_opt_autocell: ctx->autocell = true; break; @@ -248,8 +218,8 @@ static int afs_parse_option(struct fs_context *fc, char *opt, size_t len) * * This can be one of the following: * "%[cell:]volume[.]" R/W volume - * "#[cell:]volume[.]" R/O or R/W volume (rwpath=0), - * or R/W (rwpath=1) volume + * "#[cell:]volume[.]" R/O or R/W volume (R/O parent), + * or R/W (R/W parent) volume * "%[cell:]volume.readonly" R/O volume * "#[cell:]volume.readonly" R/O volume * "%[cell:]volume.backup" Backup volume @@ -280,9 +250,7 @@ static int afs_parse_source(struct fs_context *fc, char *name) } /* determine the type of volume we're looking for */ - ctx->type = AFSVL_ROVOL; - ctx->force = false; - if (ctx->rwpath || name[0] == '%') { + if (name[0] == '%') { ctx->type = AFSVL_RWVOL; ctx->force = true; } @@ -592,9 +560,6 @@ static int afs_init_fs_context(struct fs_context *fc, struct dentry *reference) struct afs_super_info *src_as; struct afs_cell *cell; - if (current->nsproxy->net_ns != &init_net) - return -EINVAL; - ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL); if (!ctx) return -ENOMEM;
Alter the AFS automounting code to create and modify an fs_context struct when parameterising a new mount triggered by an AFS mountpoint rather than constructing device name and option strings. Also remove the cell=, vol= and rwpath options as they are then redundant. The reason they existed is because the 'device name' may be derived literally from a mountpoint object in the filesystem, so default cell and parent-type information needed to be passed in by some other method from the automount routines. The vol= option didn't end up being used. Signed-off-by: David Howells <dhowells@redhat.com> cc: Eric W. Biederman <ebiederm@redhat.com> --- fs/afs/internal.h | 1 fs/afs/mntpt.c | 148 +++++++++++++++++++++++++++-------------------------- fs/afs/super.c | 43 +-------------- 3 files changed, 79 insertions(+), 113 deletions(-)