- 02 Jan, 2009 15 commits
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Sukadev Bhattiprolu authored
To support containers, allow multiple instances of devpts filesystem, such that indices of ptys allocated in one instance are independent of ptys allocated in other instances of devpts. But to preserve backward compatibility, enable this support for multiple instances only if: - CONFIG_DEVPTS_MULTIPLE_INSTANCES is set to Y, and - '-o newinstance' mount option is specified while mounting devpts To use multi-instance mount, a container startup script could: $ ns_exec -cm /bin/bash $ umount /dev/pts $ mount -t devpts -o newinstance lxcpts /dev/pts $ mount -o bind /dev/pts/ptmx /dev/ptmx $ /usr/sbin/sshd -p 1234 where 'ns_exec -cm /bin/bash' is calls clone() with CLONE_NEWNS flag and execs /bin/bash in the child process. A pty created by the sshd is not visible in the original mount of /dev/pts. USER-SPACE-IMPACT: - See Documentation/fs/devpts.txt (included in next patch) for user- space impact in multi-instance and mixed-mode operation. TODO: - Update mount(8), pts(4) man pages. Highlight impact of not redirecting /dev/ptmx to /dev/pts/ptmx after a multi-instance mount. Changelog[v6]: - [Dave Hansen] Use new get_init_pts_sb() interface - [Serge Hallyn] Don't bother displaying 'newinstance' in show_options - [Serge Hallyn] Use macros (PARSE_REMOUNT/PARSE_MOUNT) instead of 0/1. - [Serge Hallyn] Check error return from get_sb_single() (now get_init_pts_sb()) - devpts_pty_kill(): don't dput error dentries Changelog[v5]: - Move get_sb_ref() definition to earlier patch - Move usage info to Documentation/filesystems/devpts.txt (next patch) - Make ptmx node even in init_pts_ns, now that default mode is 0000 (defined in earlier patch, enabled here). - Cache ptmx dentry and use to update mode during remount (defined in earlier patch, enabled here). - Bugfix: explicitly ignore newinstance on remount (if newinstance was specified on remount of initial mount, it would be ignored but /proc/mounts would imply that the option was set) Changelog[v4]: - Update patch description to address H. Peter Anvin's comments - Consolidate multi-instance mode code under new config token, CONFIG_DEVPTS_MULTIPLE_INSTANCE. - Move usage-details from patch description to Documentation/fs/devpts.txt Changelog[v3]: - Rename new mount option to 'newinstance' - Create ptmx nodes only in 'newinstance' mounts - Bugfix: parse_mount_options() modifies @data but since we need to parse the @data twice (once in devpts_get_sb() and once during do_remount_sb()), parse a local copy of @data in devpts_get_sb(). (restructured code in devpts_get_sb() to fix this) Changelog[v2]: - Support both single-mount and multiple-mount semantics and provide '-onewmnt' option to select the semantics. Signed-off-by:
Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by:
Alan Cox <alan@redhat.com> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Sukadev Bhattiprolu authored
See comments in the function header for details. The new interface will be used in a follow-on patch. Changelog [v2]: [Dave Hansen] Replace get_sb_ref() in fs/super.c with get_init_pts_sb() and make the new interface private to devpts Signed-off-by:
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Sukadev Bhattiprolu authored
/dev/ptmx is closely tied to the devpts filesystem. An open of /dev/ptmx, allocates the next pty index and the associated device shows up in the devpts fs as /dev/pts/n. Wih multiple instancs of devpts filesystem, during an open of /dev/ptmx we would be unable to determine which instance of the devpts is being accessed. So we move the 'ptmx' node into /dev/pts and use the inode of the 'ptmx' node to identify the superblock and hence the devpts instance. This patch adds ability for the kernel to internally create the [ptmx, c, 5:2] device when mounting devpts filesystem. Since the ptmx node in devpts is new and may surprise some userspace scripts, the default permissions for the new node is 0000. These permissions can be changed either using chmod or by remounting with the new '-o ptmxmode=0666' mount option. Changelog[v5]: - [Serge Hallyn bugfix]: Letting new_inode() assign inode number to ptmx can collide with hand-assigning inode numbers to ptys. So, hand-assign specific inode number to ptmx node also. - [Serge Hallyn]: Maybe safer to grab root dentry mutex while creating ptmx node - [Bugfix with Serge Hallyn] Replace lookup_one_len() in mknod_ptmx() wih d_alloc_name() (lookup during ->get_sb() locks up system). To simplify patchset, fold the ptmx_dentry patch into this. Changelog[v4]: - Change default permissions of pts/ptmx node to 0000. - Move code for ptmxmode under #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES. Changelog[v3]: - Rename ptmx_mode to ptmxmode (for consistency with 'newinstance') Changelog[v2]: - [H. Peter Anvin] Remove mknod() system call support and create the ptmx node internally. Changelog[v1]: - Earlier version of this patch enabled creating /dev/pts/tty as well. As pointed out by Al Viro and H. Peter Anvin, that is not really necessary. Signed-off-by:
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Sukadev Bhattiprolu authored
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Sukadev Bhattiprolu authored
Move code to parse mount options into a separate function so it can (later) be shared between mount and remount operations. Signed-off-by:
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Sukadev Bhattiprolu authored
With support for multiple mounts of devpts, the 'config' structure really represents per-mount options rather than config parameters. Rename 'config' structure to 'pts_mount_opts' and store it in the super-block. Signed-off-by:
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Sukadev Bhattiprolu authored
To enable multiple mounts of devpts, 'allocated_ptys' must be a per-mount variable rather than a global variable. Move 'allocated_ptys' into the super_block's s_fs_info. Changelog[v2]: Define and use DEVPTS_SB() wrapper. Signed-off-by:
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Sukadev Bhattiprolu authored
Remove the 'devpts_root' global variable and find the root dentry using the super_block. The super-block can be found from the device inode, using the new wrapper, pts_sb_from_inode(). Changelog: This patch is based on an earlier patchset from Serge Hallyn and Matt Helsley. Signed-off-by:
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Alan Cox authored
Now the main work is done its polishing time Signed-off-by:
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Joe Peterson authored
Fixes the loss of echoed (and other ldisc-generated characters) when the tty is stopped or when the driver output buffer is full (happens frequently for input during continuous program output, such as ^C) and removes the Big Kernel Lock from the N_TTY line discipline. Adds an "echo buffer" to the N_TTY line discipline that handles all ldisc-generated output (including echoed characters). Along with the loss of characters, this also fixes the associated loss of sync between tty output and the ldisc state when characters cannot be immediately written to the tty driver. The echo buffer stores (in addition to characters) state operations that need to be done at the time of character output (like management of the column position). This allows echo to cooperate correctly with program output, since the ldisc state remains consistent with actual characters written. Since the echo buffer code now isolates the tty column state code to the process_out* and process_echoes functions, we can remove the Big Kernel Lock (BKL) and replace it with mutex locks. Highlights are: * Handles echo (and other ldisc output) when tty driver buffer is full - continuous program output can block echo * Saves echo when tty is in stopped state (e.g. ^S) - (e.g.: ^Q will correctly cause held characters to be released for output) * Control character pairs (e.g. "^C") are treated atomically and not split up by interleaved program output * Line discipline state is kept consistent with characters sent to the tty driver * Remove the big kernel lock (BKL) from N_TTY line discipline Signed-off-by:
Joe Peterson <joe@skyrush.com> Signed-off-by:
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Sonic Zhang authored
Signed-off-by:
Sonic Zhang <sonic.zhang@analog.com> Signed-off-by:
Bryan Wu <cooloney@kernel.org> Signed-off-by:
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Sonic Zhang authored
Add spin_lock_irqsave() when receive and transfer data. Signed-off-by:
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Sonic Zhang authored
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Graf Yang authored
Bug description: The IRDA receiver may can't receiving any more after processed some signals. To duplicate this issue is put three IRDA devices together, one blackfin, two none blackfin, they will detect each other. Let one none blackfin devices irdaping the blackfin devices, when it stopped print out ping information, it is the time that blackfin stoped receiving, the time is random. The related register bit is OK, the other devices is sending data continuously. But no interrupt come. Fixing: I tried Michael's suggestion that request the UARTx error interrupt, and reset the IRDA when found FE error. This method helps much, but it can't completely avoid stop. Reset the IRDA before every time sending the data is more safe. Signed-off-by:
Graf Yang <graf.yang@analog.com> Signed-off-by:
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Sonic Zhang authored
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- 31 Dec, 2008 25 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6Linus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (34 commits) nfsd race fixes: jfs nfsd race fixes: reiserfs nfsd race fixes: ext4 nfsd race fixes: ext3 nfsd race fixes: ext2 nfsd/create race fixes, infrastructure filesystem notification: create fs/notify to contain all fs notification fs/block_dev.c: __read_mostly improvement and sb_is_blkdev_sb utilization kill ->dir_notify() filp_cachep can be static in fs/file_table.c fix f_count description in Documentation/filesystems/files.txt make INIT_FS use the __RW_LOCK_UNLOCKED initialization take init_fs to saner place kill vfs_permission pass a struct path * to may_open kill walk_init_root remove incorrect comment in inode_permission expand some comments (d_path / seq_path) correct wrong function name of d_put in kernel document and source comment fix switch_names() breakage in short-to-short case ...
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Dave Kleikamp authored
jfs version of Al Viro's nfsd race patches Signed-off-by:
Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
... and the same for reiserfs. The difference here is that we need insert_inode_locked4() to match iget5_locked(). Signed-off-by: -
Al Viro authored
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Al Viro authored
ext3 analog of the previous patch Signed-off-by: -
Al Viro authored
* make ext2_new_inode() put the inode into icache in locked state * do not unlock until the inode is fully set up; otherwise nfsd might pick it in half-baked state. * make sure that ext2_new_inode() does *not* lead to two inodes with the same inumber hashed at the same time; otherwise a bogus fhandle coming from nfsd might race with inode creation: nfsd: iget_locked() creates inode nfsd: try to read from disk, block on that. ext2_new_inode(): allocate inode with that inumber ext2_new_inode(): insert it into icache, set it up and dirty ext2_write_inode(): get the relevant part of inode table in cache, set the entry for our inode (and start writing to disk) nfsd: get CPU again, look into inode table, see nice and sane on-disk inode, set the in-core inode from it oops - we have two in-core inodes with the same inumber live in icache, both used for IO. Welcome to fs corruption... Signed-off-by: -
Al Viro authored
new helpers - insert_inode_locked() and insert_inode_locked4(). Hash new inode, making sure that there's no such inode in icache already. If there is and it does not end up unhashed (as would happen if we have nfsd trying to resolve a bogus fhandle), fail. Otherwise insert our inode into hash and succeed. In either case have i_state set to new+locked; cleanup ends up being simpler with such calling conventions. Signed-off-by: -
Eric Paris authored
Creating a generic filesystem notification interface, fsnotify, which will be used by inotify, dnotify, and eventually fanotify is really starting to clutter the fs directory. This patch simply moves inotify and dnotify into fs/notify/inotify and fs/notify/dnotify respectively to make both current fs/ and future notification tidier. Signed-off-by:
Eric Paris <eparis@redhat.com> Signed-off-by:
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Denis ChengRq authored
- iget5_locked in bdget really needs blockdev_superblock, instead of bd_mnt, so bd_mnt could be just a local variable; - blockdev_superblock really needs __read_mostly, while local var bd_mnt not; - make use of sb_is_blkdev_sb in bd_forget, instead of direct reference to blockdev_superblock. Signed-off-by:
Denis ChengRq <crquan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
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Al Viro authored
Remove the hopelessly misguided ->dir_notify(). The only instance (cifs) has been broken by design from the very beginning; the objects it creates are never destroyed, keep references to struct file they can outlive, nothing that could possibly evict them exists on close(2) path *and* no locking whatsoever is done to prevent races with close(), should the previous, er, deficiencies someday be dealt with. Signed-off-by: -
Eric Dumazet authored
Instead of creating the "filp" kmem_cache in vfs_caches_init(), we can do it a litle be later in files_init(), so that filp_cachep is static to fs/file_table.c Acked-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by:
Eric Dumazet <dada1@cosmosbay.com> Signed-off-by:
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Eric Dumazet authored
Documentation/filesystems/files.txt was not updated when f_count became an atomic_long_t. atomic_long_inc_not_zero() is now used instead of atomic_inc_not_zero() Signed-off-by: -
Steven Rostedt authored
[AV: rediffed on top of unification of init_fs] Initialization of init_fs still uses the deprecated RW_LOCK_UNLOCKED macro. This patch updates it to use the __RW_LOCK_UNLOCKED(lock) macro. Signed-off-by:
Steven Rostedt <srostedt@redhat.com> Signed-off-by:
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Al Viro authored
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Christoph Hellwig authored
With all the nameidata removal there's no point anymore for this helper. Of the three callers left two will go away with the next lookup series anyway. Also add proper kerneldoc to inode_permission as this is the main permission check routine now. Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Christoph Hellwig authored
No need for the nameidata in may_open - a struct path is enough. Signed-off-by:
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Christoph Hellwig authored
walk_init_root is a tiny helper that is marked __always_inline, has just one caller and an unused argument. Just merge it into the caller. Signed-off-by:
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Christoph Hellwig authored
We now pass on all MAY_ flags to the filesystems permission routines, so remove the comment stating the contrary. Signed-off-by:
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Arjan van de Ven authored
Explain that you really need to use the return value of d_path rather than the buffer you passed into it. Also fix the comment for seq_path(), the function arguments changed recently but the comment hadn't been updated in sync. Signed-off-by:
Arjan van de Ven <arjan@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by:
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Zhaolei authored
no function named d_put(), it should be dput(). Impact: fix document and comment, no functionality changed Signed-off-by:
Zhao Lei <zhaolei@cn.fuijtsu.com> Signed-off-by:
Randy Dunlap <rdunlap@xenotime.net> Signed-off-by:
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Al Viro authored
We want ->name.len to match the resulting name on *both* source and target Signed-off-by: -
Duane Griffin authored
Ensure fast symlink targets are NUL-terminated, even if corrupted on-disk. Cc: Sergey S. Kostyliov <rathamahata@php4.ru> Signed-off-by:
Duane Griffin <duaneg@dghda.com> Signed-off-by:
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Duane Griffin authored
Ensure fast symlink targets are NUL-terminated, even if corrupted on-disk. Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by:
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Duane Griffin authored
Ensure fast symlink targets are NUL-terminated, even if corrupted on-disk. Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Duane Griffin authored
Ensure fast symlink targets are NUL-terminated, even if corrupted on-disk. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Theodore Ts'o <tytso@mit.edu> Cc: adilger@sun.com Cc: linux-ext4@vger.kernel.org Signed-off-by:
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